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/* -*- mode: C++; indent-tabs-mode: nil; -*- |
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* |
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* This file is a part of LEMON, a generic C++ optimization library. |
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* |
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* Copyright (C) 2003-2009 |
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* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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* (Egervary Research Group on Combinatorial Optimization, EGRES). |
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* |
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* Permission to use, modify and distribute this software is granted |
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* provided that this copyright notice appears in all copies. For |
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* precise terms see the accompanying LICENSE file. |
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* |
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* This software is provided "AS IS" with no warranty of any kind, |
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* express or implied, and with no claim as to its suitability for any |
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* purpose. |
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* |
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*/ |
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|
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namespace lemon { |
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|
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/** |
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@defgroup datas Data Structures |
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This group contains the several data structures implemented in LEMON. |
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*/ |
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|
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/** |
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@defgroup graphs Graph Structures |
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@ingroup datas |
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\brief Graph structures implemented in LEMON. |
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|
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The implementation of combinatorial algorithms heavily relies on |
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efficient graph implementations. LEMON offers data structures which are |
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planned to be easily used in an experimental phase of implementation studies, |
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and thereafter the program code can be made efficient by small modifications. |
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|
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The most efficient implementation of diverse applications require the |
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usage of different physical graph implementations. These differences |
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appear in the size of graph we require to handle, memory or time usage |
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limitations or in the set of operations through which the graph can be |
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accessed. LEMON provides several physical graph structures to meet |
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the diverging requirements of the possible users. In order to save on |
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running time or on memory usage, some structures may fail to provide |
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some graph features like arc/edge or node deletion. |
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|
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Alteration of standard containers need a very limited number of |
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operations, these together satisfy the everyday requirements. |
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In the case of graph structures, different operations are needed which do |
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not alter the physical graph, but gives another view. If some nodes or |
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arcs have to be hidden or the reverse oriented graph have to be used, then |
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this is the case. It also may happen that in a flow implementation |
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the residual graph can be accessed by another algorithm, or a node-set |
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is to be shrunk for another algorithm. |
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LEMON also provides a variety of graphs for these requirements called |
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\ref graph_adaptors "graph adaptors". Adaptors cannot be used alone but only |
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in conjunction with other graph representations. |
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|
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You are free to use the graph structure that fit your requirements |
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the best, most graph algorithms and auxiliary data structures can be used |
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with any graph structure. |
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|
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<b>See also:</b> \ref graph_concepts "Graph Structure Concepts". |
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*/ |
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|
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/** |
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@defgroup graph_adaptors Adaptor Classes for Graphs |
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@ingroup graphs |
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\brief Adaptor classes for digraphs and graphs |
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|
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This group contains several useful adaptor classes for digraphs and graphs. |
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|
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The main parts of LEMON are the different graph structures, generic |
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graph algorithms, graph concepts, which couple them, and graph |
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adaptors. While the previous notions are more or less clear, the |
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latter one needs further explanation. Graph adaptors are graph classes |
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which serve for considering graph structures in different ways. |
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|
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A short example makes this much clearer. Suppose that we have an |
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instance \c g of a directed graph type, say ListDigraph and an algorithm |
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\code |
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template <typename Digraph> |
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int algorithm(const Digraph&); |
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\endcode |
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is needed to run on the reverse oriented graph. It may be expensive |
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(in time or in memory usage) to copy \c g with the reversed |
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arcs. In this case, an adaptor class is used, which (according |
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to LEMON \ref concepts::Digraph "digraph concepts") works as a digraph. |
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The adaptor uses the original digraph structure and digraph operations when |
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methods of the reversed oriented graph are called. This means that the adaptor |
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have minor memory usage, and do not perform sophisticated algorithmic |
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actions. The purpose of it is to give a tool for the cases when a |
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graph have to be used in a specific alteration. If this alteration is |
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obtained by a usual construction like filtering the node or the arc set or |
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considering a new orientation, then an adaptor is worthwhile to use. |
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To come back to the reverse oriented graph, in this situation |
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\code |
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template<typename Digraph> class ReverseDigraph; |
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\endcode |
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template class can be used. The code looks as follows |
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\code |
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ListDigraph g; |
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ReverseDigraph<ListDigraph> rg(g); |
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int result = algorithm(rg); |
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\endcode |
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During running the algorithm, the original digraph \c g is untouched. |
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This techniques give rise to an elegant code, and based on stable |
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graph adaptors, complex algorithms can be implemented easily. |
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|
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In flow, circulation and matching problems, the residual |
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graph is of particular importance. Combining an adaptor implementing |
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this with shortest path algorithms or minimum mean cycle algorithms, |
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a range of weighted and cardinality optimization algorithms can be |
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obtained. For other examples, the interested user is referred to the |
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detailed documentation of particular adaptors. |
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|
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The behavior of graph adaptors can be very different. Some of them keep |
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capabilities of the original graph while in other cases this would be |
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meaningless. This means that the concepts that they meet depend |
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on the graph adaptor, and the wrapped graph. |
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For example, if an arc of a reversed digraph is deleted, this is carried |
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out by deleting the corresponding arc of the original digraph, thus the |
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adaptor modifies the original digraph. |
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However in case of a residual digraph, this operation has no sense. |
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|
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Let us stand one more example here to simplify your work. |
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ReverseDigraph has constructor |
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\code |
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ReverseDigraph(Digraph& digraph); |
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\endcode |
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This means that in a situation, when a <tt>const %ListDigraph&</tt> |
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reference to a graph is given, then it have to be instantiated with |
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<tt>Digraph=const %ListDigraph</tt>. |
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\code |
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int algorithm1(const ListDigraph& g) { |
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ReverseDigraph<const ListDigraph> rg(g); |
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return algorithm2(rg); |
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} |
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\endcode |
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*/ |
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|
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/** |
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@defgroup maps Maps |
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@ingroup datas |
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\brief Map structures implemented in LEMON. |
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|
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This group contains the map structures implemented in LEMON. |
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|
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LEMON provides several special purpose maps and map adaptors that e.g. combine |
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new maps from existing ones. |
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|
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<b>See also:</b> \ref map_concepts "Map Concepts". |
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*/ |
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|
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/** |
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@defgroup graph_maps Graph Maps |
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@ingroup maps |
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\brief Special graph-related maps. |
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|
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This group contains maps that are specifically designed to assign |
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values to the nodes and arcs/edges of graphs. |
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|
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If you are looking for the standard graph maps (\c NodeMap, \c ArcMap, |
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\c EdgeMap), see the \ref graph_concepts "Graph Structure Concepts". |
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*/ |
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|
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/** |
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\defgroup map_adaptors Map Adaptors |
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\ingroup maps |
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\brief Tools to create new maps from existing ones |
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|
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This group contains map adaptors that are used to create "implicit" |
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maps from other maps. |
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|
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Most of them are \ref concepts::ReadMap "read-only maps". |
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They can make arithmetic and logical operations between one or two maps |
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(negation, shifting, addition, multiplication, logical 'and', 'or', |
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'not' etc.) or e.g. convert a map to another one of different Value type. |
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|
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The typical usage of this classes is passing implicit maps to |
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algorithms. If a function type algorithm is called then the function |
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type map adaptors can be used comfortable. For example let's see the |
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usage of map adaptors with the \c graphToEps() function. |
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\code |
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Color nodeColor(int deg) { |
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if (deg >= 2) { |
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return Color(0.5, 0.0, 0.5); |
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} else if (deg == 1) { |
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return Color(1.0, 0.5, 1.0); |
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} else { |
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return Color(0.0, 0.0, 0.0); |
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} |
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} |
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|
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Digraph::NodeMap<int> degree_map(graph); |
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|
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graphToEps(graph, "graph.eps") |
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.coords(coords).scaleToA4().undirected() |
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.nodeColors(composeMap(functorToMap(nodeColor), degree_map)) |
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.run(); |
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\endcode |
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The \c functorToMap() function makes an \c int to \c Color map from the |
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\c nodeColor() function. The \c composeMap() compose the \c degree_map |
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and the previously created map. The composed map is a proper function to |
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get the color of each node. |
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|
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The usage with class type algorithms is little bit harder. In this |
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case the function type map adaptors can not be used, because the |
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function map adaptors give back temporary objects. |
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\code |
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Digraph graph; |
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|
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typedef Digraph::ArcMap<double> DoubleArcMap; |
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DoubleArcMap length(graph); |
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DoubleArcMap speed(graph); |
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|
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typedef DivMap<DoubleArcMap, DoubleArcMap> TimeMap; |
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TimeMap time(length, speed); |
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|
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Dijkstra<Digraph, TimeMap> dijkstra(graph, time); |
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dijkstra.run(source, target); |
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\endcode |
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We have a length map and a maximum speed map on the arcs of a digraph. |
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The minimum time to pass the arc can be calculated as the division of |
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the two maps which can be done implicitly with the \c DivMap template |
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class. We use the implicit minimum time map as the length map of the |
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\c Dijkstra algorithm. |
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*/ |
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|
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/** |
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@defgroup paths Path Structures |
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@ingroup datas |
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\brief %Path structures implemented in LEMON. |
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|
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This group contains the path structures implemented in LEMON. |
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|
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LEMON provides flexible data structures to work with paths. |
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All of them have similar interfaces and they can be copied easily with |
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assignment operators and copy constructors. This makes it easy and |
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efficient to have e.g. the Dijkstra algorithm to store its result in |
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any kind of path structure. |
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|
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\sa \ref concepts::Path "Path concept" |
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*/ |
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|
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/** |
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@defgroup heaps Heap Structures |
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@ingroup datas |
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\brief %Heap structures implemented in LEMON. |
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|
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This group contains the heap structures implemented in LEMON. |
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|
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LEMON provides several heap classes. They are efficient implementations |
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of the abstract data type \e priority \e queue. They store items with |
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specified values called \e priorities in such a way that finding and |
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removing the item with minimum priority are efficient. |
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The basic operations are adding and erasing items, changing the priority |
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of an item, etc. |
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|
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Heaps are crucial in several algorithms, such as Dijkstra and Prim. |
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The heap implementations have the same interface, thus any of them can be |
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used easily in such algorithms. |
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|
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\sa \ref concepts::Heap "Heap concept" |
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*/ |
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|
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/** |
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@defgroup matrices Matrices |
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@ingroup datas |
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\brief Two dimensional data storages implemented in LEMON. |
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|
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This group contains two dimensional data storages implemented in LEMON. |
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*/ |
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|
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/** |
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@defgroup auxdat Auxiliary Data Structures |
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@ingroup datas |
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\brief Auxiliary data structures implemented in LEMON. |
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|
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This group contains some data structures implemented in LEMON in |
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order to make it easier to implement combinatorial algorithms. |
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*/ |
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|
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/** |
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@defgroup geomdat Geometric Data Structures |
|
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@ingroup auxdat |
|
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\brief Geometric data structures implemented in LEMON. |
|
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|
|
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This group contains geometric data structures implemented in LEMON. |
|
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|
|
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- \ref lemon::dim2::Point "dim2::Point" implements a two dimensional |
|
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vector with the usual operations. |
|
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- \ref lemon::dim2::Box "dim2::Box" can be used to determine the |
|
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rectangular bounding box of a set of \ref lemon::dim2::Point |
|
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"dim2::Point"'s. |
|
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*/ |
|
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|
|
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/** |
|
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@defgroup matrices Matrices |
|
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@ingroup auxdat |
|
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\brief Two dimensional data storages implemented in LEMON. |
|
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|
|
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This group contains two dimensional data storages implemented in LEMON. |
|
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*/ |
|
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|
|
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/** |
|
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@defgroup algs Algorithms |
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\brief This group contains the several algorithms |
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implemented in LEMON. |
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|
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This group contains the several algorithms |
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implemented in LEMON. |
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*/ |
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|
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/** |
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@defgroup search Graph Search |
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@ingroup algs |
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\brief Common graph search algorithms. |
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|
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This group contains the common graph search algorithms, namely |
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\e breadth-first \e search (BFS) and \e depth-first \e search (DFS). |
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*/ |
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|
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/** |
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@defgroup shortest_path Shortest Path Algorithms |
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@ingroup algs |
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\brief Algorithms for finding shortest paths. |
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|
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This group contains the algorithms for finding shortest paths in digraphs. |
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|
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- \ref Dijkstra algorithm for finding shortest paths from a source node |
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when all arc lengths are non-negative. |
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- \ref BellmanFord "Bellman-Ford" algorithm for finding shortest paths |
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from a source node when arc lenghts can be either positive or negative, |
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but the digraph should not contain directed cycles with negative total |
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length. |
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- \ref FloydWarshall "Floyd-Warshall" and \ref Johnson "Johnson" algorithms |
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for solving the \e all-pairs \e shortest \e paths \e problem when arc |
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lenghts can be either positive or negative, but the digraph should |
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not contain directed cycles with negative total length. |
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- \ref Suurballe A successive shortest path algorithm for finding |
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arc-disjoint paths between two nodes having minimum total length. |
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*/ |
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|
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/** |
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@defgroup spantree Minimum Spanning Tree Algorithms |
|
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@ingroup algs |
|
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\brief Algorithms for finding minimum cost spanning trees and arborescences. |
|
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|
|
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This group contains the algorithms for finding minimum cost spanning |
|
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trees and arborescences. |
|
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*/ |
|
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|
|
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/** |
|
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@defgroup max_flow Maximum Flow Algorithms |
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@ingroup algs |
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\brief Algorithms for finding maximum flows. |
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|
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This group contains the algorithms for finding maximum flows and |
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feasible circulations. |
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|
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The \e maximum \e flow \e problem is to find a flow of maximum value between |
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a single source and a single target. Formally, there is a \f$G=(V,A)\f$ |
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digraph, a \f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function and |
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\f$s, t \in V\f$ source and target nodes. |
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A maximum flow is an \f$f: A\rightarrow\mathbf{R}^+_0\f$ solution of the |
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following optimization problem. |
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|
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\f[ \max\sum_{sv\in A} f(sv) - \sum_{vs\in A} f(vs) \f] |
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\f[ \sum_{uv\in A} f(uv) = \sum_{vu\in A} f(vu) |
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\quad \forall u\in V\setminus\{s,t\} \f] |
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\f[ 0 \leq f(uv) \leq cap(uv) \quad \forall uv\in A \f] |
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|
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LEMON contains several algorithms for solving maximum flow problems: |
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- \ref EdmondsKarp Edmonds-Karp algorithm. |
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- \ref Preflow Goldberg-Tarjan's preflow push-relabel algorithm. |
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- \ref DinitzSleatorTarjan Dinitz's blocking flow algorithm with dynamic trees. |
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- \ref GoldbergTarjan Preflow push-relabel algorithm with dynamic trees. |
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|
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In most cases the \ref Preflow "Preflow" algorithm provides the |
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fastest method for computing a maximum flow. All implementations |
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also provide functions to query the minimum cut, which is the dual |
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problem of maximum flow. |
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|
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\ref Circulation is a preflow push-relabel algorithm implemented directly |
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for finding feasible circulations, which is a somewhat different problem, |
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but it is strongly related to maximum flow. |
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For more information, see \ref Circulation. |
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*/ |
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|
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/** |
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@defgroup min_cost_flow_algs Minimum Cost Flow Algorithms |
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@ingroup algs |
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|
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\brief Algorithms for finding minimum cost flows and circulations. |
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|
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This group contains the algorithms for finding minimum cost flows and |
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circulations. For more information about this problem and its dual |
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solution see \ref min_cost_flow "Minimum Cost Flow Problem". |
367 | 398 |
|
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LEMON contains several algorithms for this problem. |
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- \ref NetworkSimplex Primal Network Simplex algorithm with various |
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pivot strategies. |
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- \ref CostScaling Push-Relabel and Augment-Relabel algorithms based on |
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cost scaling. |
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- \ref CapacityScaling Successive Shortest %Path algorithm with optional |
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capacity scaling. |
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- \ref CancelAndTighten The Cancel and Tighten algorithm. |
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- \ref CycleCanceling Cycle-Canceling algorithms. |
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|
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In general NetworkSimplex is the most efficient implementation, |
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but in special cases other algorithms could be faster. |
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For example, if the total supply and/or capacities are rather small, |
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CapacityScaling is usually the fastest algorithm (without effective scaling). |
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*/ |
383 | 414 |
|
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/** |
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@defgroup min_cut Minimum Cut Algorithms |
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@ingroup algs |
387 | 418 |
|
388 | 419 |
\brief Algorithms for finding minimum cut in graphs. |
389 | 420 |
|
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This group contains the algorithms for finding minimum cut in graphs. |
391 | 422 |
|
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The \e minimum \e cut \e problem is to find a non-empty and non-complete |
393 | 424 |
\f$X\f$ subset of the nodes with minimum overall capacity on |
394 | 425 |
outgoing arcs. Formally, there is a \f$G=(V,A)\f$ digraph, a |
395 | 426 |
\f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function. The minimum |
396 | 427 |
cut is the \f$X\f$ solution of the next optimization problem: |
397 | 428 |
|
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\f[ \min_{X \subset V, X\not\in \{\emptyset, V\}} |
399 |
\sum_{uv\in A |
|
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\sum_{uv\in A: u\in X, v\not\in X}cap(uv) \f] |
|
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|
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LEMON contains several algorithms related to minimum cut problems: |
402 | 433 |
|
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- \ref HaoOrlin "Hao-Orlin algorithm" for calculating minimum cut |
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in directed graphs. |
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- \ref NagamochiIbaraki "Nagamochi-Ibaraki algorithm" for |
406 | 437 |
calculating minimum cut in undirected graphs. |
407 | 438 |
- \ref GomoryHu "Gomory-Hu tree computation" for calculating |
408 | 439 |
all-pairs minimum cut in undirected graphs. |
409 | 440 |
|
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If you want to find minimum cut just between two distinict nodes, |
411 | 442 |
see the \ref max_flow "maximum flow problem". |
412 | 443 |
*/ |
413 | 444 |
|
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/** |
415 |
@defgroup graph_properties Connectivity and Other Graph Properties |
|
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@ingroup algs |
|
417 |
\brief Algorithms for discovering the graph properties |
|
418 |
|
|
419 |
This group contains the algorithms for discovering the graph properties |
|
420 |
like connectivity, bipartiteness, euler property, simplicity etc. |
|
421 |
|
|
422 |
\image html edge_biconnected_components.png |
|
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\image latex edge_biconnected_components.eps "bi-edge-connected components" width=\textwidth |
|
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*/ |
|
425 |
|
|
426 |
/** |
|
427 |
@defgroup planar Planarity Embedding and Drawing |
|
428 |
@ingroup algs |
|
429 |
\brief Algorithms for planarity checking, embedding and drawing |
|
430 |
|
|
431 |
This group contains the algorithms for planarity checking, |
|
432 |
embedding and drawing. |
|
433 |
|
|
434 |
\image html planar.png |
|
435 |
\image latex planar.eps "Plane graph" width=\textwidth |
|
436 |
*/ |
|
437 |
|
|
438 |
/** |
|
439 | 446 |
@defgroup matching Matching Algorithms |
440 | 447 |
@ingroup algs |
441 | 448 |
\brief Algorithms for finding matchings in graphs and bipartite graphs. |
442 | 449 |
|
443 | 450 |
This group contains the algorithms for calculating |
444 | 451 |
matchings in graphs and bipartite graphs. The general matching problem is |
445 | 452 |
finding a subset of the edges for which each node has at most one incident |
446 | 453 |
edge. |
447 | 454 |
|
448 | 455 |
There are several different algorithms for calculate matchings in |
449 | 456 |
graphs. The matching problems in bipartite graphs are generally |
450 | 457 |
easier than in general graphs. The goal of the matching optimization |
451 | 458 |
can be finding maximum cardinality, maximum weight or minimum cost |
452 | 459 |
matching. The search can be constrained to find perfect or |
453 | 460 |
maximum cardinality matching. |
454 | 461 |
|
455 | 462 |
The matching algorithms implemented in LEMON: |
456 | 463 |
- \ref MaxBipartiteMatching Hopcroft-Karp augmenting path algorithm |
457 | 464 |
for calculating maximum cardinality matching in bipartite graphs. |
458 | 465 |
- \ref PrBipartiteMatching Push-relabel algorithm |
459 | 466 |
for calculating maximum cardinality matching in bipartite graphs. |
460 | 467 |
- \ref MaxWeightedBipartiteMatching |
461 | 468 |
Successive shortest path algorithm for calculating maximum weighted |
462 | 469 |
matching and maximum weighted bipartite matching in bipartite graphs. |
463 | 470 |
- \ref MinCostMaxBipartiteMatching |
464 | 471 |
Successive shortest path algorithm for calculating minimum cost maximum |
465 | 472 |
matching in bipartite graphs. |
466 | 473 |
- \ref MaxMatching Edmond's blossom shrinking algorithm for calculating |
467 | 474 |
maximum cardinality matching in general graphs. |
468 | 475 |
- \ref MaxWeightedMatching Edmond's blossom shrinking algorithm for calculating |
469 | 476 |
maximum weighted matching in general graphs. |
470 | 477 |
- \ref MaxWeightedPerfectMatching |
471 | 478 |
Edmond's blossom shrinking algorithm for calculating maximum weighted |
472 | 479 |
perfect matching in general graphs. |
473 | 480 |
|
474 | 481 |
\image html bipartite_matching.png |
475 | 482 |
\image latex bipartite_matching.eps "Bipartite Matching" width=\textwidth |
476 | 483 |
*/ |
477 | 484 |
|
478 | 485 |
/** |
479 |
@defgroup |
|
486 |
@defgroup graph_properties Connectivity and Other Graph Properties |
|
480 | 487 |
@ingroup algs |
481 |
\brief Algorithms for |
|
488 |
\brief Algorithms for discovering the graph properties |
|
482 | 489 |
|
483 |
This group contains the algorithms for finding minimum cost spanning |
|
484 |
trees and arborescences. |
|
490 |
This group contains the algorithms for discovering the graph properties |
|
491 |
like connectivity, bipartiteness, euler property, simplicity etc. |
|
492 |
|
|
493 |
\image html connected_components.png |
|
494 |
\image latex connected_components.eps "Connected components" width=\textwidth |
|
495 |
*/ |
|
496 |
|
|
497 |
/** |
|
498 |
@defgroup planar Planarity Embedding and Drawing |
|
499 |
@ingroup algs |
|
500 |
\brief Algorithms for planarity checking, embedding and drawing |
|
501 |
|
|
502 |
This group contains the algorithms for planarity checking, |
|
503 |
embedding and drawing. |
|
504 |
|
|
505 |
\image html planar.png |
|
506 |
\image latex planar.eps "Plane graph" width=\textwidth |
|
507 |
*/ |
|
508 |
|
|
509 |
/** |
|
510 |
@defgroup approx Approximation Algorithms |
|
511 |
@ingroup algs |
|
512 |
\brief Approximation algorithms. |
|
513 |
|
|
514 |
This group contains the approximation and heuristic algorithms |
|
515 |
implemented in LEMON. |
|
485 | 516 |
*/ |
486 | 517 |
|
487 | 518 |
/** |
488 | 519 |
@defgroup auxalg Auxiliary Algorithms |
489 | 520 |
@ingroup algs |
490 | 521 |
\brief Auxiliary algorithms implemented in LEMON. |
491 | 522 |
|
492 | 523 |
This group contains some algorithms implemented in LEMON |
493 | 524 |
in order to make it easier to implement complex algorithms. |
494 | 525 |
*/ |
495 | 526 |
|
496 | 527 |
/** |
497 |
@defgroup approx Approximation Algorithms |
|
498 |
@ingroup algs |
|
499 |
\brief Approximation algorithms. |
|
500 |
|
|
501 |
This group contains the approximation and heuristic algorithms |
|
502 |
implemented in LEMON. |
|
503 |
*/ |
|
504 |
|
|
505 |
/** |
|
506 | 528 |
@defgroup gen_opt_group General Optimization Tools |
507 | 529 |
\brief This group contains some general optimization frameworks |
508 | 530 |
implemented in LEMON. |
509 | 531 |
|
510 | 532 |
This group contains some general optimization frameworks |
511 | 533 |
implemented in LEMON. |
512 | 534 |
*/ |
513 | 535 |
|
514 | 536 |
/** |
515 | 537 |
@defgroup lp_group Lp and Mip Solvers |
516 | 538 |
@ingroup gen_opt_group |
517 | 539 |
\brief Lp and Mip solver interfaces for LEMON. |
518 | 540 |
|
519 | 541 |
This group contains Lp and Mip solver interfaces for LEMON. The |
520 | 542 |
various LP solvers could be used in the same manner with this |
521 | 543 |
interface. |
522 | 544 |
*/ |
523 | 545 |
|
524 | 546 |
/** |
525 | 547 |
@defgroup lp_utils Tools for Lp and Mip Solvers |
526 | 548 |
@ingroup lp_group |
527 | 549 |
\brief Helper tools to the Lp and Mip solvers. |
528 | 550 |
|
529 | 551 |
This group adds some helper tools to general optimization framework |
530 | 552 |
implemented in LEMON. |
531 | 553 |
*/ |
532 | 554 |
|
533 | 555 |
/** |
534 | 556 |
@defgroup metah Metaheuristics |
535 | 557 |
@ingroup gen_opt_group |
536 | 558 |
\brief Metaheuristics for LEMON library. |
537 | 559 |
|
538 | 560 |
This group contains some metaheuristic optimization tools. |
539 | 561 |
*/ |
540 | 562 |
|
541 | 563 |
/** |
542 | 564 |
@defgroup utils Tools and Utilities |
543 | 565 |
\brief Tools and utilities for programming in LEMON |
544 | 566 |
|
545 | 567 |
Tools and utilities for programming in LEMON. |
546 | 568 |
*/ |
547 | 569 |
|
548 | 570 |
/** |
549 | 571 |
@defgroup gutils Basic Graph Utilities |
550 | 572 |
@ingroup utils |
551 | 573 |
\brief Simple basic graph utilities. |
552 | 574 |
|
553 | 575 |
This group contains some simple basic graph utilities. |
554 | 576 |
*/ |
555 | 577 |
|
556 | 578 |
/** |
557 | 579 |
@defgroup misc Miscellaneous Tools |
558 | 580 |
@ingroup utils |
559 | 581 |
\brief Tools for development, debugging and testing. |
560 | 582 |
|
561 | 583 |
This group contains several useful tools for development, |
562 | 584 |
debugging and testing. |
563 | 585 |
*/ |
564 | 586 |
|
565 | 587 |
/** |
566 | 588 |
@defgroup timecount Time Measuring and Counting |
567 | 589 |
@ingroup misc |
568 | 590 |
\brief Simple tools for measuring the performance of algorithms. |
569 | 591 |
|
570 | 592 |
This group contains simple tools for measuring the performance |
571 | 593 |
of algorithms. |
572 | 594 |
*/ |
573 | 595 |
|
574 | 596 |
/** |
575 | 597 |
@defgroup exceptions Exceptions |
576 | 598 |
@ingroup utils |
577 | 599 |
\brief Exceptions defined in LEMON. |
578 | 600 |
|
579 | 601 |
This group contains the exceptions defined in LEMON. |
580 | 602 |
*/ |
581 | 603 |
|
582 | 604 |
/** |
583 | 605 |
@defgroup io_group Input-Output |
584 | 606 |
\brief Graph Input-Output methods |
585 | 607 |
|
586 | 608 |
This group contains the tools for importing and exporting graphs |
587 | 609 |
and graph related data. Now it supports the \ref lgf-format |
588 | 610 |
"LEMON Graph Format", the \c DIMACS format and the encapsulated |
589 | 611 |
postscript (EPS) format. |
590 | 612 |
*/ |
591 | 613 |
|
592 | 614 |
/** |
593 | 615 |
@defgroup lemon_io LEMON Graph Format |
594 | 616 |
@ingroup io_group |
595 | 617 |
\brief Reading and writing LEMON Graph Format. |
596 | 618 |
|
597 | 619 |
This group contains methods for reading and writing |
598 | 620 |
\ref lgf-format "LEMON Graph Format". |
599 | 621 |
*/ |
600 | 622 |
|
601 | 623 |
/** |
602 | 624 |
@defgroup eps_io Postscript Exporting |
603 | 625 |
@ingroup io_group |
604 | 626 |
\brief General \c EPS drawer and graph exporter |
605 | 627 |
|
606 | 628 |
This group contains general \c EPS drawing methods and special |
607 | 629 |
graph exporting tools. |
608 | 630 |
*/ |
609 | 631 |
|
610 | 632 |
/** |
611 |
@defgroup dimacs_group DIMACS |
|
633 |
@defgroup dimacs_group DIMACS Format |
|
612 | 634 |
@ingroup io_group |
613 | 635 |
\brief Read and write files in DIMACS format |
614 | 636 |
|
615 | 637 |
Tools to read a digraph from or write it to a file in DIMACS format data. |
616 | 638 |
*/ |
617 | 639 |
|
618 | 640 |
/** |
619 | 641 |
@defgroup nauty_group NAUTY Format |
620 | 642 |
@ingroup io_group |
621 | 643 |
\brief Read \e Nauty format |
622 | 644 |
|
623 | 645 |
Tool to read graphs from \e Nauty format data. |
624 | 646 |
*/ |
625 | 647 |
|
626 | 648 |
/** |
627 | 649 |
@defgroup concept Concepts |
628 | 650 |
\brief Skeleton classes and concept checking classes |
629 | 651 |
|
630 | 652 |
This group contains the data/algorithm skeletons and concept checking |
631 | 653 |
classes implemented in LEMON. |
632 | 654 |
|
633 | 655 |
The purpose of the classes in this group is fourfold. |
634 | 656 |
|
635 | 657 |
- These classes contain the documentations of the %concepts. In order |
636 | 658 |
to avoid document multiplications, an implementation of a concept |
637 | 659 |
simply refers to the corresponding concept class. |
638 | 660 |
|
639 | 661 |
- These classes declare every functions, <tt>typedef</tt>s etc. an |
640 | 662 |
implementation of the %concepts should provide, however completely |
641 | 663 |
without implementations and real data structures behind the |
642 | 664 |
interface. On the other hand they should provide nothing else. All |
643 | 665 |
the algorithms working on a data structure meeting a certain concept |
644 | 666 |
should compile with these classes. (Though it will not run properly, |
645 | 667 |
of course.) In this way it is easily to check if an algorithm |
646 | 668 |
doesn't use any extra feature of a certain implementation. |
647 | 669 |
|
648 | 670 |
- The concept descriptor classes also provide a <em>checker class</em> |
649 | 671 |
that makes it possible to check whether a certain implementation of a |
650 | 672 |
concept indeed provides all the required features. |
651 | 673 |
|
652 | 674 |
- Finally, They can serve as a skeleton of a new implementation of a concept. |
653 | 675 |
*/ |
654 | 676 |
|
655 | 677 |
/** |
656 | 678 |
@defgroup graph_concepts Graph Structure Concepts |
657 | 679 |
@ingroup concept |
658 | 680 |
\brief Skeleton and concept checking classes for graph structures |
659 | 681 |
|
660 | 682 |
This group contains the skeletons and concept checking classes of LEMON's |
661 | 683 |
graph structures and helper classes used to implement these. |
662 | 684 |
*/ |
663 | 685 |
|
664 | 686 |
/** |
665 | 687 |
@defgroup map_concepts Map Concepts |
666 | 688 |
@ingroup concept |
667 | 689 |
\brief Skeleton and concept checking classes for maps |
668 | 690 |
|
669 | 691 |
This group contains the skeletons and concept checking classes of maps. |
670 | 692 |
*/ |
671 | 693 |
|
672 | 694 |
/** |
695 |
@defgroup tools Standalone Utility Applications |
|
696 |
|
|
697 |
Some utility applications are listed here. |
|
698 |
|
|
699 |
The standard compilation procedure (<tt>./configure;make</tt>) will compile |
|
700 |
them, as well. |
|
701 |
*/ |
|
702 |
|
|
703 |
/** |
|
673 | 704 |
\anchor demoprograms |
674 | 705 |
|
675 | 706 |
@defgroup demos Demo Programs |
676 | 707 |
|
677 | 708 |
Some demo programs are listed here. Their full source codes can be found in |
678 | 709 |
the \c demo subdirectory of the source tree. |
679 | 710 |
|
680 | 711 |
In order to compile them, use the <tt>make demo</tt> or the |
681 | 712 |
<tt>make check</tt> commands. |
682 | 713 |
*/ |
683 | 714 |
|
684 |
/** |
|
685 |
@defgroup tools Standalone Utility Applications |
|
686 |
|
|
687 |
Some utility applications are listed here. |
|
688 |
|
|
689 |
The standard compilation procedure (<tt>./configure;make</tt>) will compile |
|
690 |
them, as well. |
|
691 |
*/ |
|
692 |
|
|
693 | 715 |
} |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_BFS_H |
20 | 20 |
#define LEMON_BFS_H |
21 | 21 |
|
22 | 22 |
///\ingroup search |
23 | 23 |
///\file |
24 | 24 |
///\brief BFS algorithm. |
25 | 25 |
|
26 | 26 |
#include <lemon/list_graph.h> |
27 | 27 |
#include <lemon/bits/path_dump.h> |
28 | 28 |
#include <lemon/core.h> |
29 | 29 |
#include <lemon/error.h> |
30 | 30 |
#include <lemon/maps.h> |
31 | 31 |
#include <lemon/path.h> |
32 | 32 |
|
33 | 33 |
namespace lemon { |
34 | 34 |
|
35 | 35 |
///Default traits class of Bfs class. |
36 | 36 |
|
37 | 37 |
///Default traits class of Bfs class. |
38 | 38 |
///\tparam GR Digraph type. |
39 | 39 |
template<class GR> |
40 | 40 |
struct BfsDefaultTraits |
41 | 41 |
{ |
42 | 42 |
///The type of the digraph the algorithm runs on. |
43 | 43 |
typedef GR Digraph; |
44 | 44 |
|
45 | 45 |
///\brief The type of the map that stores the predecessor |
46 | 46 |
///arcs of the shortest paths. |
47 | 47 |
/// |
48 | 48 |
///The type of the map that stores the predecessor |
49 | 49 |
///arcs of the shortest paths. |
50 |
///It must |
|
50 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
51 | 51 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
52 | 52 |
///Instantiates a \c PredMap. |
53 | 53 |
|
54 | 54 |
///This function instantiates a \ref PredMap. |
55 | 55 |
///\param g is the digraph, to which we would like to define the |
56 | 56 |
///\ref PredMap. |
57 | 57 |
static PredMap *createPredMap(const Digraph &g) |
58 | 58 |
{ |
59 | 59 |
return new PredMap(g); |
60 | 60 |
} |
61 | 61 |
|
62 | 62 |
///The type of the map that indicates which nodes are processed. |
63 | 63 |
|
64 | 64 |
///The type of the map that indicates which nodes are processed. |
65 |
///It must |
|
65 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
66 |
///By default it is a NullMap. |
|
66 | 67 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
67 | 68 |
///Instantiates a \c ProcessedMap. |
68 | 69 |
|
69 | 70 |
///This function instantiates a \ref ProcessedMap. |
70 | 71 |
///\param g is the digraph, to which |
71 | 72 |
///we would like to define the \ref ProcessedMap |
72 | 73 |
#ifdef DOXYGEN |
73 | 74 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
74 | 75 |
#else |
75 | 76 |
static ProcessedMap *createProcessedMap(const Digraph &) |
76 | 77 |
#endif |
77 | 78 |
{ |
78 | 79 |
return new ProcessedMap(); |
79 | 80 |
} |
80 | 81 |
|
81 | 82 |
///The type of the map that indicates which nodes are reached. |
82 | 83 |
|
83 | 84 |
///The type of the map that indicates which nodes are reached. |
84 |
///It must |
|
85 |
///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
85 | 86 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
86 | 87 |
///Instantiates a \c ReachedMap. |
87 | 88 |
|
88 | 89 |
///This function instantiates a \ref ReachedMap. |
89 | 90 |
///\param g is the digraph, to which |
90 | 91 |
///we would like to define the \ref ReachedMap. |
91 | 92 |
static ReachedMap *createReachedMap(const Digraph &g) |
92 | 93 |
{ |
93 | 94 |
return new ReachedMap(g); |
94 | 95 |
} |
95 | 96 |
|
96 | 97 |
///The type of the map that stores the distances of the nodes. |
97 | 98 |
|
98 | 99 |
///The type of the map that stores the distances of the nodes. |
99 |
///It must |
|
100 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
100 | 101 |
typedef typename Digraph::template NodeMap<int> DistMap; |
101 | 102 |
///Instantiates a \c DistMap. |
102 | 103 |
|
103 | 104 |
///This function instantiates a \ref DistMap. |
104 | 105 |
///\param g is the digraph, to which we would like to define the |
105 | 106 |
///\ref DistMap. |
106 | 107 |
static DistMap *createDistMap(const Digraph &g) |
107 | 108 |
{ |
108 | 109 |
return new DistMap(g); |
109 | 110 |
} |
110 | 111 |
}; |
111 | 112 |
|
112 | 113 |
///%BFS algorithm class. |
113 | 114 |
|
114 | 115 |
///\ingroup search |
115 | 116 |
///This class provides an efficient implementation of the %BFS algorithm. |
116 | 117 |
/// |
117 | 118 |
///There is also a \ref bfs() "function-type interface" for the BFS |
118 | 119 |
///algorithm, which is convenient in the simplier cases and it can be |
119 | 120 |
///used easier. |
120 | 121 |
/// |
121 | 122 |
///\tparam GR The type of the digraph the algorithm runs on. |
122 | 123 |
///The default type is \ref ListDigraph. |
123 | 124 |
#ifdef DOXYGEN |
124 | 125 |
template <typename GR, |
125 | 126 |
typename TR> |
126 | 127 |
#else |
127 | 128 |
template <typename GR=ListDigraph, |
128 | 129 |
typename TR=BfsDefaultTraits<GR> > |
129 | 130 |
#endif |
130 | 131 |
class Bfs { |
131 | 132 |
public: |
132 | 133 |
|
133 | 134 |
///The type of the digraph the algorithm runs on. |
134 | 135 |
typedef typename TR::Digraph Digraph; |
135 | 136 |
|
136 | 137 |
///\brief The type of the map that stores the predecessor arcs of the |
137 | 138 |
///shortest paths. |
138 | 139 |
typedef typename TR::PredMap PredMap; |
139 | 140 |
///The type of the map that stores the distances of the nodes. |
140 | 141 |
typedef typename TR::DistMap DistMap; |
141 | 142 |
///The type of the map that indicates which nodes are reached. |
142 | 143 |
typedef typename TR::ReachedMap ReachedMap; |
143 | 144 |
///The type of the map that indicates which nodes are processed. |
144 | 145 |
typedef typename TR::ProcessedMap ProcessedMap; |
145 | 146 |
///The type of the paths. |
146 | 147 |
typedef PredMapPath<Digraph, PredMap> Path; |
147 | 148 |
|
148 | 149 |
///The \ref BfsDefaultTraits "traits class" of the algorithm. |
149 | 150 |
typedef TR Traits; |
150 | 151 |
|
151 | 152 |
private: |
152 | 153 |
|
153 | 154 |
typedef typename Digraph::Node Node; |
154 | 155 |
typedef typename Digraph::NodeIt NodeIt; |
155 | 156 |
typedef typename Digraph::Arc Arc; |
156 | 157 |
typedef typename Digraph::OutArcIt OutArcIt; |
157 | 158 |
|
158 | 159 |
//Pointer to the underlying digraph. |
159 | 160 |
const Digraph *G; |
160 | 161 |
//Pointer to the map of predecessor arcs. |
161 | 162 |
PredMap *_pred; |
162 | 163 |
//Indicates if _pred is locally allocated (true) or not. |
163 | 164 |
bool local_pred; |
164 | 165 |
//Pointer to the map of distances. |
165 | 166 |
DistMap *_dist; |
166 | 167 |
//Indicates if _dist is locally allocated (true) or not. |
167 | 168 |
bool local_dist; |
168 | 169 |
//Pointer to the map of reached status of the nodes. |
169 | 170 |
ReachedMap *_reached; |
170 | 171 |
//Indicates if _reached is locally allocated (true) or not. |
171 | 172 |
bool local_reached; |
172 | 173 |
//Pointer to the map of processed status of the nodes. |
173 | 174 |
ProcessedMap *_processed; |
174 | 175 |
//Indicates if _processed is locally allocated (true) or not. |
175 | 176 |
bool local_processed; |
176 | 177 |
|
177 | 178 |
std::vector<typename Digraph::Node> _queue; |
178 | 179 |
int _queue_head,_queue_tail,_queue_next_dist; |
179 | 180 |
int _curr_dist; |
180 | 181 |
|
181 | 182 |
//Creates the maps if necessary. |
182 | 183 |
void create_maps() |
183 | 184 |
{ |
184 | 185 |
if(!_pred) { |
185 | 186 |
local_pred = true; |
186 | 187 |
_pred = Traits::createPredMap(*G); |
187 | 188 |
} |
188 | 189 |
if(!_dist) { |
189 | 190 |
local_dist = true; |
190 | 191 |
_dist = Traits::createDistMap(*G); |
191 | 192 |
} |
192 | 193 |
if(!_reached) { |
193 | 194 |
local_reached = true; |
194 | 195 |
_reached = Traits::createReachedMap(*G); |
195 | 196 |
} |
196 | 197 |
if(!_processed) { |
197 | 198 |
local_processed = true; |
198 | 199 |
_processed = Traits::createProcessedMap(*G); |
199 | 200 |
} |
200 | 201 |
} |
201 | 202 |
|
202 | 203 |
protected: |
203 | 204 |
|
204 | 205 |
Bfs() {} |
205 | 206 |
|
206 | 207 |
public: |
207 | 208 |
|
208 | 209 |
typedef Bfs Create; |
209 | 210 |
|
210 | 211 |
///\name Named Template Parameters |
211 | 212 |
|
212 | 213 |
///@{ |
213 | 214 |
|
214 | 215 |
template <class T> |
215 | 216 |
struct SetPredMapTraits : public Traits { |
216 | 217 |
typedef T PredMap; |
217 | 218 |
static PredMap *createPredMap(const Digraph &) |
218 | 219 |
{ |
219 | 220 |
LEMON_ASSERT(false, "PredMap is not initialized"); |
220 | 221 |
return 0; // ignore warnings |
221 | 222 |
} |
222 | 223 |
}; |
223 | 224 |
///\brief \ref named-templ-param "Named parameter" for setting |
224 | 225 |
///\c PredMap type. |
225 | 226 |
/// |
226 | 227 |
///\ref named-templ-param "Named parameter" for setting |
227 | 228 |
///\c PredMap type. |
228 |
///It must |
|
229 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
229 | 230 |
template <class T> |
230 | 231 |
struct SetPredMap : public Bfs< Digraph, SetPredMapTraits<T> > { |
231 | 232 |
typedef Bfs< Digraph, SetPredMapTraits<T> > Create; |
232 | 233 |
}; |
233 | 234 |
|
234 | 235 |
template <class T> |
235 | 236 |
struct SetDistMapTraits : public Traits { |
236 | 237 |
typedef T DistMap; |
237 | 238 |
static DistMap *createDistMap(const Digraph &) |
238 | 239 |
{ |
239 | 240 |
LEMON_ASSERT(false, "DistMap is not initialized"); |
240 | 241 |
return 0; // ignore warnings |
241 | 242 |
} |
242 | 243 |
}; |
243 | 244 |
///\brief \ref named-templ-param "Named parameter" for setting |
244 | 245 |
///\c DistMap type. |
245 | 246 |
/// |
246 | 247 |
///\ref named-templ-param "Named parameter" for setting |
247 | 248 |
///\c DistMap type. |
248 |
///It must |
|
249 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
249 | 250 |
template <class T> |
250 | 251 |
struct SetDistMap : public Bfs< Digraph, SetDistMapTraits<T> > { |
251 | 252 |
typedef Bfs< Digraph, SetDistMapTraits<T> > Create; |
252 | 253 |
}; |
253 | 254 |
|
254 | 255 |
template <class T> |
255 | 256 |
struct SetReachedMapTraits : public Traits { |
256 | 257 |
typedef T ReachedMap; |
257 | 258 |
static ReachedMap *createReachedMap(const Digraph &) |
258 | 259 |
{ |
259 | 260 |
LEMON_ASSERT(false, "ReachedMap is not initialized"); |
260 | 261 |
return 0; // ignore warnings |
261 | 262 |
} |
262 | 263 |
}; |
263 | 264 |
///\brief \ref named-templ-param "Named parameter" for setting |
264 | 265 |
///\c ReachedMap type. |
265 | 266 |
/// |
266 | 267 |
///\ref named-templ-param "Named parameter" for setting |
267 | 268 |
///\c ReachedMap type. |
268 |
///It must |
|
269 |
///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
269 | 270 |
template <class T> |
270 | 271 |
struct SetReachedMap : public Bfs< Digraph, SetReachedMapTraits<T> > { |
271 | 272 |
typedef Bfs< Digraph, SetReachedMapTraits<T> > Create; |
272 | 273 |
}; |
273 | 274 |
|
274 | 275 |
template <class T> |
275 | 276 |
struct SetProcessedMapTraits : public Traits { |
276 | 277 |
typedef T ProcessedMap; |
277 | 278 |
static ProcessedMap *createProcessedMap(const Digraph &) |
278 | 279 |
{ |
279 | 280 |
LEMON_ASSERT(false, "ProcessedMap is not initialized"); |
280 | 281 |
return 0; // ignore warnings |
281 | 282 |
} |
282 | 283 |
}; |
283 | 284 |
///\brief \ref named-templ-param "Named parameter" for setting |
284 | 285 |
///\c ProcessedMap type. |
285 | 286 |
/// |
286 | 287 |
///\ref named-templ-param "Named parameter" for setting |
287 | 288 |
///\c ProcessedMap type. |
288 |
///It must |
|
289 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
289 | 290 |
template <class T> |
290 | 291 |
struct SetProcessedMap : public Bfs< Digraph, SetProcessedMapTraits<T> > { |
291 | 292 |
typedef Bfs< Digraph, SetProcessedMapTraits<T> > Create; |
292 | 293 |
}; |
293 | 294 |
|
294 | 295 |
struct SetStandardProcessedMapTraits : public Traits { |
295 | 296 |
typedef typename Digraph::template NodeMap<bool> ProcessedMap; |
296 | 297 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
297 | 298 |
{ |
298 | 299 |
return new ProcessedMap(g); |
299 | 300 |
return 0; // ignore warnings |
300 | 301 |
} |
301 | 302 |
}; |
302 | 303 |
///\brief \ref named-templ-param "Named parameter" for setting |
303 | 304 |
///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
304 | 305 |
/// |
305 | 306 |
///\ref named-templ-param "Named parameter" for setting |
306 | 307 |
///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
307 | 308 |
///If you don't set it explicitly, it will be automatically allocated. |
308 | 309 |
struct SetStandardProcessedMap : |
309 | 310 |
public Bfs< Digraph, SetStandardProcessedMapTraits > { |
310 | 311 |
typedef Bfs< Digraph, SetStandardProcessedMapTraits > Create; |
311 | 312 |
}; |
312 | 313 |
|
313 | 314 |
///@} |
314 | 315 |
|
315 | 316 |
public: |
316 | 317 |
|
317 | 318 |
///Constructor. |
318 | 319 |
|
319 | 320 |
///Constructor. |
320 | 321 |
///\param g The digraph the algorithm runs on. |
321 | 322 |
Bfs(const Digraph &g) : |
322 | 323 |
G(&g), |
323 | 324 |
_pred(NULL), local_pred(false), |
324 | 325 |
_dist(NULL), local_dist(false), |
325 | 326 |
_reached(NULL), local_reached(false), |
326 | 327 |
_processed(NULL), local_processed(false) |
327 | 328 |
{ } |
328 | 329 |
|
329 | 330 |
///Destructor. |
330 | 331 |
~Bfs() |
331 | 332 |
{ |
332 | 333 |
if(local_pred) delete _pred; |
333 | 334 |
if(local_dist) delete _dist; |
334 | 335 |
if(local_reached) delete _reached; |
335 | 336 |
if(local_processed) delete _processed; |
336 | 337 |
} |
337 | 338 |
|
338 | 339 |
///Sets the map that stores the predecessor arcs. |
339 | 340 |
|
340 | 341 |
///Sets the map that stores the predecessor arcs. |
341 | 342 |
///If you don't use this function before calling \ref run(Node) "run()" |
342 | 343 |
///or \ref init(), an instance will be allocated automatically. |
343 | 344 |
///The destructor deallocates this automatically allocated map, |
344 | 345 |
///of course. |
345 | 346 |
///\return <tt> (*this) </tt> |
346 | 347 |
Bfs &predMap(PredMap &m) |
347 | 348 |
{ |
348 | 349 |
if(local_pred) { |
349 | 350 |
delete _pred; |
350 | 351 |
local_pred=false; |
351 | 352 |
} |
352 | 353 |
_pred = &m; |
353 | 354 |
return *this; |
354 | 355 |
} |
355 | 356 |
|
356 | 357 |
///Sets the map that indicates which nodes are reached. |
357 | 358 |
|
358 | 359 |
///Sets the map that indicates which nodes are reached. |
359 | 360 |
///If you don't use this function before calling \ref run(Node) "run()" |
360 | 361 |
///or \ref init(), an instance will be allocated automatically. |
361 | 362 |
///The destructor deallocates this automatically allocated map, |
362 | 363 |
///of course. |
363 | 364 |
///\return <tt> (*this) </tt> |
364 | 365 |
Bfs &reachedMap(ReachedMap &m) |
365 | 366 |
{ |
366 | 367 |
if(local_reached) { |
367 | 368 |
delete _reached; |
368 | 369 |
local_reached=false; |
369 | 370 |
} |
370 | 371 |
_reached = &m; |
371 | 372 |
return *this; |
372 | 373 |
} |
373 | 374 |
|
374 | 375 |
///Sets the map that indicates which nodes are processed. |
375 | 376 |
|
376 | 377 |
///Sets the map that indicates which nodes are processed. |
377 | 378 |
///If you don't use this function before calling \ref run(Node) "run()" |
378 | 379 |
///or \ref init(), an instance will be allocated automatically. |
379 | 380 |
///The destructor deallocates this automatically allocated map, |
380 | 381 |
///of course. |
381 | 382 |
///\return <tt> (*this) </tt> |
382 | 383 |
Bfs &processedMap(ProcessedMap &m) |
383 | 384 |
{ |
384 | 385 |
if(local_processed) { |
385 | 386 |
delete _processed; |
386 | 387 |
local_processed=false; |
387 | 388 |
} |
388 | 389 |
_processed = &m; |
389 | 390 |
return *this; |
390 | 391 |
} |
391 | 392 |
|
392 | 393 |
///Sets the map that stores the distances of the nodes. |
393 | 394 |
|
394 | 395 |
///Sets the map that stores the distances of the nodes calculated by |
395 | 396 |
///the algorithm. |
396 | 397 |
///If you don't use this function before calling \ref run(Node) "run()" |
397 | 398 |
///or \ref init(), an instance will be allocated automatically. |
398 | 399 |
///The destructor deallocates this automatically allocated map, |
399 | 400 |
///of course. |
400 | 401 |
///\return <tt> (*this) </tt> |
401 | 402 |
Bfs &distMap(DistMap &m) |
402 | 403 |
{ |
403 | 404 |
if(local_dist) { |
404 | 405 |
delete _dist; |
405 | 406 |
local_dist=false; |
406 | 407 |
} |
407 | 408 |
_dist = &m; |
408 | 409 |
return *this; |
409 | 410 |
} |
410 | 411 |
|
411 | 412 |
public: |
412 | 413 |
|
413 | 414 |
///\name Execution Control |
414 | 415 |
///The simplest way to execute the BFS algorithm is to use one of the |
415 | 416 |
///member functions called \ref run(Node) "run()".\n |
416 |
///If you need more control on the execution, first you have to call |
|
417 |
///\ref init(), then you can add several source nodes with |
|
417 |
///If you need better control on the execution, you have to call |
|
418 |
///\ref init() first, then you can add several source nodes with |
|
418 | 419 |
///\ref addSource(). Finally the actual path computation can be |
419 | 420 |
///performed with one of the \ref start() functions. |
420 | 421 |
|
421 | 422 |
///@{ |
422 | 423 |
|
423 | 424 |
///\brief Initializes the internal data structures. |
424 | 425 |
/// |
425 | 426 |
///Initializes the internal data structures. |
426 | 427 |
void init() |
427 | 428 |
{ |
428 | 429 |
create_maps(); |
429 | 430 |
_queue.resize(countNodes(*G)); |
430 | 431 |
_queue_head=_queue_tail=0; |
431 | 432 |
_curr_dist=1; |
432 | 433 |
for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
433 | 434 |
_pred->set(u,INVALID); |
434 | 435 |
_reached->set(u,false); |
435 | 436 |
_processed->set(u,false); |
436 | 437 |
} |
437 | 438 |
} |
438 | 439 |
|
439 | 440 |
///Adds a new source node. |
440 | 441 |
|
441 | 442 |
///Adds a new source node to the set of nodes to be processed. |
442 | 443 |
/// |
443 | 444 |
void addSource(Node s) |
444 | 445 |
{ |
445 | 446 |
if(!(*_reached)[s]) |
446 | 447 |
{ |
447 | 448 |
_reached->set(s,true); |
448 | 449 |
_pred->set(s,INVALID); |
449 | 450 |
_dist->set(s,0); |
450 | 451 |
_queue[_queue_head++]=s; |
451 | 452 |
_queue_next_dist=_queue_head; |
452 | 453 |
} |
453 | 454 |
} |
454 | 455 |
|
455 | 456 |
///Processes the next node. |
456 | 457 |
|
457 | 458 |
///Processes the next node. |
458 | 459 |
/// |
459 | 460 |
///\return The processed node. |
460 | 461 |
/// |
461 | 462 |
///\pre The queue must not be empty. |
462 | 463 |
Node processNextNode() |
463 | 464 |
{ |
464 | 465 |
if(_queue_tail==_queue_next_dist) { |
465 | 466 |
_curr_dist++; |
466 | 467 |
_queue_next_dist=_queue_head; |
467 | 468 |
} |
468 | 469 |
Node n=_queue[_queue_tail++]; |
469 | 470 |
_processed->set(n,true); |
470 | 471 |
Node m; |
471 | 472 |
for(OutArcIt e(*G,n);e!=INVALID;++e) |
472 | 473 |
if(!(*_reached)[m=G->target(e)]) { |
473 | 474 |
_queue[_queue_head++]=m; |
474 | 475 |
_reached->set(m,true); |
475 | 476 |
_pred->set(m,e); |
476 | 477 |
_dist->set(m,_curr_dist); |
477 | 478 |
} |
478 | 479 |
return n; |
479 | 480 |
} |
480 | 481 |
|
481 | 482 |
///Processes the next node. |
482 | 483 |
|
483 | 484 |
///Processes the next node and checks if the given target node |
484 | 485 |
///is reached. If the target node is reachable from the processed |
485 | 486 |
///node, then the \c reach parameter will be set to \c true. |
486 | 487 |
/// |
487 | 488 |
///\param target The target node. |
488 | 489 |
///\retval reach Indicates if the target node is reached. |
489 | 490 |
///It should be initially \c false. |
490 | 491 |
/// |
491 | 492 |
///\return The processed node. |
492 | 493 |
/// |
493 | 494 |
///\pre The queue must not be empty. |
494 | 495 |
Node processNextNode(Node target, bool& reach) |
495 | 496 |
{ |
496 | 497 |
if(_queue_tail==_queue_next_dist) { |
497 | 498 |
_curr_dist++; |
498 | 499 |
_queue_next_dist=_queue_head; |
499 | 500 |
} |
500 | 501 |
Node n=_queue[_queue_tail++]; |
501 | 502 |
_processed->set(n,true); |
502 | 503 |
Node m; |
503 | 504 |
for(OutArcIt e(*G,n);e!=INVALID;++e) |
504 | 505 |
if(!(*_reached)[m=G->target(e)]) { |
505 | 506 |
_queue[_queue_head++]=m; |
506 | 507 |
_reached->set(m,true); |
507 | 508 |
_pred->set(m,e); |
508 | 509 |
_dist->set(m,_curr_dist); |
509 | 510 |
reach = reach || (target == m); |
510 | 511 |
} |
511 | 512 |
return n; |
512 | 513 |
} |
513 | 514 |
|
514 | 515 |
///Processes the next node. |
515 | 516 |
|
516 | 517 |
///Processes the next node and checks if at least one of reached |
517 | 518 |
///nodes has \c true value in the \c nm node map. If one node |
518 | 519 |
///with \c true value is reachable from the processed node, then the |
519 | 520 |
///\c rnode parameter will be set to the first of such nodes. |
520 | 521 |
/// |
521 | 522 |
///\param nm A \c bool (or convertible) node map that indicates the |
522 | 523 |
///possible targets. |
523 | 524 |
///\retval rnode The reached target node. |
524 | 525 |
///It should be initially \c INVALID. |
525 | 526 |
/// |
526 | 527 |
///\return The processed node. |
527 | 528 |
/// |
528 | 529 |
///\pre The queue must not be empty. |
529 | 530 |
template<class NM> |
530 | 531 |
Node processNextNode(const NM& nm, Node& rnode) |
531 | 532 |
{ |
532 | 533 |
if(_queue_tail==_queue_next_dist) { |
533 | 534 |
_curr_dist++; |
534 | 535 |
_queue_next_dist=_queue_head; |
535 | 536 |
} |
536 | 537 |
Node n=_queue[_queue_tail++]; |
537 | 538 |
_processed->set(n,true); |
538 | 539 |
Node m; |
539 | 540 |
for(OutArcIt e(*G,n);e!=INVALID;++e) |
540 | 541 |
if(!(*_reached)[m=G->target(e)]) { |
541 | 542 |
_queue[_queue_head++]=m; |
542 | 543 |
_reached->set(m,true); |
543 | 544 |
_pred->set(m,e); |
544 | 545 |
_dist->set(m,_curr_dist); |
545 | 546 |
if (nm[m] && rnode == INVALID) rnode = m; |
546 | 547 |
} |
547 | 548 |
return n; |
548 | 549 |
} |
549 | 550 |
|
550 | 551 |
///The next node to be processed. |
551 | 552 |
|
552 | 553 |
///Returns the next node to be processed or \c INVALID if the queue |
553 | 554 |
///is empty. |
554 | 555 |
Node nextNode() const |
555 | 556 |
{ |
556 | 557 |
return _queue_tail<_queue_head?_queue[_queue_tail]:INVALID; |
557 | 558 |
} |
558 | 559 |
|
559 | 560 |
///Returns \c false if there are nodes to be processed. |
560 | 561 |
|
561 | 562 |
///Returns \c false if there are nodes to be processed |
562 | 563 |
///in the queue. |
563 | 564 |
bool emptyQueue() const { return _queue_tail==_queue_head; } |
564 | 565 |
|
565 | 566 |
///Returns the number of the nodes to be processed. |
566 | 567 |
|
567 | 568 |
///Returns the number of the nodes to be processed |
568 | 569 |
///in the queue. |
569 | 570 |
int queueSize() const { return _queue_head-_queue_tail; } |
570 | 571 |
|
571 | 572 |
///Executes the algorithm. |
572 | 573 |
|
573 | 574 |
///Executes the algorithm. |
574 | 575 |
/// |
575 | 576 |
///This method runs the %BFS algorithm from the root node(s) |
576 | 577 |
///in order to compute the shortest path to each node. |
577 | 578 |
/// |
578 | 579 |
///The algorithm computes |
579 | 580 |
///- the shortest path tree (forest), |
580 | 581 |
///- the distance of each node from the root(s). |
581 | 582 |
/// |
582 | 583 |
///\pre init() must be called and at least one root node should be |
583 | 584 |
///added with addSource() before using this function. |
584 | 585 |
/// |
585 | 586 |
///\note <tt>b.start()</tt> is just a shortcut of the following code. |
586 | 587 |
///\code |
587 | 588 |
/// while ( !b.emptyQueue() ) { |
588 | 589 |
/// b.processNextNode(); |
589 | 590 |
/// } |
590 | 591 |
///\endcode |
591 | 592 |
void start() |
592 | 593 |
{ |
593 | 594 |
while ( !emptyQueue() ) processNextNode(); |
594 | 595 |
} |
595 | 596 |
|
596 | 597 |
///Executes the algorithm until the given target node is reached. |
597 | 598 |
|
598 | 599 |
///Executes the algorithm until the given target node is reached. |
599 | 600 |
/// |
600 | 601 |
///This method runs the %BFS algorithm from the root node(s) |
601 | 602 |
///in order to compute the shortest path to \c t. |
602 | 603 |
/// |
603 | 604 |
///The algorithm computes |
604 | 605 |
///- the shortest path to \c t, |
605 | 606 |
///- the distance of \c t from the root(s). |
606 | 607 |
/// |
607 | 608 |
///\pre init() must be called and at least one root node should be |
608 | 609 |
///added with addSource() before using this function. |
609 | 610 |
/// |
610 | 611 |
///\note <tt>b.start(t)</tt> is just a shortcut of the following code. |
611 | 612 |
///\code |
612 | 613 |
/// bool reach = false; |
613 | 614 |
/// while ( !b.emptyQueue() && !reach ) { |
614 | 615 |
/// b.processNextNode(t, reach); |
615 | 616 |
/// } |
616 | 617 |
///\endcode |
617 | 618 |
void start(Node t) |
618 | 619 |
{ |
619 | 620 |
bool reach = false; |
620 | 621 |
while ( !emptyQueue() && !reach ) processNextNode(t, reach); |
621 | 622 |
} |
622 | 623 |
|
623 | 624 |
///Executes the algorithm until a condition is met. |
624 | 625 |
|
625 | 626 |
///Executes the algorithm until a condition is met. |
626 | 627 |
/// |
627 | 628 |
///This method runs the %BFS algorithm from the root node(s) in |
628 | 629 |
///order to compute the shortest path to a node \c v with |
629 | 630 |
/// <tt>nm[v]</tt> true, if such a node can be found. |
630 | 631 |
/// |
631 | 632 |
///\param nm A \c bool (or convertible) node map. The algorithm |
632 | 633 |
///will stop when it reaches a node \c v with <tt>nm[v]</tt> true. |
633 | 634 |
/// |
634 | 635 |
///\return The reached node \c v with <tt>nm[v]</tt> true or |
635 | 636 |
///\c INVALID if no such node was found. |
636 | 637 |
/// |
637 | 638 |
///\pre init() must be called and at least one root node should be |
638 | 639 |
///added with addSource() before using this function. |
639 | 640 |
/// |
640 | 641 |
///\note <tt>b.start(nm)</tt> is just a shortcut of the following code. |
641 | 642 |
///\code |
642 | 643 |
/// Node rnode = INVALID; |
643 | 644 |
/// while ( !b.emptyQueue() && rnode == INVALID ) { |
644 | 645 |
/// b.processNextNode(nm, rnode); |
645 | 646 |
/// } |
646 | 647 |
/// return rnode; |
647 | 648 |
///\endcode |
648 | 649 |
template<class NodeBoolMap> |
649 | 650 |
Node start(const NodeBoolMap &nm) |
650 | 651 |
{ |
651 | 652 |
Node rnode = INVALID; |
652 | 653 |
while ( !emptyQueue() && rnode == INVALID ) { |
653 | 654 |
processNextNode(nm, rnode); |
654 | 655 |
} |
655 | 656 |
return rnode; |
656 | 657 |
} |
657 | 658 |
|
658 | 659 |
///Runs the algorithm from the given source node. |
659 | 660 |
|
660 | 661 |
///This method runs the %BFS algorithm from node \c s |
661 | 662 |
///in order to compute the shortest path to each node. |
662 | 663 |
/// |
663 | 664 |
///The algorithm computes |
664 | 665 |
///- the shortest path tree, |
665 | 666 |
///- the distance of each node from the root. |
666 | 667 |
/// |
667 | 668 |
///\note <tt>b.run(s)</tt> is just a shortcut of the following code. |
668 | 669 |
///\code |
669 | 670 |
/// b.init(); |
670 | 671 |
/// b.addSource(s); |
671 | 672 |
/// b.start(); |
672 | 673 |
///\endcode |
673 | 674 |
void run(Node s) { |
674 | 675 |
init(); |
675 | 676 |
addSource(s); |
676 | 677 |
start(); |
677 | 678 |
} |
678 | 679 |
|
679 | 680 |
///Finds the shortest path between \c s and \c t. |
680 | 681 |
|
681 | 682 |
///This method runs the %BFS algorithm from node \c s |
682 | 683 |
///in order to compute the shortest path to node \c t |
683 | 684 |
///(it stops searching when \c t is processed). |
684 | 685 |
/// |
685 | 686 |
///\return \c true if \c t is reachable form \c s. |
686 | 687 |
/// |
687 | 688 |
///\note Apart from the return value, <tt>b.run(s,t)</tt> is just a |
688 | 689 |
///shortcut of the following code. |
689 | 690 |
///\code |
690 | 691 |
/// b.init(); |
691 | 692 |
/// b.addSource(s); |
692 | 693 |
/// b.start(t); |
693 | 694 |
///\endcode |
694 | 695 |
bool run(Node s,Node t) { |
695 | 696 |
init(); |
696 | 697 |
addSource(s); |
697 | 698 |
start(t); |
698 | 699 |
return reached(t); |
699 | 700 |
} |
700 | 701 |
|
701 | 702 |
///Runs the algorithm to visit all nodes in the digraph. |
702 | 703 |
|
703 | 704 |
///This method runs the %BFS algorithm in order to |
704 | 705 |
///compute the shortest path to each node. |
705 | 706 |
/// |
706 | 707 |
///The algorithm computes |
707 | 708 |
///- the shortest path tree (forest), |
708 | 709 |
///- the distance of each node from the root(s). |
709 | 710 |
/// |
710 | 711 |
///\note <tt>b.run(s)</tt> is just a shortcut of the following code. |
711 | 712 |
///\code |
712 | 713 |
/// b.init(); |
713 | 714 |
/// for (NodeIt n(gr); n != INVALID; ++n) { |
714 | 715 |
/// if (!b.reached(n)) { |
715 | 716 |
/// b.addSource(n); |
716 | 717 |
/// b.start(); |
717 | 718 |
/// } |
718 | 719 |
/// } |
719 | 720 |
///\endcode |
720 | 721 |
void run() { |
721 | 722 |
init(); |
722 | 723 |
for (NodeIt n(*G); n != INVALID; ++n) { |
723 | 724 |
if (!reached(n)) { |
724 | 725 |
addSource(n); |
725 | 726 |
start(); |
726 | 727 |
} |
727 | 728 |
} |
728 | 729 |
} |
729 | 730 |
|
730 | 731 |
///@} |
731 | 732 |
|
732 | 733 |
///\name Query Functions |
733 | 734 |
///The results of the BFS algorithm can be obtained using these |
734 | 735 |
///functions.\n |
735 | 736 |
///Either \ref run(Node) "run()" or \ref start() should be called |
736 | 737 |
///before using them. |
737 | 738 |
|
738 | 739 |
///@{ |
739 | 740 |
|
740 |
///The shortest path to |
|
741 |
///The shortest path to the given node. |
|
741 | 742 |
|
742 |
///Returns the shortest path to |
|
743 |
///Returns the shortest path to the given node from the root(s). |
|
743 | 744 |
/// |
744 | 745 |
///\warning \c t should be reached from the root(s). |
745 | 746 |
/// |
746 | 747 |
///\pre Either \ref run(Node) "run()" or \ref init() |
747 | 748 |
///must be called before using this function. |
748 | 749 |
Path path(Node t) const { return Path(*G, *_pred, t); } |
749 | 750 |
|
750 |
///The distance of |
|
751 |
///The distance of the given node from the root(s). |
|
751 | 752 |
|
752 |
///Returns the distance of |
|
753 |
///Returns the distance of the given node from the root(s). |
|
753 | 754 |
/// |
754 | 755 |
///\warning If node \c v is not reached from the root(s), then |
755 | 756 |
///the return value of this function is undefined. |
756 | 757 |
/// |
757 | 758 |
///\pre Either \ref run(Node) "run()" or \ref init() |
758 | 759 |
///must be called before using this function. |
759 | 760 |
int dist(Node v) const { return (*_dist)[v]; } |
760 | 761 |
|
761 |
///Returns the 'previous arc' of the shortest path tree for a node. |
|
762 |
|
|
762 |
///\brief Returns the 'previous arc' of the shortest path tree for |
|
763 |
///the given node. |
|
764 |
/// |
|
763 | 765 |
///This function returns the 'previous arc' of the shortest path |
764 | 766 |
///tree for the node \c v, i.e. it returns the last arc of a |
765 | 767 |
///shortest path from a root to \c v. It is \c INVALID if \c v |
766 | 768 |
///is not reached from the root(s) or if \c v is a root. |
767 | 769 |
/// |
768 | 770 |
///The shortest path tree used here is equal to the shortest path |
769 |
///tree used in \ref predNode(). |
|
771 |
///tree used in \ref predNode() and \ref predMap(). |
|
770 | 772 |
/// |
771 | 773 |
///\pre Either \ref run(Node) "run()" or \ref init() |
772 | 774 |
///must be called before using this function. |
773 | 775 |
Arc predArc(Node v) const { return (*_pred)[v];} |
774 | 776 |
|
775 |
///Returns the 'previous node' of the shortest path tree for a node. |
|
776 |
|
|
777 |
///\brief Returns the 'previous node' of the shortest path tree for |
|
778 |
///the given node. |
|
779 |
/// |
|
777 | 780 |
///This function returns the 'previous node' of the shortest path |
778 | 781 |
///tree for the node \c v, i.e. it returns the last but one node |
779 |
/// |
|
782 |
///of a shortest path from a root to \c v. It is \c INVALID |
|
780 | 783 |
///if \c v is not reached from the root(s) or if \c v is a root. |
781 | 784 |
/// |
782 | 785 |
///The shortest path tree used here is equal to the shortest path |
783 |
///tree used in \ref predArc(). |
|
786 |
///tree used in \ref predArc() and \ref predMap(). |
|
784 | 787 |
/// |
785 | 788 |
///\pre Either \ref run(Node) "run()" or \ref init() |
786 | 789 |
///must be called before using this function. |
787 | 790 |
Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
788 | 791 |
G->source((*_pred)[v]); } |
789 | 792 |
|
790 | 793 |
///\brief Returns a const reference to the node map that stores the |
791 | 794 |
/// distances of the nodes. |
792 | 795 |
/// |
793 | 796 |
///Returns a const reference to the node map that stores the distances |
794 | 797 |
///of the nodes calculated by the algorithm. |
795 | 798 |
/// |
796 | 799 |
///\pre Either \ref run(Node) "run()" or \ref init() |
797 | 800 |
///must be called before using this function. |
798 | 801 |
const DistMap &distMap() const { return *_dist;} |
799 | 802 |
|
800 | 803 |
///\brief Returns a const reference to the node map that stores the |
801 | 804 |
///predecessor arcs. |
802 | 805 |
/// |
803 | 806 |
///Returns a const reference to the node map that stores the predecessor |
804 |
///arcs, which form the shortest path tree. |
|
807 |
///arcs, which form the shortest path tree (forest). |
|
805 | 808 |
/// |
806 | 809 |
///\pre Either \ref run(Node) "run()" or \ref init() |
807 | 810 |
///must be called before using this function. |
808 | 811 |
const PredMap &predMap() const { return *_pred;} |
809 | 812 |
|
810 |
///Checks if |
|
813 |
///Checks if the given node is reached from the root(s). |
|
811 | 814 |
|
812 | 815 |
///Returns \c true if \c v is reached from the root(s). |
813 | 816 |
/// |
814 | 817 |
///\pre Either \ref run(Node) "run()" or \ref init() |
815 | 818 |
///must be called before using this function. |
816 | 819 |
bool reached(Node v) const { return (*_reached)[v]; } |
817 | 820 |
|
818 | 821 |
///@} |
819 | 822 |
}; |
820 | 823 |
|
821 | 824 |
///Default traits class of bfs() function. |
822 | 825 |
|
823 | 826 |
///Default traits class of bfs() function. |
824 | 827 |
///\tparam GR Digraph type. |
825 | 828 |
template<class GR> |
826 | 829 |
struct BfsWizardDefaultTraits |
827 | 830 |
{ |
828 | 831 |
///The type of the digraph the algorithm runs on. |
829 | 832 |
typedef GR Digraph; |
830 | 833 |
|
831 | 834 |
///\brief The type of the map that stores the predecessor |
832 | 835 |
///arcs of the shortest paths. |
833 | 836 |
/// |
834 | 837 |
///The type of the map that stores the predecessor |
835 | 838 |
///arcs of the shortest paths. |
836 |
///It must |
|
839 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
837 | 840 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
838 | 841 |
///Instantiates a PredMap. |
839 | 842 |
|
840 | 843 |
///This function instantiates a PredMap. |
841 | 844 |
///\param g is the digraph, to which we would like to define the |
842 | 845 |
///PredMap. |
843 | 846 |
static PredMap *createPredMap(const Digraph &g) |
844 | 847 |
{ |
845 | 848 |
return new PredMap(g); |
846 | 849 |
} |
847 | 850 |
|
848 | 851 |
///The type of the map that indicates which nodes are processed. |
849 | 852 |
|
850 | 853 |
///The type of the map that indicates which nodes are processed. |
851 |
///It must |
|
854 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
852 | 855 |
///By default it is a NullMap. |
853 | 856 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
854 | 857 |
///Instantiates a ProcessedMap. |
855 | 858 |
|
856 | 859 |
///This function instantiates a ProcessedMap. |
857 | 860 |
///\param g is the digraph, to which |
858 | 861 |
///we would like to define the ProcessedMap. |
859 | 862 |
#ifdef DOXYGEN |
860 | 863 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
861 | 864 |
#else |
862 | 865 |
static ProcessedMap *createProcessedMap(const Digraph &) |
863 | 866 |
#endif |
864 | 867 |
{ |
865 | 868 |
return new ProcessedMap(); |
866 | 869 |
} |
867 | 870 |
|
868 | 871 |
///The type of the map that indicates which nodes are reached. |
869 | 872 |
|
870 | 873 |
///The type of the map that indicates which nodes are reached. |
871 |
///It must |
|
874 |
///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
872 | 875 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
873 | 876 |
///Instantiates a ReachedMap. |
874 | 877 |
|
875 | 878 |
///This function instantiates a ReachedMap. |
876 | 879 |
///\param g is the digraph, to which |
877 | 880 |
///we would like to define the ReachedMap. |
878 | 881 |
static ReachedMap *createReachedMap(const Digraph &g) |
879 | 882 |
{ |
880 | 883 |
return new ReachedMap(g); |
881 | 884 |
} |
882 | 885 |
|
883 | 886 |
///The type of the map that stores the distances of the nodes. |
884 | 887 |
|
885 | 888 |
///The type of the map that stores the distances of the nodes. |
886 |
///It must |
|
889 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
887 | 890 |
typedef typename Digraph::template NodeMap<int> DistMap; |
888 | 891 |
///Instantiates a DistMap. |
889 | 892 |
|
890 | 893 |
///This function instantiates a DistMap. |
891 | 894 |
///\param g is the digraph, to which we would like to define |
892 | 895 |
///the DistMap |
893 | 896 |
static DistMap *createDistMap(const Digraph &g) |
894 | 897 |
{ |
895 | 898 |
return new DistMap(g); |
896 | 899 |
} |
897 | 900 |
|
898 | 901 |
///The type of the shortest paths. |
899 | 902 |
|
900 | 903 |
///The type of the shortest paths. |
901 |
///It must |
|
904 |
///It must conform to the \ref concepts::Path "Path" concept. |
|
902 | 905 |
typedef lemon::Path<Digraph> Path; |
903 | 906 |
}; |
904 | 907 |
|
905 | 908 |
/// Default traits class used by BfsWizard |
906 | 909 |
|
907 |
/// To make it easier to use Bfs algorithm |
|
908 |
/// we have created a wizard class. |
|
909 |
/// This \ref BfsWizard class needs default traits, |
|
910 |
/// as well as the \ref Bfs class. |
|
911 |
/// The \ref BfsWizardBase is a class to be the default traits of the |
|
912 |
/// \ref BfsWizard class. |
|
910 |
/// Default traits class used by BfsWizard. |
|
911 |
/// \tparam GR The type of the digraph. |
|
913 | 912 |
template<class GR> |
914 | 913 |
class BfsWizardBase : public BfsWizardDefaultTraits<GR> |
915 | 914 |
{ |
916 | 915 |
|
917 | 916 |
typedef BfsWizardDefaultTraits<GR> Base; |
918 | 917 |
protected: |
919 | 918 |
//The type of the nodes in the digraph. |
920 | 919 |
typedef typename Base::Digraph::Node Node; |
921 | 920 |
|
922 | 921 |
//Pointer to the digraph the algorithm runs on. |
923 | 922 |
void *_g; |
924 | 923 |
//Pointer to the map of reached nodes. |
925 | 924 |
void *_reached; |
926 | 925 |
//Pointer to the map of processed nodes. |
927 | 926 |
void *_processed; |
928 | 927 |
//Pointer to the map of predecessors arcs. |
929 | 928 |
void *_pred; |
930 | 929 |
//Pointer to the map of distances. |
931 | 930 |
void *_dist; |
932 | 931 |
//Pointer to the shortest path to the target node. |
933 | 932 |
void *_path; |
934 | 933 |
//Pointer to the distance of the target node. |
935 | 934 |
int *_di; |
936 | 935 |
|
937 | 936 |
public: |
938 | 937 |
/// Constructor. |
939 | 938 |
|
940 |
/// This constructor does not require parameters, |
|
939 |
/// This constructor does not require parameters, it initiates |
|
941 | 940 |
/// all of the attributes to \c 0. |
942 | 941 |
BfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
943 | 942 |
_dist(0), _path(0), _di(0) {} |
944 | 943 |
|
945 | 944 |
/// Constructor. |
946 | 945 |
|
947 | 946 |
/// This constructor requires one parameter, |
948 | 947 |
/// others are initiated to \c 0. |
949 | 948 |
/// \param g The digraph the algorithm runs on. |
950 | 949 |
BfsWizardBase(const GR &g) : |
951 | 950 |
_g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
952 | 951 |
_reached(0), _processed(0), _pred(0), _dist(0), _path(0), _di(0) {} |
953 | 952 |
|
954 | 953 |
}; |
955 | 954 |
|
956 | 955 |
/// Auxiliary class for the function-type interface of BFS algorithm. |
957 | 956 |
|
958 | 957 |
/// This auxiliary class is created to implement the |
959 | 958 |
/// \ref bfs() "function-type interface" of \ref Bfs algorithm. |
960 | 959 |
/// It does not have own \ref run(Node) "run()" method, it uses the |
961 | 960 |
/// functions and features of the plain \ref Bfs. |
962 | 961 |
/// |
963 | 962 |
/// This class should only be used through the \ref bfs() function, |
964 | 963 |
/// which makes it easier to use the algorithm. |
965 | 964 |
template<class TR> |
966 | 965 |
class BfsWizard : public TR |
967 | 966 |
{ |
968 | 967 |
typedef TR Base; |
969 | 968 |
|
970 |
///The type of the digraph the algorithm runs on. |
|
971 | 969 |
typedef typename TR::Digraph Digraph; |
972 | 970 |
|
973 | 971 |
typedef typename Digraph::Node Node; |
974 | 972 |
typedef typename Digraph::NodeIt NodeIt; |
975 | 973 |
typedef typename Digraph::Arc Arc; |
976 | 974 |
typedef typename Digraph::OutArcIt OutArcIt; |
977 | 975 |
|
978 |
///\brief The type of the map that stores the predecessor |
|
979 |
///arcs of the shortest paths. |
|
980 | 976 |
typedef typename TR::PredMap PredMap; |
981 |
///\brief The type of the map that stores the distances of the nodes. |
|
982 | 977 |
typedef typename TR::DistMap DistMap; |
983 |
///\brief The type of the map that indicates which nodes are reached. |
|
984 | 978 |
typedef typename TR::ReachedMap ReachedMap; |
985 |
///\brief The type of the map that indicates which nodes are processed. |
|
986 | 979 |
typedef typename TR::ProcessedMap ProcessedMap; |
987 |
///The type of the shortest paths |
|
988 | 980 |
typedef typename TR::Path Path; |
989 | 981 |
|
990 | 982 |
public: |
991 | 983 |
|
992 | 984 |
/// Constructor. |
993 | 985 |
BfsWizard() : TR() {} |
994 | 986 |
|
995 | 987 |
/// Constructor that requires parameters. |
996 | 988 |
|
997 | 989 |
/// Constructor that requires parameters. |
998 | 990 |
/// These parameters will be the default values for the traits class. |
999 | 991 |
/// \param g The digraph the algorithm runs on. |
1000 | 992 |
BfsWizard(const Digraph &g) : |
1001 | 993 |
TR(g) {} |
1002 | 994 |
|
1003 | 995 |
///Copy constructor |
1004 | 996 |
BfsWizard(const TR &b) : TR(b) {} |
1005 | 997 |
|
1006 | 998 |
~BfsWizard() {} |
1007 | 999 |
|
1008 | 1000 |
///Runs BFS algorithm from the given source node. |
1009 | 1001 |
|
1010 | 1002 |
///This method runs BFS algorithm from node \c s |
1011 | 1003 |
///in order to compute the shortest path to each node. |
1012 | 1004 |
void run(Node s) |
1013 | 1005 |
{ |
1014 | 1006 |
Bfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g)); |
1015 | 1007 |
if (Base::_pred) |
1016 | 1008 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
1017 | 1009 |
if (Base::_dist) |
1018 | 1010 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
1019 | 1011 |
if (Base::_reached) |
1020 | 1012 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
1021 | 1013 |
if (Base::_processed) |
1022 | 1014 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
1023 | 1015 |
if (s!=INVALID) |
1024 | 1016 |
alg.run(s); |
1025 | 1017 |
else |
1026 | 1018 |
alg.run(); |
1027 | 1019 |
} |
1028 | 1020 |
|
1029 | 1021 |
///Finds the shortest path between \c s and \c t. |
1030 | 1022 |
|
1031 | 1023 |
///This method runs BFS algorithm from node \c s |
1032 | 1024 |
///in order to compute the shortest path to node \c t |
1033 | 1025 |
///(it stops searching when \c t is processed). |
1034 | 1026 |
/// |
1035 | 1027 |
///\return \c true if \c t is reachable form \c s. |
1036 | 1028 |
bool run(Node s, Node t) |
1037 | 1029 |
{ |
1038 | 1030 |
Bfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g)); |
1039 | 1031 |
if (Base::_pred) |
1040 | 1032 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
1041 | 1033 |
if (Base::_dist) |
1042 | 1034 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
1043 | 1035 |
if (Base::_reached) |
1044 | 1036 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
1045 | 1037 |
if (Base::_processed) |
1046 | 1038 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
1047 | 1039 |
alg.run(s,t); |
1048 | 1040 |
if (Base::_path) |
1049 | 1041 |
*reinterpret_cast<Path*>(Base::_path) = alg.path(t); |
1050 | 1042 |
if (Base::_di) |
1051 | 1043 |
*Base::_di = alg.dist(t); |
1052 | 1044 |
return alg.reached(t); |
1053 | 1045 |
} |
1054 | 1046 |
|
1055 | 1047 |
///Runs BFS algorithm to visit all nodes in the digraph. |
1056 | 1048 |
|
1057 | 1049 |
///This method runs BFS algorithm in order to compute |
1058 | 1050 |
///the shortest path to each node. |
1059 | 1051 |
void run() |
1060 | 1052 |
{ |
1061 | 1053 |
run(INVALID); |
1062 | 1054 |
} |
1063 | 1055 |
|
1064 | 1056 |
template<class T> |
1065 | 1057 |
struct SetPredMapBase : public Base { |
1066 | 1058 |
typedef T PredMap; |
1067 | 1059 |
static PredMap *createPredMap(const Digraph &) { return 0; }; |
1068 | 1060 |
SetPredMapBase(const TR &b) : TR(b) {} |
1069 | 1061 |
}; |
1070 |
///\brief \ref named-func-param "Named parameter" |
|
1071 |
///for setting PredMap object. |
|
1062 |
|
|
1063 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1064 |
///the predecessor map. |
|
1072 | 1065 |
/// |
1073 |
///\ref named-func-param "Named parameter" |
|
1074 |
///for setting PredMap object. |
|
1066 |
///\ref named-templ-param "Named parameter" function for setting |
|
1067 |
///the map that stores the predecessor arcs of the nodes. |
|
1075 | 1068 |
template<class T> |
1076 | 1069 |
BfsWizard<SetPredMapBase<T> > predMap(const T &t) |
1077 | 1070 |
{ |
1078 | 1071 |
Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1079 | 1072 |
return BfsWizard<SetPredMapBase<T> >(*this); |
1080 | 1073 |
} |
1081 | 1074 |
|
1082 | 1075 |
template<class T> |
1083 | 1076 |
struct SetReachedMapBase : public Base { |
1084 | 1077 |
typedef T ReachedMap; |
1085 | 1078 |
static ReachedMap *createReachedMap(const Digraph &) { return 0; }; |
1086 | 1079 |
SetReachedMapBase(const TR &b) : TR(b) {} |
1087 | 1080 |
}; |
1088 |
///\brief \ref named-func-param "Named parameter" |
|
1089 |
///for setting ReachedMap object. |
|
1081 |
|
|
1082 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1083 |
///the reached map. |
|
1090 | 1084 |
/// |
1091 |
/// \ref named-func-param "Named parameter" |
|
1092 |
///for setting ReachedMap object. |
|
1085 |
///\ref named-templ-param "Named parameter" function for setting |
|
1086 |
///the map that indicates which nodes are reached. |
|
1093 | 1087 |
template<class T> |
1094 | 1088 |
BfsWizard<SetReachedMapBase<T> > reachedMap(const T &t) |
1095 | 1089 |
{ |
1096 | 1090 |
Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1097 | 1091 |
return BfsWizard<SetReachedMapBase<T> >(*this); |
1098 | 1092 |
} |
1099 | 1093 |
|
1100 | 1094 |
template<class T> |
1101 | 1095 |
struct SetDistMapBase : public Base { |
1102 | 1096 |
typedef T DistMap; |
1103 | 1097 |
static DistMap *createDistMap(const Digraph &) { return 0; }; |
1104 | 1098 |
SetDistMapBase(const TR &b) : TR(b) {} |
1105 | 1099 |
}; |
1106 |
///\brief \ref named-func-param "Named parameter" |
|
1107 |
///for setting DistMap object. |
|
1100 |
|
|
1101 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1102 |
///the distance map. |
|
1108 | 1103 |
/// |
1109 |
/// \ref named-func-param "Named parameter" |
|
1110 |
///for setting DistMap object. |
|
1104 |
///\ref named-templ-param "Named parameter" function for setting |
|
1105 |
///the map that stores the distances of the nodes calculated |
|
1106 |
///by the algorithm. |
|
1111 | 1107 |
template<class T> |
1112 | 1108 |
BfsWizard<SetDistMapBase<T> > distMap(const T &t) |
1113 | 1109 |
{ |
1114 | 1110 |
Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1115 | 1111 |
return BfsWizard<SetDistMapBase<T> >(*this); |
1116 | 1112 |
} |
1117 | 1113 |
|
1118 | 1114 |
template<class T> |
1119 | 1115 |
struct SetProcessedMapBase : public Base { |
1120 | 1116 |
typedef T ProcessedMap; |
1121 | 1117 |
static ProcessedMap *createProcessedMap(const Digraph &) { return 0; }; |
1122 | 1118 |
SetProcessedMapBase(const TR &b) : TR(b) {} |
1123 | 1119 |
}; |
1124 |
///\brief \ref named-func-param "Named parameter" |
|
1125 |
///for setting ProcessedMap object. |
|
1120 |
|
|
1121 |
///\brief \ref named-func-param "Named parameter" for setting |
|
1122 |
///the processed map. |
|
1126 | 1123 |
/// |
1127 |
/// \ref named-func-param "Named parameter" |
|
1128 |
///for setting ProcessedMap object. |
|
1124 |
///\ref named-templ-param "Named parameter" function for setting |
|
1125 |
///the map that indicates which nodes are processed. |
|
1129 | 1126 |
template<class T> |
1130 | 1127 |
BfsWizard<SetProcessedMapBase<T> > processedMap(const T &t) |
1131 | 1128 |
{ |
1132 | 1129 |
Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1133 | 1130 |
return BfsWizard<SetProcessedMapBase<T> >(*this); |
1134 | 1131 |
} |
1135 | 1132 |
|
1136 | 1133 |
template<class T> |
1137 | 1134 |
struct SetPathBase : public Base { |
1138 | 1135 |
typedef T Path; |
1139 | 1136 |
SetPathBase(const TR &b) : TR(b) {} |
1140 | 1137 |
}; |
1141 | 1138 |
///\brief \ref named-func-param "Named parameter" |
1142 | 1139 |
///for getting the shortest path to the target node. |
1143 | 1140 |
/// |
1144 | 1141 |
///\ref named-func-param "Named parameter" |
1145 | 1142 |
///for getting the shortest path to the target node. |
1146 | 1143 |
template<class T> |
1147 | 1144 |
BfsWizard<SetPathBase<T> > path(const T &t) |
1148 | 1145 |
{ |
1149 | 1146 |
Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1150 | 1147 |
return BfsWizard<SetPathBase<T> >(*this); |
1151 | 1148 |
} |
1152 | 1149 |
|
1153 | 1150 |
///\brief \ref named-func-param "Named parameter" |
1154 | 1151 |
///for getting the distance of the target node. |
1155 | 1152 |
/// |
1156 | 1153 |
///\ref named-func-param "Named parameter" |
1157 | 1154 |
///for getting the distance of the target node. |
1158 | 1155 |
BfsWizard dist(const int &d) |
1159 | 1156 |
{ |
1160 | 1157 |
Base::_di=const_cast<int*>(&d); |
1161 | 1158 |
return *this; |
1162 | 1159 |
} |
1163 | 1160 |
|
1164 | 1161 |
}; |
1165 | 1162 |
|
1166 | 1163 |
///Function-type interface for BFS algorithm. |
1167 | 1164 |
|
1168 | 1165 |
/// \ingroup search |
1169 | 1166 |
///Function-type interface for BFS algorithm. |
1170 | 1167 |
/// |
1171 | 1168 |
///This function also has several \ref named-func-param "named parameters", |
1172 | 1169 |
///they are declared as the members of class \ref BfsWizard. |
1173 | 1170 |
///The following examples show how to use these parameters. |
1174 | 1171 |
///\code |
1175 | 1172 |
/// // Compute shortest path from node s to each node |
1176 | 1173 |
/// bfs(g).predMap(preds).distMap(dists).run(s); |
1177 | 1174 |
/// |
1178 | 1175 |
/// // Compute shortest path from s to t |
1179 | 1176 |
/// bool reached = bfs(g).path(p).dist(d).run(s,t); |
1180 | 1177 |
///\endcode |
1181 | 1178 |
///\warning Don't forget to put the \ref BfsWizard::run(Node) "run()" |
1182 | 1179 |
///to the end of the parameter list. |
1183 | 1180 |
///\sa BfsWizard |
1184 | 1181 |
///\sa Bfs |
1185 | 1182 |
template<class GR> |
1186 | 1183 |
BfsWizard<BfsWizardBase<GR> > |
1187 | 1184 |
bfs(const GR &digraph) |
1188 | 1185 |
{ |
1189 | 1186 |
return BfsWizard<BfsWizardBase<GR> >(digraph); |
1190 | 1187 |
} |
1191 | 1188 |
|
1192 | 1189 |
#ifdef DOXYGEN |
1193 | 1190 |
/// \brief Visitor class for BFS. |
1194 | 1191 |
/// |
1195 | 1192 |
/// This class defines the interface of the BfsVisit events, and |
1196 | 1193 |
/// it could be the base of a real visitor class. |
1197 | 1194 |
template <typename GR> |
1198 | 1195 |
struct BfsVisitor { |
1199 | 1196 |
typedef GR Digraph; |
1200 | 1197 |
typedef typename Digraph::Arc Arc; |
1201 | 1198 |
typedef typename Digraph::Node Node; |
1202 | 1199 |
/// \brief Called for the source node(s) of the BFS. |
1203 | 1200 |
/// |
1204 | 1201 |
/// This function is called for the source node(s) of the BFS. |
1205 | 1202 |
void start(const Node& node) {} |
1206 | 1203 |
/// \brief Called when a node is reached first time. |
1207 | 1204 |
/// |
1208 | 1205 |
/// This function is called when a node is reached first time. |
1209 | 1206 |
void reach(const Node& node) {} |
1210 | 1207 |
/// \brief Called when a node is processed. |
1211 | 1208 |
/// |
1212 | 1209 |
/// This function is called when a node is processed. |
1213 | 1210 |
void process(const Node& node) {} |
1214 | 1211 |
/// \brief Called when an arc reaches a new node. |
1215 | 1212 |
/// |
1216 | 1213 |
/// This function is called when the BFS finds an arc whose target node |
1217 | 1214 |
/// is not reached yet. |
1218 | 1215 |
void discover(const Arc& arc) {} |
1219 | 1216 |
/// \brief Called when an arc is examined but its target node is |
1220 | 1217 |
/// already discovered. |
1221 | 1218 |
/// |
1222 | 1219 |
/// This function is called when an arc is examined but its target node is |
1223 | 1220 |
/// already discovered. |
1224 | 1221 |
void examine(const Arc& arc) {} |
1225 | 1222 |
}; |
1226 | 1223 |
#else |
1227 | 1224 |
template <typename GR> |
1228 | 1225 |
struct BfsVisitor { |
1229 | 1226 |
typedef GR Digraph; |
1230 | 1227 |
typedef typename Digraph::Arc Arc; |
1231 | 1228 |
typedef typename Digraph::Node Node; |
1232 | 1229 |
void start(const Node&) {} |
1233 | 1230 |
void reach(const Node&) {} |
1234 | 1231 |
void process(const Node&) {} |
1235 | 1232 |
void discover(const Arc&) {} |
1236 | 1233 |
void examine(const Arc&) {} |
1237 | 1234 |
|
1238 | 1235 |
template <typename _Visitor> |
1239 | 1236 |
struct Constraints { |
1240 | 1237 |
void constraints() { |
1241 | 1238 |
Arc arc; |
1242 | 1239 |
Node node; |
1243 | 1240 |
visitor.start(node); |
1244 | 1241 |
visitor.reach(node); |
1245 | 1242 |
visitor.process(node); |
1246 | 1243 |
visitor.discover(arc); |
1247 | 1244 |
visitor.examine(arc); |
1248 | 1245 |
} |
1249 | 1246 |
_Visitor& visitor; |
1250 | 1247 |
}; |
1251 | 1248 |
}; |
1252 | 1249 |
#endif |
1253 | 1250 |
|
1254 | 1251 |
/// \brief Default traits class of BfsVisit class. |
1255 | 1252 |
/// |
1256 | 1253 |
/// Default traits class of BfsVisit class. |
1257 | 1254 |
/// \tparam GR The type of the digraph the algorithm runs on. |
1258 | 1255 |
template<class GR> |
1259 | 1256 |
struct BfsVisitDefaultTraits { |
1260 | 1257 |
|
1261 | 1258 |
/// \brief The type of the digraph the algorithm runs on. |
1262 | 1259 |
typedef GR Digraph; |
1263 | 1260 |
|
1264 | 1261 |
/// \brief The type of the map that indicates which nodes are reached. |
1265 | 1262 |
/// |
1266 | 1263 |
/// The type of the map that indicates which nodes are reached. |
1267 |
/// It must |
|
1264 |
/// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
1268 | 1265 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
1269 | 1266 |
|
1270 | 1267 |
/// \brief Instantiates a ReachedMap. |
1271 | 1268 |
/// |
1272 | 1269 |
/// This function instantiates a ReachedMap. |
1273 | 1270 |
/// \param digraph is the digraph, to which |
1274 | 1271 |
/// we would like to define the ReachedMap. |
1275 | 1272 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1276 | 1273 |
return new ReachedMap(digraph); |
1277 | 1274 |
} |
1278 | 1275 |
|
1279 | 1276 |
}; |
1280 | 1277 |
|
1281 | 1278 |
/// \ingroup search |
1282 | 1279 |
/// |
1283 | 1280 |
/// \brief BFS algorithm class with visitor interface. |
1284 | 1281 |
/// |
1285 | 1282 |
/// This class provides an efficient implementation of the BFS algorithm |
1286 | 1283 |
/// with visitor interface. |
1287 | 1284 |
/// |
1288 | 1285 |
/// The BfsVisit class provides an alternative interface to the Bfs |
1289 | 1286 |
/// class. It works with callback mechanism, the BfsVisit object calls |
1290 | 1287 |
/// the member functions of the \c Visitor class on every BFS event. |
1291 | 1288 |
/// |
1292 | 1289 |
/// This interface of the BFS algorithm should be used in special cases |
1293 | 1290 |
/// when extra actions have to be performed in connection with certain |
1294 | 1291 |
/// events of the BFS algorithm. Otherwise consider to use Bfs or bfs() |
1295 | 1292 |
/// instead. |
1296 | 1293 |
/// |
1297 | 1294 |
/// \tparam GR The type of the digraph the algorithm runs on. |
1298 | 1295 |
/// The default type is \ref ListDigraph. |
1299 | 1296 |
/// The value of GR is not used directly by \ref BfsVisit, |
1300 | 1297 |
/// it is only passed to \ref BfsVisitDefaultTraits. |
1301 | 1298 |
/// \tparam VS The Visitor type that is used by the algorithm. |
1302 | 1299 |
/// \ref BfsVisitor "BfsVisitor<GR>" is an empty visitor, which |
1303 | 1300 |
/// does not observe the BFS events. If you want to observe the BFS |
1304 | 1301 |
/// events, you should implement your own visitor class. |
1305 | 1302 |
/// \tparam TR Traits class to set various data types used by the |
1306 | 1303 |
/// algorithm. The default traits class is |
1307 | 1304 |
/// \ref BfsVisitDefaultTraits "BfsVisitDefaultTraits<GR>". |
1308 | 1305 |
/// See \ref BfsVisitDefaultTraits for the documentation of |
1309 | 1306 |
/// a BFS visit traits class. |
1310 | 1307 |
#ifdef DOXYGEN |
1311 | 1308 |
template <typename GR, typename VS, typename TR> |
1312 | 1309 |
#else |
1313 | 1310 |
template <typename GR = ListDigraph, |
1314 | 1311 |
typename VS = BfsVisitor<GR>, |
1315 | 1312 |
typename TR = BfsVisitDefaultTraits<GR> > |
1316 | 1313 |
#endif |
1317 | 1314 |
class BfsVisit { |
1318 | 1315 |
public: |
1319 | 1316 |
|
1320 | 1317 |
///The traits class. |
1321 | 1318 |
typedef TR Traits; |
1322 | 1319 |
|
1323 | 1320 |
///The type of the digraph the algorithm runs on. |
1324 | 1321 |
typedef typename Traits::Digraph Digraph; |
1325 | 1322 |
|
1326 | 1323 |
///The visitor type used by the algorithm. |
1327 | 1324 |
typedef VS Visitor; |
1328 | 1325 |
|
1329 | 1326 |
///The type of the map that indicates which nodes are reached. |
1330 | 1327 |
typedef typename Traits::ReachedMap ReachedMap; |
1331 | 1328 |
|
1332 | 1329 |
private: |
1333 | 1330 |
|
1334 | 1331 |
typedef typename Digraph::Node Node; |
1335 | 1332 |
typedef typename Digraph::NodeIt NodeIt; |
1336 | 1333 |
typedef typename Digraph::Arc Arc; |
1337 | 1334 |
typedef typename Digraph::OutArcIt OutArcIt; |
1338 | 1335 |
|
1339 | 1336 |
//Pointer to the underlying digraph. |
1340 | 1337 |
const Digraph *_digraph; |
1341 | 1338 |
//Pointer to the visitor object. |
1342 | 1339 |
Visitor *_visitor; |
1343 | 1340 |
//Pointer to the map of reached status of the nodes. |
1344 | 1341 |
ReachedMap *_reached; |
1345 | 1342 |
//Indicates if _reached is locally allocated (true) or not. |
1346 | 1343 |
bool local_reached; |
1347 | 1344 |
|
1348 | 1345 |
std::vector<typename Digraph::Node> _list; |
1349 | 1346 |
int _list_front, _list_back; |
1350 | 1347 |
|
1351 | 1348 |
//Creates the maps if necessary. |
1352 | 1349 |
void create_maps() { |
1353 | 1350 |
if(!_reached) { |
1354 | 1351 |
local_reached = true; |
1355 | 1352 |
_reached = Traits::createReachedMap(*_digraph); |
1356 | 1353 |
} |
1357 | 1354 |
} |
1358 | 1355 |
|
1359 | 1356 |
protected: |
1360 | 1357 |
|
1361 | 1358 |
BfsVisit() {} |
1362 | 1359 |
|
1363 | 1360 |
public: |
1364 | 1361 |
|
1365 | 1362 |
typedef BfsVisit Create; |
1366 | 1363 |
|
1367 | 1364 |
/// \name Named Template Parameters |
1368 | 1365 |
|
1369 | 1366 |
///@{ |
1370 | 1367 |
template <class T> |
1371 | 1368 |
struct SetReachedMapTraits : public Traits { |
1372 | 1369 |
typedef T ReachedMap; |
1373 | 1370 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1374 | 1371 |
LEMON_ASSERT(false, "ReachedMap is not initialized"); |
1375 | 1372 |
return 0; // ignore warnings |
1376 | 1373 |
} |
1377 | 1374 |
}; |
1378 | 1375 |
/// \brief \ref named-templ-param "Named parameter" for setting |
1379 | 1376 |
/// ReachedMap type. |
1380 | 1377 |
/// |
1381 | 1378 |
/// \ref named-templ-param "Named parameter" for setting ReachedMap type. |
1382 | 1379 |
template <class T> |
1383 | 1380 |
struct SetReachedMap : public BfsVisit< Digraph, Visitor, |
1384 | 1381 |
SetReachedMapTraits<T> > { |
1385 | 1382 |
typedef BfsVisit< Digraph, Visitor, SetReachedMapTraits<T> > Create; |
1386 | 1383 |
}; |
1387 | 1384 |
///@} |
1388 | 1385 |
|
1389 | 1386 |
public: |
1390 | 1387 |
|
1391 | 1388 |
/// \brief Constructor. |
1392 | 1389 |
/// |
1393 | 1390 |
/// Constructor. |
1394 | 1391 |
/// |
1395 | 1392 |
/// \param digraph The digraph the algorithm runs on. |
1396 | 1393 |
/// \param visitor The visitor object of the algorithm. |
1397 | 1394 |
BfsVisit(const Digraph& digraph, Visitor& visitor) |
1398 | 1395 |
: _digraph(&digraph), _visitor(&visitor), |
1399 | 1396 |
_reached(0), local_reached(false) {} |
1400 | 1397 |
|
1401 | 1398 |
/// \brief Destructor. |
1402 | 1399 |
~BfsVisit() { |
1403 | 1400 |
if(local_reached) delete _reached; |
1404 | 1401 |
} |
1405 | 1402 |
|
1406 | 1403 |
/// \brief Sets the map that indicates which nodes are reached. |
1407 | 1404 |
/// |
1408 | 1405 |
/// Sets the map that indicates which nodes are reached. |
1409 | 1406 |
/// If you don't use this function before calling \ref run(Node) "run()" |
1410 | 1407 |
/// or \ref init(), an instance will be allocated automatically. |
1411 | 1408 |
/// The destructor deallocates this automatically allocated map, |
1412 | 1409 |
/// of course. |
1413 | 1410 |
/// \return <tt> (*this) </tt> |
1414 | 1411 |
BfsVisit &reachedMap(ReachedMap &m) { |
1415 | 1412 |
if(local_reached) { |
1416 | 1413 |
delete _reached; |
1417 | 1414 |
local_reached = false; |
1418 | 1415 |
} |
1419 | 1416 |
_reached = &m; |
1420 | 1417 |
return *this; |
1421 | 1418 |
} |
1422 | 1419 |
|
1423 | 1420 |
public: |
1424 | 1421 |
|
1425 | 1422 |
/// \name Execution Control |
1426 | 1423 |
/// The simplest way to execute the BFS algorithm is to use one of the |
1427 | 1424 |
/// member functions called \ref run(Node) "run()".\n |
1428 |
/// If you need more control on the execution, first you have to call |
|
1429 |
/// \ref init(), then you can add several source nodes with |
|
1425 |
/// If you need better control on the execution, you have to call |
|
1426 |
/// \ref init() first, then you can add several source nodes with |
|
1430 | 1427 |
/// \ref addSource(). Finally the actual path computation can be |
1431 | 1428 |
/// performed with one of the \ref start() functions. |
1432 | 1429 |
|
1433 | 1430 |
/// @{ |
1434 | 1431 |
|
1435 | 1432 |
/// \brief Initializes the internal data structures. |
1436 | 1433 |
/// |
1437 | 1434 |
/// Initializes the internal data structures. |
1438 | 1435 |
void init() { |
1439 | 1436 |
create_maps(); |
1440 | 1437 |
_list.resize(countNodes(*_digraph)); |
1441 | 1438 |
_list_front = _list_back = -1; |
1442 | 1439 |
for (NodeIt u(*_digraph) ; u != INVALID ; ++u) { |
1443 | 1440 |
_reached->set(u, false); |
1444 | 1441 |
} |
1445 | 1442 |
} |
1446 | 1443 |
|
1447 | 1444 |
/// \brief Adds a new source node. |
1448 | 1445 |
/// |
1449 | 1446 |
/// Adds a new source node to the set of nodes to be processed. |
1450 | 1447 |
void addSource(Node s) { |
1451 | 1448 |
if(!(*_reached)[s]) { |
1452 | 1449 |
_reached->set(s,true); |
1453 | 1450 |
_visitor->start(s); |
1454 | 1451 |
_visitor->reach(s); |
1455 | 1452 |
_list[++_list_back] = s; |
1456 | 1453 |
} |
1457 | 1454 |
} |
1458 | 1455 |
|
1459 | 1456 |
/// \brief Processes the next node. |
1460 | 1457 |
/// |
1461 | 1458 |
/// Processes the next node. |
1462 | 1459 |
/// |
1463 | 1460 |
/// \return The processed node. |
1464 | 1461 |
/// |
1465 | 1462 |
/// \pre The queue must not be empty. |
1466 | 1463 |
Node processNextNode() { |
1467 | 1464 |
Node n = _list[++_list_front]; |
1468 | 1465 |
_visitor->process(n); |
1469 | 1466 |
Arc e; |
1470 | 1467 |
for (_digraph->firstOut(e, n); e != INVALID; _digraph->nextOut(e)) { |
1471 | 1468 |
Node m = _digraph->target(e); |
1472 | 1469 |
if (!(*_reached)[m]) { |
1473 | 1470 |
_visitor->discover(e); |
1474 | 1471 |
_visitor->reach(m); |
1475 | 1472 |
_reached->set(m, true); |
1476 | 1473 |
_list[++_list_back] = m; |
1477 | 1474 |
} else { |
1478 | 1475 |
_visitor->examine(e); |
1479 | 1476 |
} |
1480 | 1477 |
} |
1481 | 1478 |
return n; |
1482 | 1479 |
} |
1483 | 1480 |
|
1484 | 1481 |
/// \brief Processes the next node. |
1485 | 1482 |
/// |
1486 | 1483 |
/// Processes the next node and checks if the given target node |
1487 | 1484 |
/// is reached. If the target node is reachable from the processed |
1488 | 1485 |
/// node, then the \c reach parameter will be set to \c true. |
1489 | 1486 |
/// |
1490 | 1487 |
/// \param target The target node. |
1491 | 1488 |
/// \retval reach Indicates if the target node is reached. |
1492 | 1489 |
/// It should be initially \c false. |
1493 | 1490 |
/// |
1494 | 1491 |
/// \return The processed node. |
1495 | 1492 |
/// |
1496 | 1493 |
/// \pre The queue must not be empty. |
1497 | 1494 |
Node processNextNode(Node target, bool& reach) { |
1498 | 1495 |
Node n = _list[++_list_front]; |
1499 | 1496 |
_visitor->process(n); |
1500 | 1497 |
Arc e; |
1501 | 1498 |
for (_digraph->firstOut(e, n); e != INVALID; _digraph->nextOut(e)) { |
1502 | 1499 |
Node m = _digraph->target(e); |
1503 | 1500 |
if (!(*_reached)[m]) { |
1504 | 1501 |
_visitor->discover(e); |
1505 | 1502 |
_visitor->reach(m); |
1506 | 1503 |
_reached->set(m, true); |
1507 | 1504 |
_list[++_list_back] = m; |
1508 | 1505 |
reach = reach || (target == m); |
1509 | 1506 |
} else { |
1510 | 1507 |
_visitor->examine(e); |
1511 | 1508 |
} |
1512 | 1509 |
} |
1513 | 1510 |
return n; |
1514 | 1511 |
} |
1515 | 1512 |
|
1516 | 1513 |
/// \brief Processes the next node. |
1517 | 1514 |
/// |
1518 | 1515 |
/// Processes the next node and checks if at least one of reached |
1519 | 1516 |
/// nodes has \c true value in the \c nm node map. If one node |
1520 | 1517 |
/// with \c true value is reachable from the processed node, then the |
1521 | 1518 |
/// \c rnode parameter will be set to the first of such nodes. |
1522 | 1519 |
/// |
1523 | 1520 |
/// \param nm A \c bool (or convertible) node map that indicates the |
1524 | 1521 |
/// possible targets. |
1525 | 1522 |
/// \retval rnode The reached target node. |
1526 | 1523 |
/// It should be initially \c INVALID. |
1527 | 1524 |
/// |
1528 | 1525 |
/// \return The processed node. |
1529 | 1526 |
/// |
1530 | 1527 |
/// \pre The queue must not be empty. |
1531 | 1528 |
template <typename NM> |
1532 | 1529 |
Node processNextNode(const NM& nm, Node& rnode) { |
1533 | 1530 |
Node n = _list[++_list_front]; |
1534 | 1531 |
_visitor->process(n); |
1535 | 1532 |
Arc e; |
1536 | 1533 |
for (_digraph->firstOut(e, n); e != INVALID; _digraph->nextOut(e)) { |
1537 | 1534 |
Node m = _digraph->target(e); |
1538 | 1535 |
if (!(*_reached)[m]) { |
1539 | 1536 |
_visitor->discover(e); |
1540 | 1537 |
_visitor->reach(m); |
1541 | 1538 |
_reached->set(m, true); |
1542 | 1539 |
_list[++_list_back] = m; |
1543 | 1540 |
if (nm[m] && rnode == INVALID) rnode = m; |
1544 | 1541 |
} else { |
1545 | 1542 |
_visitor->examine(e); |
1546 | 1543 |
} |
1547 | 1544 |
} |
1548 | 1545 |
return n; |
1549 | 1546 |
} |
1550 | 1547 |
|
1551 | 1548 |
/// \brief The next node to be processed. |
1552 | 1549 |
/// |
1553 | 1550 |
/// Returns the next node to be processed or \c INVALID if the queue |
1554 | 1551 |
/// is empty. |
1555 | 1552 |
Node nextNode() const { |
1556 | 1553 |
return _list_front != _list_back ? _list[_list_front + 1] : INVALID; |
1557 | 1554 |
} |
1558 | 1555 |
|
1559 | 1556 |
/// \brief Returns \c false if there are nodes |
1560 | 1557 |
/// to be processed. |
1561 | 1558 |
/// |
1562 | 1559 |
/// Returns \c false if there are nodes |
1563 | 1560 |
/// to be processed in the queue. |
1564 | 1561 |
bool emptyQueue() const { return _list_front == _list_back; } |
1565 | 1562 |
|
1566 | 1563 |
/// \brief Returns the number of the nodes to be processed. |
1567 | 1564 |
/// |
1568 | 1565 |
/// Returns the number of the nodes to be processed in the queue. |
1569 | 1566 |
int queueSize() const { return _list_back - _list_front; } |
1570 | 1567 |
|
1571 | 1568 |
/// \brief Executes the algorithm. |
1572 | 1569 |
/// |
1573 | 1570 |
/// Executes the algorithm. |
1574 | 1571 |
/// |
1575 | 1572 |
/// This method runs the %BFS algorithm from the root node(s) |
1576 | 1573 |
/// in order to compute the shortest path to each node. |
1577 | 1574 |
/// |
1578 | 1575 |
/// The algorithm computes |
1579 | 1576 |
/// - the shortest path tree (forest), |
1580 | 1577 |
/// - the distance of each node from the root(s). |
1581 | 1578 |
/// |
1582 | 1579 |
/// \pre init() must be called and at least one root node should be added |
1583 | 1580 |
/// with addSource() before using this function. |
1584 | 1581 |
/// |
1585 | 1582 |
/// \note <tt>b.start()</tt> is just a shortcut of the following code. |
1586 | 1583 |
/// \code |
1587 | 1584 |
/// while ( !b.emptyQueue() ) { |
1588 | 1585 |
/// b.processNextNode(); |
1589 | 1586 |
/// } |
1590 | 1587 |
/// \endcode |
1591 | 1588 |
void start() { |
1592 | 1589 |
while ( !emptyQueue() ) processNextNode(); |
1593 | 1590 |
} |
1594 | 1591 |
|
1595 | 1592 |
/// \brief Executes the algorithm until the given target node is reached. |
1596 | 1593 |
/// |
1597 | 1594 |
/// Executes the algorithm until the given target node is reached. |
1598 | 1595 |
/// |
1599 | 1596 |
/// This method runs the %BFS algorithm from the root node(s) |
1600 | 1597 |
/// in order to compute the shortest path to \c t. |
1601 | 1598 |
/// |
1602 | 1599 |
/// The algorithm computes |
1603 | 1600 |
/// - the shortest path to \c t, |
1604 | 1601 |
/// - the distance of \c t from the root(s). |
1605 | 1602 |
/// |
1606 | 1603 |
/// \pre init() must be called and at least one root node should be |
1607 | 1604 |
/// added with addSource() before using this function. |
1608 | 1605 |
/// |
1609 | 1606 |
/// \note <tt>b.start(t)</tt> is just a shortcut of the following code. |
1610 | 1607 |
/// \code |
1611 | 1608 |
/// bool reach = false; |
1612 | 1609 |
/// while ( !b.emptyQueue() && !reach ) { |
1613 | 1610 |
/// b.processNextNode(t, reach); |
1614 | 1611 |
/// } |
1615 | 1612 |
/// \endcode |
1616 | 1613 |
void start(Node t) { |
1617 | 1614 |
bool reach = false; |
1618 | 1615 |
while ( !emptyQueue() && !reach ) processNextNode(t, reach); |
1619 | 1616 |
} |
1620 | 1617 |
|
1621 | 1618 |
/// \brief Executes the algorithm until a condition is met. |
1622 | 1619 |
/// |
1623 | 1620 |
/// Executes the algorithm until a condition is met. |
1624 | 1621 |
/// |
1625 | 1622 |
/// This method runs the %BFS algorithm from the root node(s) in |
1626 | 1623 |
/// order to compute the shortest path to a node \c v with |
1627 | 1624 |
/// <tt>nm[v]</tt> true, if such a node can be found. |
1628 | 1625 |
/// |
1629 | 1626 |
/// \param nm must be a bool (or convertible) node map. The |
1630 | 1627 |
/// algorithm will stop when it reaches a node \c v with |
1631 | 1628 |
/// <tt>nm[v]</tt> true. |
1632 | 1629 |
/// |
1633 | 1630 |
/// \return The reached node \c v with <tt>nm[v]</tt> true or |
1634 | 1631 |
/// \c INVALID if no such node was found. |
1635 | 1632 |
/// |
1636 | 1633 |
/// \pre init() must be called and at least one root node should be |
1637 | 1634 |
/// added with addSource() before using this function. |
1638 | 1635 |
/// |
1639 | 1636 |
/// \note <tt>b.start(nm)</tt> is just a shortcut of the following code. |
1640 | 1637 |
/// \code |
1641 | 1638 |
/// Node rnode = INVALID; |
1642 | 1639 |
/// while ( !b.emptyQueue() && rnode == INVALID ) { |
1643 | 1640 |
/// b.processNextNode(nm, rnode); |
1644 | 1641 |
/// } |
1645 | 1642 |
/// return rnode; |
1646 | 1643 |
/// \endcode |
1647 | 1644 |
template <typename NM> |
1648 | 1645 |
Node start(const NM &nm) { |
1649 | 1646 |
Node rnode = INVALID; |
1650 | 1647 |
while ( !emptyQueue() && rnode == INVALID ) { |
1651 | 1648 |
processNextNode(nm, rnode); |
1652 | 1649 |
} |
1653 | 1650 |
return rnode; |
1654 | 1651 |
} |
1655 | 1652 |
|
1656 | 1653 |
/// \brief Runs the algorithm from the given source node. |
1657 | 1654 |
/// |
1658 | 1655 |
/// This method runs the %BFS algorithm from node \c s |
1659 | 1656 |
/// in order to compute the shortest path to each node. |
1660 | 1657 |
/// |
1661 | 1658 |
/// The algorithm computes |
1662 | 1659 |
/// - the shortest path tree, |
1663 | 1660 |
/// - the distance of each node from the root. |
1664 | 1661 |
/// |
1665 | 1662 |
/// \note <tt>b.run(s)</tt> is just a shortcut of the following code. |
1666 | 1663 |
///\code |
1667 | 1664 |
/// b.init(); |
1668 | 1665 |
/// b.addSource(s); |
1669 | 1666 |
/// b.start(); |
1670 | 1667 |
///\endcode |
1671 | 1668 |
void run(Node s) { |
1672 | 1669 |
init(); |
1673 | 1670 |
addSource(s); |
1674 | 1671 |
start(); |
1675 | 1672 |
} |
1676 | 1673 |
|
1677 | 1674 |
/// \brief Finds the shortest path between \c s and \c t. |
1678 | 1675 |
/// |
1679 | 1676 |
/// This method runs the %BFS algorithm from node \c s |
1680 | 1677 |
/// in order to compute the shortest path to node \c t |
1681 | 1678 |
/// (it stops searching when \c t is processed). |
1682 | 1679 |
/// |
1683 | 1680 |
/// \return \c true if \c t is reachable form \c s. |
1684 | 1681 |
/// |
1685 | 1682 |
/// \note Apart from the return value, <tt>b.run(s,t)</tt> is just a |
1686 | 1683 |
/// shortcut of the following code. |
1687 | 1684 |
///\code |
1688 | 1685 |
/// b.init(); |
1689 | 1686 |
/// b.addSource(s); |
1690 | 1687 |
/// b.start(t); |
1691 | 1688 |
///\endcode |
1692 | 1689 |
bool run(Node s,Node t) { |
1693 | 1690 |
init(); |
1694 | 1691 |
addSource(s); |
1695 | 1692 |
start(t); |
1696 | 1693 |
return reached(t); |
1697 | 1694 |
} |
1698 | 1695 |
|
1699 | 1696 |
/// \brief Runs the algorithm to visit all nodes in the digraph. |
1700 | 1697 |
/// |
1701 | 1698 |
/// This method runs the %BFS algorithm in order to |
1702 | 1699 |
/// compute the shortest path to each node. |
1703 | 1700 |
/// |
1704 | 1701 |
/// The algorithm computes |
1705 | 1702 |
/// - the shortest path tree (forest), |
1706 | 1703 |
/// - the distance of each node from the root(s). |
1707 | 1704 |
/// |
1708 | 1705 |
/// \note <tt>b.run(s)</tt> is just a shortcut of the following code. |
1709 | 1706 |
///\code |
1710 | 1707 |
/// b.init(); |
1711 | 1708 |
/// for (NodeIt n(gr); n != INVALID; ++n) { |
1712 | 1709 |
/// if (!b.reached(n)) { |
1713 | 1710 |
/// b.addSource(n); |
1714 | 1711 |
/// b.start(); |
1715 | 1712 |
/// } |
1716 | 1713 |
/// } |
1717 | 1714 |
///\endcode |
1718 | 1715 |
void run() { |
1719 | 1716 |
init(); |
1720 | 1717 |
for (NodeIt it(*_digraph); it != INVALID; ++it) { |
1721 | 1718 |
if (!reached(it)) { |
1722 | 1719 |
addSource(it); |
1723 | 1720 |
start(); |
1724 | 1721 |
} |
1725 | 1722 |
} |
1726 | 1723 |
} |
1727 | 1724 |
|
1728 | 1725 |
///@} |
1729 | 1726 |
|
1730 | 1727 |
/// \name Query Functions |
1731 | 1728 |
/// The results of the BFS algorithm can be obtained using these |
1732 | 1729 |
/// functions.\n |
1733 | 1730 |
/// Either \ref run(Node) "run()" or \ref start() should be called |
1734 | 1731 |
/// before using them. |
1735 | 1732 |
|
1736 | 1733 |
///@{ |
1737 | 1734 |
|
1738 |
/// \brief Checks if |
|
1735 |
/// \brief Checks if the given node is reached from the root(s). |
|
1739 | 1736 |
/// |
1740 | 1737 |
/// Returns \c true if \c v is reached from the root(s). |
1741 | 1738 |
/// |
1742 | 1739 |
/// \pre Either \ref run(Node) "run()" or \ref init() |
1743 | 1740 |
/// must be called before using this function. |
1744 | 1741 |
bool reached(Node v) const { return (*_reached)[v]; } |
1745 | 1742 |
|
1746 | 1743 |
///@} |
1747 | 1744 |
|
1748 | 1745 |
}; |
1749 | 1746 |
|
1750 | 1747 |
} //END OF NAMESPACE LEMON |
1751 | 1748 |
|
1752 | 1749 |
#endif |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_BITS_MAP_EXTENDER_H |
20 | 20 |
#define LEMON_BITS_MAP_EXTENDER_H |
21 | 21 |
|
22 | 22 |
#include <iterator> |
23 | 23 |
|
24 | 24 |
#include <lemon/bits/traits.h> |
25 | 25 |
|
26 | 26 |
#include <lemon/concept_check.h> |
27 | 27 |
#include <lemon/concepts/maps.h> |
28 | 28 |
|
29 | 29 |
//\file |
30 | 30 |
//\brief Extenders for iterable maps. |
31 | 31 |
|
32 | 32 |
namespace lemon { |
33 | 33 |
|
34 | 34 |
// \ingroup graphbits |
35 | 35 |
// |
36 | 36 |
// \brief Extender for maps |
37 | 37 |
template <typename _Map> |
38 | 38 |
class MapExtender : public _Map { |
39 | 39 |
typedef _Map Parent; |
40 | 40 |
typedef typename Parent::GraphType GraphType; |
41 | 41 |
|
42 | 42 |
public: |
43 | 43 |
|
44 | 44 |
typedef MapExtender Map; |
45 | 45 |
typedef typename Parent::Key Item; |
46 | 46 |
|
47 | 47 |
typedef typename Parent::Key Key; |
48 | 48 |
typedef typename Parent::Value Value; |
49 | 49 |
typedef typename Parent::Reference Reference; |
50 | 50 |
typedef typename Parent::ConstReference ConstReference; |
51 | 51 |
|
52 |
typedef typename Parent::ReferenceMapTag ReferenceMapTag; |
|
53 |
|
|
52 | 54 |
class MapIt; |
53 | 55 |
class ConstMapIt; |
54 | 56 |
|
55 | 57 |
friend class MapIt; |
56 | 58 |
friend class ConstMapIt; |
57 | 59 |
|
58 | 60 |
public: |
59 | 61 |
|
60 | 62 |
MapExtender(const GraphType& graph) |
61 | 63 |
: Parent(graph) {} |
62 | 64 |
|
63 | 65 |
MapExtender(const GraphType& graph, const Value& value) |
64 | 66 |
: Parent(graph, value) {} |
65 | 67 |
|
66 | 68 |
private: |
67 | 69 |
MapExtender& operator=(const MapExtender& cmap) { |
68 | 70 |
return operator=<MapExtender>(cmap); |
69 | 71 |
} |
70 | 72 |
|
71 | 73 |
template <typename CMap> |
72 | 74 |
MapExtender& operator=(const CMap& cmap) { |
73 | 75 |
Parent::operator=(cmap); |
74 | 76 |
return *this; |
75 | 77 |
} |
76 | 78 |
|
77 | 79 |
public: |
78 | 80 |
class MapIt : public Item { |
79 | 81 |
typedef Item Parent; |
80 | 82 |
|
81 | 83 |
public: |
82 | 84 |
|
83 | 85 |
typedef typename Map::Value Value; |
84 | 86 |
|
85 | 87 |
MapIt() {} |
86 | 88 |
|
87 | 89 |
MapIt(Invalid i) : Parent(i) { } |
88 | 90 |
|
89 | 91 |
explicit MapIt(Map& _map) : map(_map) { |
90 | 92 |
map.notifier()->first(*this); |
91 | 93 |
} |
92 | 94 |
|
93 | 95 |
MapIt(const Map& _map, const Item& item) |
94 | 96 |
: Parent(item), map(_map) {} |
95 | 97 |
|
96 | 98 |
MapIt& operator++() { |
97 | 99 |
map.notifier()->next(*this); |
98 | 100 |
return *this; |
99 | 101 |
} |
100 | 102 |
|
101 | 103 |
typename MapTraits<Map>::ConstReturnValue operator*() const { |
102 | 104 |
return map[*this]; |
103 | 105 |
} |
104 | 106 |
|
105 | 107 |
typename MapTraits<Map>::ReturnValue operator*() { |
106 | 108 |
return map[*this]; |
107 | 109 |
} |
108 | 110 |
|
109 | 111 |
void set(const Value& value) { |
110 | 112 |
map.set(*this, value); |
111 | 113 |
} |
112 | 114 |
|
113 | 115 |
protected: |
114 | 116 |
Map& map; |
115 | 117 |
|
116 | 118 |
}; |
117 | 119 |
|
118 | 120 |
class ConstMapIt : public Item { |
119 | 121 |
typedef Item Parent; |
120 | 122 |
|
121 | 123 |
public: |
122 | 124 |
|
123 | 125 |
typedef typename Map::Value Value; |
124 | 126 |
|
125 | 127 |
ConstMapIt() {} |
126 | 128 |
|
127 | 129 |
ConstMapIt(Invalid i) : Parent(i) { } |
128 | 130 |
|
129 | 131 |
explicit ConstMapIt(Map& _map) : map(_map) { |
130 | 132 |
map.notifier()->first(*this); |
131 | 133 |
} |
132 | 134 |
|
133 | 135 |
ConstMapIt(const Map& _map, const Item& item) |
134 | 136 |
: Parent(item), map(_map) {} |
135 | 137 |
|
136 | 138 |
ConstMapIt& operator++() { |
137 | 139 |
map.notifier()->next(*this); |
138 | 140 |
return *this; |
139 | 141 |
} |
140 | 142 |
|
141 | 143 |
typename MapTraits<Map>::ConstReturnValue operator*() const { |
142 | 144 |
return map[*this]; |
143 | 145 |
} |
144 | 146 |
|
145 | 147 |
protected: |
146 | 148 |
const Map& map; |
147 | 149 |
}; |
148 | 150 |
|
149 | 151 |
class ItemIt : public Item { |
150 | 152 |
typedef Item Parent; |
151 | 153 |
|
152 | 154 |
public: |
153 | 155 |
|
154 | 156 |
ItemIt() {} |
155 | 157 |
|
156 | 158 |
ItemIt(Invalid i) : Parent(i) { } |
157 | 159 |
|
158 | 160 |
explicit ItemIt(Map& _map) : map(_map) { |
159 | 161 |
map.notifier()->first(*this); |
160 | 162 |
} |
161 | 163 |
|
162 | 164 |
ItemIt(const Map& _map, const Item& item) |
163 | 165 |
: Parent(item), map(_map) {} |
164 | 166 |
|
165 | 167 |
ItemIt& operator++() { |
166 | 168 |
map.notifier()->next(*this); |
167 | 169 |
return *this; |
168 | 170 |
} |
169 | 171 |
|
170 | 172 |
protected: |
171 | 173 |
const Map& map; |
172 | 174 |
|
173 | 175 |
}; |
174 | 176 |
}; |
175 | 177 |
|
176 | 178 |
// \ingroup graphbits |
177 | 179 |
// |
178 | 180 |
// \brief Extender for maps which use a subset of the items. |
179 | 181 |
template <typename _Graph, typename _Map> |
180 | 182 |
class SubMapExtender : public _Map { |
181 | 183 |
typedef _Map Parent; |
182 | 184 |
typedef _Graph GraphType; |
183 | 185 |
|
184 | 186 |
public: |
185 | 187 |
|
186 | 188 |
typedef SubMapExtender Map; |
187 | 189 |
typedef typename Parent::Key Item; |
188 | 190 |
|
189 | 191 |
typedef typename Parent::Key Key; |
190 | 192 |
typedef typename Parent::Value Value; |
191 | 193 |
typedef typename Parent::Reference Reference; |
192 | 194 |
typedef typename Parent::ConstReference ConstReference; |
193 | 195 |
|
196 |
typedef typename Parent::ReferenceMapTag ReferenceMapTag; |
|
197 |
|
|
194 | 198 |
class MapIt; |
195 | 199 |
class ConstMapIt; |
196 | 200 |
|
197 | 201 |
friend class MapIt; |
198 | 202 |
friend class ConstMapIt; |
199 | 203 |
|
200 | 204 |
public: |
201 | 205 |
|
202 | 206 |
SubMapExtender(const GraphType& _graph) |
203 | 207 |
: Parent(_graph), graph(_graph) {} |
204 | 208 |
|
205 | 209 |
SubMapExtender(const GraphType& _graph, const Value& _value) |
206 | 210 |
: Parent(_graph, _value), graph(_graph) {} |
207 | 211 |
|
208 | 212 |
private: |
209 | 213 |
SubMapExtender& operator=(const SubMapExtender& cmap) { |
210 | 214 |
return operator=<MapExtender>(cmap); |
211 | 215 |
} |
212 | 216 |
|
213 | 217 |
template <typename CMap> |
214 | 218 |
SubMapExtender& operator=(const CMap& cmap) { |
215 | 219 |
checkConcept<concepts::ReadMap<Key, Value>, CMap>(); |
216 | 220 |
Item it; |
217 | 221 |
for (graph.first(it); it != INVALID; graph.next(it)) { |
218 | 222 |
Parent::set(it, cmap[it]); |
219 | 223 |
} |
220 | 224 |
return *this; |
221 | 225 |
} |
222 | 226 |
|
223 | 227 |
public: |
224 | 228 |
class MapIt : public Item { |
225 | 229 |
typedef Item Parent; |
226 | 230 |
|
227 | 231 |
public: |
228 | 232 |
typedef typename Map::Value Value; |
229 | 233 |
|
230 | 234 |
MapIt() {} |
231 | 235 |
|
232 | 236 |
MapIt(Invalid i) : Parent(i) { } |
233 | 237 |
|
234 | 238 |
explicit MapIt(Map& _map) : map(_map) { |
235 | 239 |
map.graph.first(*this); |
236 | 240 |
} |
237 | 241 |
|
238 | 242 |
MapIt(const Map& _map, const Item& item) |
239 | 243 |
: Parent(item), map(_map) {} |
240 | 244 |
|
241 | 245 |
MapIt& operator++() { |
242 | 246 |
map.graph.next(*this); |
243 | 247 |
return *this; |
244 | 248 |
} |
245 | 249 |
|
246 | 250 |
typename MapTraits<Map>::ConstReturnValue operator*() const { |
247 | 251 |
return map[*this]; |
248 | 252 |
} |
249 | 253 |
|
250 | 254 |
typename MapTraits<Map>::ReturnValue operator*() { |
251 | 255 |
return map[*this]; |
252 | 256 |
} |
253 | 257 |
|
254 | 258 |
void set(const Value& value) { |
255 | 259 |
map.set(*this, value); |
256 | 260 |
} |
257 | 261 |
|
258 | 262 |
protected: |
259 | 263 |
Map& map; |
260 | 264 |
|
261 | 265 |
}; |
262 | 266 |
|
263 | 267 |
class ConstMapIt : public Item { |
264 | 268 |
typedef Item Parent; |
265 | 269 |
|
266 | 270 |
public: |
267 | 271 |
|
268 | 272 |
typedef typename Map::Value Value; |
269 | 273 |
|
270 | 274 |
ConstMapIt() {} |
271 | 275 |
|
272 | 276 |
ConstMapIt(Invalid i) : Parent(i) { } |
273 | 277 |
|
274 | 278 |
explicit ConstMapIt(Map& _map) : map(_map) { |
275 | 279 |
map.graph.first(*this); |
276 | 280 |
} |
277 | 281 |
|
278 | 282 |
ConstMapIt(const Map& _map, const Item& item) |
279 | 283 |
: Parent(item), map(_map) {} |
280 | 284 |
|
281 | 285 |
ConstMapIt& operator++() { |
282 | 286 |
map.graph.next(*this); |
283 | 287 |
return *this; |
284 | 288 |
} |
285 | 289 |
|
286 | 290 |
typename MapTraits<Map>::ConstReturnValue operator*() const { |
287 | 291 |
return map[*this]; |
288 | 292 |
} |
289 | 293 |
|
290 | 294 |
protected: |
291 | 295 |
const Map& map; |
292 | 296 |
}; |
293 | 297 |
|
294 | 298 |
class ItemIt : public Item { |
295 | 299 |
typedef Item Parent; |
296 | 300 |
|
297 | 301 |
public: |
298 | 302 |
|
299 | 303 |
ItemIt() {} |
300 | 304 |
|
301 | 305 |
ItemIt(Invalid i) : Parent(i) { } |
302 | 306 |
|
303 | 307 |
explicit ItemIt(Map& _map) : map(_map) { |
304 | 308 |
map.graph.first(*this); |
305 | 309 |
} |
306 | 310 |
|
307 | 311 |
ItemIt(const Map& _map, const Item& item) |
308 | 312 |
: Parent(item), map(_map) {} |
309 | 313 |
|
310 | 314 |
ItemIt& operator++() { |
311 | 315 |
map.graph.next(*this); |
312 | 316 |
return *this; |
313 | 317 |
} |
314 | 318 |
|
315 | 319 |
protected: |
316 | 320 |
const Map& map; |
317 | 321 |
|
318 | 322 |
}; |
319 | 323 |
|
320 | 324 |
private: |
321 | 325 |
|
322 | 326 |
const GraphType& graph; |
323 | 327 |
|
324 | 328 |
}; |
325 | 329 |
|
326 | 330 |
} |
327 | 331 |
|
328 | 332 |
#endif |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_CIRCULATION_H |
20 | 20 |
#define LEMON_CIRCULATION_H |
21 | 21 |
|
22 | 22 |
#include <lemon/tolerance.h> |
23 | 23 |
#include <lemon/elevator.h> |
24 | 24 |
#include <limits> |
25 | 25 |
|
26 | 26 |
///\ingroup max_flow |
27 | 27 |
///\file |
28 | 28 |
///\brief Push-relabel algorithm for finding a feasible circulation. |
29 | 29 |
/// |
30 | 30 |
namespace lemon { |
31 | 31 |
|
32 | 32 |
/// \brief Default traits class of Circulation class. |
33 | 33 |
/// |
34 | 34 |
/// Default traits class of Circulation class. |
35 | 35 |
/// |
36 | 36 |
/// \tparam GR Type of the digraph the algorithm runs on. |
37 | 37 |
/// \tparam LM The type of the lower bound map. |
38 | 38 |
/// \tparam UM The type of the upper bound (capacity) map. |
39 | 39 |
/// \tparam SM The type of the supply map. |
40 | 40 |
template <typename GR, typename LM, |
41 | 41 |
typename UM, typename SM> |
42 | 42 |
struct CirculationDefaultTraits { |
43 | 43 |
|
44 | 44 |
/// \brief The type of the digraph the algorithm runs on. |
45 | 45 |
typedef GR Digraph; |
46 | 46 |
|
47 | 47 |
/// \brief The type of the lower bound map. |
48 | 48 |
/// |
49 | 49 |
/// The type of the map that stores the lower bounds on the arcs. |
50 | 50 |
/// It must conform to the \ref concepts::ReadMap "ReadMap" concept. |
51 | 51 |
typedef LM LowerMap; |
52 | 52 |
|
53 | 53 |
/// \brief The type of the upper bound (capacity) map. |
54 | 54 |
/// |
55 | 55 |
/// The type of the map that stores the upper bounds (capacities) |
56 | 56 |
/// on the arcs. |
57 | 57 |
/// It must conform to the \ref concepts::ReadMap "ReadMap" concept. |
58 | 58 |
typedef UM UpperMap; |
59 | 59 |
|
60 | 60 |
/// \brief The type of supply map. |
61 | 61 |
/// |
62 | 62 |
/// The type of the map that stores the signed supply values of the |
63 | 63 |
/// nodes. |
64 | 64 |
/// It must conform to the \ref concepts::ReadMap "ReadMap" concept. |
65 | 65 |
typedef SM SupplyMap; |
66 | 66 |
|
67 | 67 |
/// \brief The type of the flow and supply values. |
68 | 68 |
typedef typename SupplyMap::Value Value; |
69 | 69 |
|
70 | 70 |
/// \brief The type of the map that stores the flow values. |
71 | 71 |
/// |
72 | 72 |
/// The type of the map that stores the flow values. |
73 | 73 |
/// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" |
74 | 74 |
/// concept. |
75 |
#ifdef DOXYGEN |
|
76 |
typedef GR::ArcMap<Value> FlowMap; |
|
77 |
#else |
|
75 | 78 |
typedef typename Digraph::template ArcMap<Value> FlowMap; |
79 |
#endif |
|
76 | 80 |
|
77 | 81 |
/// \brief Instantiates a FlowMap. |
78 | 82 |
/// |
79 | 83 |
/// This function instantiates a \ref FlowMap. |
80 | 84 |
/// \param digraph The digraph for which we would like to define |
81 | 85 |
/// the flow map. |
82 | 86 |
static FlowMap* createFlowMap(const Digraph& digraph) { |
83 | 87 |
return new FlowMap(digraph); |
84 | 88 |
} |
85 | 89 |
|
86 | 90 |
/// \brief The elevator type used by the algorithm. |
87 | 91 |
/// |
88 | 92 |
/// The elevator type used by the algorithm. |
89 | 93 |
/// |
90 |
/// \sa Elevator |
|
91 |
/// \sa LinkedElevator |
|
94 |
/// \sa Elevator, LinkedElevator |
|
95 |
#ifdef DOXYGEN |
|
96 |
typedef lemon::Elevator<GR, GR::Node> Elevator; |
|
97 |
#else |
|
92 | 98 |
typedef lemon::Elevator<Digraph, typename Digraph::Node> Elevator; |
99 |
#endif |
|
93 | 100 |
|
94 | 101 |
/// \brief Instantiates an Elevator. |
95 | 102 |
/// |
96 | 103 |
/// This function instantiates an \ref Elevator. |
97 | 104 |
/// \param digraph The digraph for which we would like to define |
98 | 105 |
/// the elevator. |
99 | 106 |
/// \param max_level The maximum level of the elevator. |
100 | 107 |
static Elevator* createElevator(const Digraph& digraph, int max_level) { |
101 | 108 |
return new Elevator(digraph, max_level); |
102 | 109 |
} |
103 | 110 |
|
104 | 111 |
/// \brief The tolerance used by the algorithm |
105 | 112 |
/// |
106 | 113 |
/// The tolerance used by the algorithm to handle inexact computation. |
107 | 114 |
typedef lemon::Tolerance<Value> Tolerance; |
108 | 115 |
|
109 | 116 |
}; |
110 | 117 |
|
111 | 118 |
/** |
112 | 119 |
\brief Push-relabel algorithm for the network circulation problem. |
113 | 120 |
|
114 | 121 |
\ingroup max_flow |
115 | 122 |
This class implements a push-relabel algorithm for the \e network |
116 | 123 |
\e circulation problem. |
117 | 124 |
It is to find a feasible circulation when lower and upper bounds |
118 | 125 |
are given for the flow values on the arcs and lower bounds are |
119 | 126 |
given for the difference between the outgoing and incoming flow |
120 | 127 |
at the nodes. |
121 | 128 |
|
122 | 129 |
The exact formulation of this problem is the following. |
123 | 130 |
Let \f$G=(V,A)\f$ be a digraph, \f$lower: A\rightarrow\mathbf{R}\f$ |
124 | 131 |
\f$upper: A\rightarrow\mathbf{R}\cup\{\infty\}\f$ denote the lower and |
125 | 132 |
upper bounds on the arcs, for which \f$lower(uv) \leq upper(uv)\f$ |
126 | 133 |
holds for all \f$uv\in A\f$, and \f$sup: V\rightarrow\mathbf{R}\f$ |
127 | 134 |
denotes the signed supply values of the nodes. |
128 | 135 |
If \f$sup(u)>0\f$, then \f$u\f$ is a supply node with \f$sup(u)\f$ |
129 | 136 |
supply, if \f$sup(u)<0\f$, then \f$u\f$ is a demand node with |
130 | 137 |
\f$-sup(u)\f$ demand. |
131 | 138 |
A feasible circulation is an \f$f: A\rightarrow\mathbf{R}\f$ |
132 | 139 |
solution of the following problem. |
133 | 140 |
|
134 | 141 |
\f[ \sum_{uv\in A} f(uv) - \sum_{vu\in A} f(vu) |
135 | 142 |
\geq sup(u) \quad \forall u\in V, \f] |
136 | 143 |
\f[ lower(uv) \leq f(uv) \leq upper(uv) \quad \forall uv\in A. \f] |
137 | 144 |
|
138 | 145 |
The sum of the supply values, i.e. \f$\sum_{u\in V} sup(u)\f$ must be |
139 | 146 |
zero or negative in order to have a feasible solution (since the sum |
140 | 147 |
of the expressions on the left-hand side of the inequalities is zero). |
141 | 148 |
It means that the total demand must be greater or equal to the total |
142 | 149 |
supply and all the supplies have to be carried out from the supply nodes, |
143 | 150 |
but there could be demands that are not satisfied. |
144 | 151 |
If \f$\sum_{u\in V} sup(u)\f$ is zero, then all the supply/demand |
145 | 152 |
constraints have to be satisfied with equality, i.e. all demands |
146 | 153 |
have to be satisfied and all supplies have to be used. |
147 | 154 |
|
148 | 155 |
If you need the opposite inequalities in the supply/demand constraints |
149 | 156 |
(i.e. the total demand is less than the total supply and all the demands |
150 | 157 |
have to be satisfied while there could be supplies that are not used), |
151 | 158 |
then you could easily transform the problem to the above form by reversing |
152 | 159 |
the direction of the arcs and taking the negative of the supply values |
153 | 160 |
(e.g. using \ref ReverseDigraph and \ref NegMap adaptors). |
154 | 161 |
|
155 | 162 |
This algorithm either calculates a feasible circulation, or provides |
156 | 163 |
a \ref barrier() "barrier", which prooves that a feasible soultion |
157 | 164 |
cannot exist. |
158 | 165 |
|
159 | 166 |
Note that this algorithm also provides a feasible solution for the |
160 | 167 |
\ref min_cost_flow "minimum cost flow problem". |
161 | 168 |
|
162 | 169 |
\tparam GR The type of the digraph the algorithm runs on. |
163 | 170 |
\tparam LM The type of the lower bound map. The default |
164 | 171 |
map type is \ref concepts::Digraph::ArcMap "GR::ArcMap<int>". |
165 | 172 |
\tparam UM The type of the upper bound (capacity) map. |
166 | 173 |
The default map type is \c LM. |
167 | 174 |
\tparam SM The type of the supply map. The default map type is |
168 | 175 |
\ref concepts::Digraph::NodeMap "GR::NodeMap<UM::Value>". |
169 | 176 |
*/ |
170 | 177 |
#ifdef DOXYGEN |
171 | 178 |
template< typename GR, |
172 | 179 |
typename LM, |
173 | 180 |
typename UM, |
174 | 181 |
typename SM, |
175 | 182 |
typename TR > |
176 | 183 |
#else |
177 | 184 |
template< typename GR, |
178 | 185 |
typename LM = typename GR::template ArcMap<int>, |
179 | 186 |
typename UM = LM, |
180 | 187 |
typename SM = typename GR::template NodeMap<typename UM::Value>, |
181 | 188 |
typename TR = CirculationDefaultTraits<GR, LM, UM, SM> > |
182 | 189 |
#endif |
183 | 190 |
class Circulation { |
184 | 191 |
public: |
185 | 192 |
|
186 | 193 |
///The \ref CirculationDefaultTraits "traits class" of the algorithm. |
187 | 194 |
typedef TR Traits; |
188 | 195 |
///The type of the digraph the algorithm runs on. |
189 | 196 |
typedef typename Traits::Digraph Digraph; |
190 | 197 |
///The type of the flow and supply values. |
191 | 198 |
typedef typename Traits::Value Value; |
192 | 199 |
|
193 | 200 |
///The type of the lower bound map. |
194 | 201 |
typedef typename Traits::LowerMap LowerMap; |
195 | 202 |
///The type of the upper bound (capacity) map. |
196 | 203 |
typedef typename Traits::UpperMap UpperMap; |
197 | 204 |
///The type of the supply map. |
198 | 205 |
typedef typename Traits::SupplyMap SupplyMap; |
199 | 206 |
///The type of the flow map. |
200 | 207 |
typedef typename Traits::FlowMap FlowMap; |
201 | 208 |
|
202 | 209 |
///The type of the elevator. |
203 | 210 |
typedef typename Traits::Elevator Elevator; |
204 | 211 |
///The type of the tolerance. |
205 | 212 |
typedef typename Traits::Tolerance Tolerance; |
206 | 213 |
|
207 | 214 |
private: |
208 | 215 |
|
209 | 216 |
TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); |
210 | 217 |
|
211 | 218 |
const Digraph &_g; |
212 | 219 |
int _node_num; |
213 | 220 |
|
214 | 221 |
const LowerMap *_lo; |
215 | 222 |
const UpperMap *_up; |
216 | 223 |
const SupplyMap *_supply; |
217 | 224 |
|
218 | 225 |
FlowMap *_flow; |
219 | 226 |
bool _local_flow; |
220 | 227 |
|
221 | 228 |
Elevator* _level; |
222 | 229 |
bool _local_level; |
223 | 230 |
|
224 | 231 |
typedef typename Digraph::template NodeMap<Value> ExcessMap; |
225 | 232 |
ExcessMap* _excess; |
226 | 233 |
|
227 | 234 |
Tolerance _tol; |
228 | 235 |
int _el; |
229 | 236 |
|
230 | 237 |
public: |
231 | 238 |
|
232 | 239 |
typedef Circulation Create; |
233 | 240 |
|
234 | 241 |
///\name Named Template Parameters |
235 | 242 |
|
236 | 243 |
///@{ |
237 | 244 |
|
238 | 245 |
template <typename T> |
239 | 246 |
struct SetFlowMapTraits : public Traits { |
240 | 247 |
typedef T FlowMap; |
241 | 248 |
static FlowMap *createFlowMap(const Digraph&) { |
242 | 249 |
LEMON_ASSERT(false, "FlowMap is not initialized"); |
243 | 250 |
return 0; // ignore warnings |
244 | 251 |
} |
245 | 252 |
}; |
246 | 253 |
|
247 | 254 |
/// \brief \ref named-templ-param "Named parameter" for setting |
248 | 255 |
/// FlowMap type |
249 | 256 |
/// |
250 | 257 |
/// \ref named-templ-param "Named parameter" for setting FlowMap |
251 | 258 |
/// type. |
252 | 259 |
template <typename T> |
253 | 260 |
struct SetFlowMap |
254 | 261 |
: public Circulation<Digraph, LowerMap, UpperMap, SupplyMap, |
255 | 262 |
SetFlowMapTraits<T> > { |
256 | 263 |
typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap, |
257 | 264 |
SetFlowMapTraits<T> > Create; |
258 | 265 |
}; |
259 | 266 |
|
260 | 267 |
template <typename T> |
261 | 268 |
struct SetElevatorTraits : public Traits { |
262 | 269 |
typedef T Elevator; |
263 | 270 |
static Elevator *createElevator(const Digraph&, int) { |
264 | 271 |
LEMON_ASSERT(false, "Elevator is not initialized"); |
265 | 272 |
return 0; // ignore warnings |
266 | 273 |
} |
267 | 274 |
}; |
268 | 275 |
|
269 | 276 |
/// \brief \ref named-templ-param "Named parameter" for setting |
270 | 277 |
/// Elevator type |
271 | 278 |
/// |
272 | 279 |
/// \ref named-templ-param "Named parameter" for setting Elevator |
273 | 280 |
/// type. If this named parameter is used, then an external |
274 | 281 |
/// elevator object must be passed to the algorithm using the |
275 | 282 |
/// \ref elevator(Elevator&) "elevator()" function before calling |
276 | 283 |
/// \ref run() or \ref init(). |
277 | 284 |
/// \sa SetStandardElevator |
278 | 285 |
template <typename T> |
279 | 286 |
struct SetElevator |
280 | 287 |
: public Circulation<Digraph, LowerMap, UpperMap, SupplyMap, |
281 | 288 |
SetElevatorTraits<T> > { |
282 | 289 |
typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap, |
283 | 290 |
SetElevatorTraits<T> > Create; |
284 | 291 |
}; |
285 | 292 |
|
286 | 293 |
template <typename T> |
287 | 294 |
struct SetStandardElevatorTraits : public Traits { |
288 | 295 |
typedef T Elevator; |
289 | 296 |
static Elevator *createElevator(const Digraph& digraph, int max_level) { |
290 | 297 |
return new Elevator(digraph, max_level); |
291 | 298 |
} |
292 | 299 |
}; |
293 | 300 |
|
294 | 301 |
/// \brief \ref named-templ-param "Named parameter" for setting |
295 | 302 |
/// Elevator type with automatic allocation |
296 | 303 |
/// |
297 | 304 |
/// \ref named-templ-param "Named parameter" for setting Elevator |
298 | 305 |
/// type with automatic allocation. |
299 | 306 |
/// The Elevator should have standard constructor interface to be |
300 | 307 |
/// able to automatically created by the algorithm (i.e. the |
301 | 308 |
/// digraph and the maximum level should be passed to it). |
302 | 309 |
/// However an external elevator object could also be passed to the |
303 | 310 |
/// algorithm with the \ref elevator(Elevator&) "elevator()" function |
304 | 311 |
/// before calling \ref run() or \ref init(). |
305 | 312 |
/// \sa SetElevator |
306 | 313 |
template <typename T> |
307 | 314 |
struct SetStandardElevator |
308 | 315 |
: public Circulation<Digraph, LowerMap, UpperMap, SupplyMap, |
309 | 316 |
SetStandardElevatorTraits<T> > { |
310 | 317 |
typedef Circulation<Digraph, LowerMap, UpperMap, SupplyMap, |
311 | 318 |
SetStandardElevatorTraits<T> > Create; |
312 | 319 |
}; |
313 | 320 |
|
314 | 321 |
/// @} |
315 | 322 |
|
316 | 323 |
protected: |
317 | 324 |
|
318 | 325 |
Circulation() {} |
319 | 326 |
|
320 | 327 |
public: |
321 | 328 |
|
322 | 329 |
/// Constructor. |
323 | 330 |
|
324 | 331 |
/// The constructor of the class. |
325 | 332 |
/// |
326 | 333 |
/// \param graph The digraph the algorithm runs on. |
327 | 334 |
/// \param lower The lower bounds for the flow values on the arcs. |
328 | 335 |
/// \param upper The upper bounds (capacities) for the flow values |
329 | 336 |
/// on the arcs. |
330 | 337 |
/// \param supply The signed supply values of the nodes. |
331 | 338 |
Circulation(const Digraph &graph, const LowerMap &lower, |
332 | 339 |
const UpperMap &upper, const SupplyMap &supply) |
333 | 340 |
: _g(graph), _lo(&lower), _up(&upper), _supply(&supply), |
334 | 341 |
_flow(NULL), _local_flow(false), _level(NULL), _local_level(false), |
335 | 342 |
_excess(NULL) {} |
336 | 343 |
|
337 | 344 |
/// Destructor. |
338 | 345 |
~Circulation() { |
339 | 346 |
destroyStructures(); |
340 | 347 |
} |
341 | 348 |
|
342 | 349 |
|
343 | 350 |
private: |
344 | 351 |
|
345 | 352 |
bool checkBoundMaps() { |
346 | 353 |
for (ArcIt e(_g);e!=INVALID;++e) { |
347 | 354 |
if (_tol.less((*_up)[e], (*_lo)[e])) return false; |
348 | 355 |
} |
349 | 356 |
return true; |
350 | 357 |
} |
351 | 358 |
|
352 | 359 |
void createStructures() { |
353 | 360 |
_node_num = _el = countNodes(_g); |
354 | 361 |
|
355 | 362 |
if (!_flow) { |
356 | 363 |
_flow = Traits::createFlowMap(_g); |
357 | 364 |
_local_flow = true; |
358 | 365 |
} |
359 | 366 |
if (!_level) { |
360 | 367 |
_level = Traits::createElevator(_g, _node_num); |
361 | 368 |
_local_level = true; |
362 | 369 |
} |
363 | 370 |
if (!_excess) { |
364 | 371 |
_excess = new ExcessMap(_g); |
365 | 372 |
} |
366 | 373 |
} |
367 | 374 |
|
368 | 375 |
void destroyStructures() { |
369 | 376 |
if (_local_flow) { |
370 | 377 |
delete _flow; |
371 | 378 |
} |
372 | 379 |
if (_local_level) { |
373 | 380 |
delete _level; |
374 | 381 |
} |
375 | 382 |
if (_excess) { |
376 | 383 |
delete _excess; |
377 | 384 |
} |
378 | 385 |
} |
379 | 386 |
|
380 | 387 |
public: |
381 | 388 |
|
382 | 389 |
/// Sets the lower bound map. |
383 | 390 |
|
384 | 391 |
/// Sets the lower bound map. |
385 | 392 |
/// \return <tt>(*this)</tt> |
386 | 393 |
Circulation& lowerMap(const LowerMap& map) { |
387 | 394 |
_lo = ↦ |
388 | 395 |
return *this; |
389 | 396 |
} |
390 | 397 |
|
391 | 398 |
/// Sets the upper bound (capacity) map. |
392 | 399 |
|
393 | 400 |
/// Sets the upper bound (capacity) map. |
394 | 401 |
/// \return <tt>(*this)</tt> |
395 | 402 |
Circulation& upperMap(const UpperMap& map) { |
396 | 403 |
_up = ↦ |
397 | 404 |
return *this; |
398 | 405 |
} |
399 | 406 |
|
400 | 407 |
/// Sets the supply map. |
401 | 408 |
|
402 | 409 |
/// Sets the supply map. |
403 | 410 |
/// \return <tt>(*this)</tt> |
404 | 411 |
Circulation& supplyMap(const SupplyMap& map) { |
405 | 412 |
_supply = ↦ |
406 | 413 |
return *this; |
407 | 414 |
} |
408 | 415 |
|
409 | 416 |
/// \brief Sets the flow map. |
410 | 417 |
/// |
411 | 418 |
/// Sets the flow map. |
412 | 419 |
/// If you don't use this function before calling \ref run() or |
413 | 420 |
/// \ref init(), an instance will be allocated automatically. |
414 | 421 |
/// The destructor deallocates this automatically allocated map, |
415 | 422 |
/// of course. |
416 | 423 |
/// \return <tt>(*this)</tt> |
417 | 424 |
Circulation& flowMap(FlowMap& map) { |
418 | 425 |
if (_local_flow) { |
419 | 426 |
delete _flow; |
420 | 427 |
_local_flow = false; |
421 | 428 |
} |
422 | 429 |
_flow = ↦ |
423 | 430 |
return *this; |
424 | 431 |
} |
425 | 432 |
|
426 | 433 |
/// \brief Sets the elevator used by algorithm. |
427 | 434 |
/// |
428 | 435 |
/// Sets the elevator used by algorithm. |
429 | 436 |
/// If you don't use this function before calling \ref run() or |
430 | 437 |
/// \ref init(), an instance will be allocated automatically. |
431 | 438 |
/// The destructor deallocates this automatically allocated elevator, |
432 | 439 |
/// of course. |
433 | 440 |
/// \return <tt>(*this)</tt> |
434 | 441 |
Circulation& elevator(Elevator& elevator) { |
435 | 442 |
if (_local_level) { |
436 | 443 |
delete _level; |
437 | 444 |
_local_level = false; |
438 | 445 |
} |
439 | 446 |
_level = &elevator; |
440 | 447 |
return *this; |
441 | 448 |
} |
442 | 449 |
|
443 | 450 |
/// \brief Returns a const reference to the elevator. |
444 | 451 |
/// |
445 | 452 |
/// Returns a const reference to the elevator. |
446 | 453 |
/// |
447 | 454 |
/// \pre Either \ref run() or \ref init() must be called before |
448 | 455 |
/// using this function. |
449 | 456 |
const Elevator& elevator() const { |
450 | 457 |
return *_level; |
451 | 458 |
} |
452 | 459 |
|
453 | 460 |
/// \brief Sets the tolerance used by the algorithm. |
454 | 461 |
/// |
455 | 462 |
/// Sets the tolerance object used by the algorithm. |
456 | 463 |
/// \return <tt>(*this)</tt> |
457 | 464 |
Circulation& tolerance(const Tolerance& tolerance) { |
458 | 465 |
_tol = tolerance; |
459 | 466 |
return *this; |
460 | 467 |
} |
461 | 468 |
|
462 | 469 |
/// \brief Returns a const reference to the tolerance. |
463 | 470 |
/// |
464 | 471 |
/// Returns a const reference to the tolerance object used by |
465 | 472 |
/// the algorithm. |
466 | 473 |
const Tolerance& tolerance() const { |
467 | 474 |
return _tol; |
468 | 475 |
} |
469 | 476 |
|
470 | 477 |
/// \name Execution Control |
471 | 478 |
/// The simplest way to execute the algorithm is to call \ref run().\n |
472 |
/// If you need more control on the initial solution or the execution, |
|
473 |
/// first you have to call one of the \ref init() functions, then |
|
479 |
/// If you need better control on the initial solution or the execution, |
|
480 |
/// you have to call one of the \ref init() functions first, then |
|
474 | 481 |
/// the \ref start() function. |
475 | 482 |
|
476 | 483 |
///@{ |
477 | 484 |
|
478 | 485 |
/// Initializes the internal data structures. |
479 | 486 |
|
480 | 487 |
/// Initializes the internal data structures and sets all flow values |
481 | 488 |
/// to the lower bound. |
482 | 489 |
void init() |
483 | 490 |
{ |
484 | 491 |
LEMON_DEBUG(checkBoundMaps(), |
485 | 492 |
"Upper bounds must be greater or equal to the lower bounds"); |
486 | 493 |
|
487 | 494 |
createStructures(); |
488 | 495 |
|
489 | 496 |
for(NodeIt n(_g);n!=INVALID;++n) { |
490 | 497 |
(*_excess)[n] = (*_supply)[n]; |
491 | 498 |
} |
492 | 499 |
|
493 | 500 |
for (ArcIt e(_g);e!=INVALID;++e) { |
494 | 501 |
_flow->set(e, (*_lo)[e]); |
495 | 502 |
(*_excess)[_g.target(e)] += (*_flow)[e]; |
496 | 503 |
(*_excess)[_g.source(e)] -= (*_flow)[e]; |
497 | 504 |
} |
498 | 505 |
|
499 | 506 |
// global relabeling tested, but in general case it provides |
500 | 507 |
// worse performance for random digraphs |
501 | 508 |
_level->initStart(); |
502 | 509 |
for(NodeIt n(_g);n!=INVALID;++n) |
503 | 510 |
_level->initAddItem(n); |
504 | 511 |
_level->initFinish(); |
505 | 512 |
for(NodeIt n(_g);n!=INVALID;++n) |
506 | 513 |
if(_tol.positive((*_excess)[n])) |
507 | 514 |
_level->activate(n); |
508 | 515 |
} |
509 | 516 |
|
510 | 517 |
/// Initializes the internal data structures using a greedy approach. |
511 | 518 |
|
512 | 519 |
/// Initializes the internal data structures using a greedy approach |
513 | 520 |
/// to construct the initial solution. |
514 | 521 |
void greedyInit() |
515 | 522 |
{ |
516 | 523 |
LEMON_DEBUG(checkBoundMaps(), |
517 | 524 |
"Upper bounds must be greater or equal to the lower bounds"); |
518 | 525 |
|
519 | 526 |
createStructures(); |
520 | 527 |
|
521 | 528 |
for(NodeIt n(_g);n!=INVALID;++n) { |
522 | 529 |
(*_excess)[n] = (*_supply)[n]; |
523 | 530 |
} |
524 | 531 |
|
525 | 532 |
for (ArcIt e(_g);e!=INVALID;++e) { |
526 | 533 |
if (!_tol.less(-(*_excess)[_g.target(e)], (*_up)[e])) { |
527 | 534 |
_flow->set(e, (*_up)[e]); |
528 | 535 |
(*_excess)[_g.target(e)] += (*_up)[e]; |
529 | 536 |
(*_excess)[_g.source(e)] -= (*_up)[e]; |
530 | 537 |
} else if (_tol.less(-(*_excess)[_g.target(e)], (*_lo)[e])) { |
531 | 538 |
_flow->set(e, (*_lo)[e]); |
532 | 539 |
(*_excess)[_g.target(e)] += (*_lo)[e]; |
533 | 540 |
(*_excess)[_g.source(e)] -= (*_lo)[e]; |
534 | 541 |
} else { |
535 | 542 |
Value fc = -(*_excess)[_g.target(e)]; |
536 | 543 |
_flow->set(e, fc); |
537 | 544 |
(*_excess)[_g.target(e)] = 0; |
538 | 545 |
(*_excess)[_g.source(e)] -= fc; |
539 | 546 |
} |
540 | 547 |
} |
541 | 548 |
|
542 | 549 |
_level->initStart(); |
543 | 550 |
for(NodeIt n(_g);n!=INVALID;++n) |
544 | 551 |
_level->initAddItem(n); |
545 | 552 |
_level->initFinish(); |
546 | 553 |
for(NodeIt n(_g);n!=INVALID;++n) |
547 | 554 |
if(_tol.positive((*_excess)[n])) |
548 | 555 |
_level->activate(n); |
549 | 556 |
} |
550 | 557 |
|
551 | 558 |
///Executes the algorithm |
552 | 559 |
|
553 | 560 |
///This function executes the algorithm. |
554 | 561 |
/// |
555 | 562 |
///\return \c true if a feasible circulation is found. |
556 | 563 |
/// |
557 | 564 |
///\sa barrier() |
558 | 565 |
///\sa barrierMap() |
559 | 566 |
bool start() |
560 | 567 |
{ |
561 | 568 |
|
562 | 569 |
Node act; |
563 | 570 |
Node bact=INVALID; |
564 | 571 |
Node last_activated=INVALID; |
565 | 572 |
while((act=_level->highestActive())!=INVALID) { |
566 | 573 |
int actlevel=(*_level)[act]; |
567 | 574 |
int mlevel=_node_num; |
568 | 575 |
Value exc=(*_excess)[act]; |
569 | 576 |
|
570 | 577 |
for(OutArcIt e(_g,act);e!=INVALID; ++e) { |
571 | 578 |
Node v = _g.target(e); |
572 | 579 |
Value fc=(*_up)[e]-(*_flow)[e]; |
573 | 580 |
if(!_tol.positive(fc)) continue; |
574 | 581 |
if((*_level)[v]<actlevel) { |
575 | 582 |
if(!_tol.less(fc, exc)) { |
576 | 583 |
_flow->set(e, (*_flow)[e] + exc); |
577 | 584 |
(*_excess)[v] += exc; |
578 | 585 |
if(!_level->active(v) && _tol.positive((*_excess)[v])) |
579 | 586 |
_level->activate(v); |
580 | 587 |
(*_excess)[act] = 0; |
581 | 588 |
_level->deactivate(act); |
582 | 589 |
goto next_l; |
583 | 590 |
} |
584 | 591 |
else { |
585 | 592 |
_flow->set(e, (*_up)[e]); |
586 | 593 |
(*_excess)[v] += fc; |
587 | 594 |
if(!_level->active(v) && _tol.positive((*_excess)[v])) |
588 | 595 |
_level->activate(v); |
589 | 596 |
exc-=fc; |
590 | 597 |
} |
591 | 598 |
} |
592 | 599 |
else if((*_level)[v]<mlevel) mlevel=(*_level)[v]; |
593 | 600 |
} |
594 | 601 |
for(InArcIt e(_g,act);e!=INVALID; ++e) { |
595 | 602 |
Node v = _g.source(e); |
596 | 603 |
Value fc=(*_flow)[e]-(*_lo)[e]; |
597 | 604 |
if(!_tol.positive(fc)) continue; |
598 | 605 |
if((*_level)[v]<actlevel) { |
599 | 606 |
if(!_tol.less(fc, exc)) { |
600 | 607 |
_flow->set(e, (*_flow)[e] - exc); |
601 | 608 |
(*_excess)[v] += exc; |
602 | 609 |
if(!_level->active(v) && _tol.positive((*_excess)[v])) |
603 | 610 |
_level->activate(v); |
604 | 611 |
(*_excess)[act] = 0; |
605 | 612 |
_level->deactivate(act); |
606 | 613 |
goto next_l; |
607 | 614 |
} |
608 | 615 |
else { |
609 | 616 |
_flow->set(e, (*_lo)[e]); |
610 | 617 |
(*_excess)[v] += fc; |
611 | 618 |
if(!_level->active(v) && _tol.positive((*_excess)[v])) |
612 | 619 |
_level->activate(v); |
613 | 620 |
exc-=fc; |
614 | 621 |
} |
615 | 622 |
} |
616 | 623 |
else if((*_level)[v]<mlevel) mlevel=(*_level)[v]; |
617 | 624 |
} |
618 | 625 |
|
619 | 626 |
(*_excess)[act] = exc; |
620 | 627 |
if(!_tol.positive(exc)) _level->deactivate(act); |
621 | 628 |
else if(mlevel==_node_num) { |
622 | 629 |
_level->liftHighestActiveToTop(); |
623 | 630 |
_el = _node_num; |
624 | 631 |
return false; |
625 | 632 |
} |
626 | 633 |
else { |
627 | 634 |
_level->liftHighestActive(mlevel+1); |
628 | 635 |
if(_level->onLevel(actlevel)==0) { |
629 | 636 |
_el = actlevel; |
630 | 637 |
return false; |
631 | 638 |
} |
632 | 639 |
} |
633 | 640 |
next_l: |
634 | 641 |
; |
635 | 642 |
} |
636 | 643 |
return true; |
637 | 644 |
} |
638 | 645 |
|
639 | 646 |
/// Runs the algorithm. |
640 | 647 |
|
641 | 648 |
/// This function runs the algorithm. |
642 | 649 |
/// |
643 | 650 |
/// \return \c true if a feasible circulation is found. |
644 | 651 |
/// |
645 | 652 |
/// \note Apart from the return value, c.run() is just a shortcut of |
646 | 653 |
/// the following code. |
647 | 654 |
/// \code |
648 | 655 |
/// c.greedyInit(); |
649 | 656 |
/// c.start(); |
650 | 657 |
/// \endcode |
651 | 658 |
bool run() { |
652 | 659 |
greedyInit(); |
653 | 660 |
return start(); |
654 | 661 |
} |
655 | 662 |
|
656 | 663 |
/// @} |
657 | 664 |
|
658 | 665 |
/// \name Query Functions |
659 | 666 |
/// The results of the circulation algorithm can be obtained using |
660 | 667 |
/// these functions.\n |
661 | 668 |
/// Either \ref run() or \ref start() should be called before |
662 | 669 |
/// using them. |
663 | 670 |
|
664 | 671 |
///@{ |
665 | 672 |
|
666 | 673 |
/// \brief Returns the flow value on the given arc. |
667 | 674 |
/// |
668 | 675 |
/// Returns the flow value on the given arc. |
669 | 676 |
/// |
670 | 677 |
/// \pre Either \ref run() or \ref init() must be called before |
671 | 678 |
/// using this function. |
672 | 679 |
Value flow(const Arc& arc) const { |
673 | 680 |
return (*_flow)[arc]; |
674 | 681 |
} |
675 | 682 |
|
676 | 683 |
/// \brief Returns a const reference to the flow map. |
677 | 684 |
/// |
678 | 685 |
/// Returns a const reference to the arc map storing the found flow. |
679 | 686 |
/// |
680 | 687 |
/// \pre Either \ref run() or \ref init() must be called before |
681 | 688 |
/// using this function. |
682 | 689 |
const FlowMap& flowMap() const { |
683 | 690 |
return *_flow; |
684 | 691 |
} |
685 | 692 |
|
686 | 693 |
/** |
687 | 694 |
\brief Returns \c true if the given node is in a barrier. |
688 | 695 |
|
689 | 696 |
Barrier is a set \e B of nodes for which |
690 | 697 |
|
691 | 698 |
\f[ \sum_{uv\in A: u\in B} upper(uv) - |
692 | 699 |
\sum_{uv\in A: v\in B} lower(uv) < \sum_{v\in B} sup(v) \f] |
693 | 700 |
|
694 | 701 |
holds. The existence of a set with this property prooves that a |
695 | 702 |
feasible circualtion cannot exist. |
696 | 703 |
|
697 | 704 |
This function returns \c true if the given node is in the found |
698 | 705 |
barrier. If a feasible circulation is found, the function |
699 | 706 |
gives back \c false for every node. |
700 | 707 |
|
701 | 708 |
\pre Either \ref run() or \ref init() must be called before |
702 | 709 |
using this function. |
703 | 710 |
|
704 | 711 |
\sa barrierMap() |
705 | 712 |
\sa checkBarrier() |
706 | 713 |
*/ |
707 | 714 |
bool barrier(const Node& node) const |
708 | 715 |
{ |
709 | 716 |
return (*_level)[node] >= _el; |
710 | 717 |
} |
711 | 718 |
|
712 | 719 |
/// \brief Gives back a barrier. |
713 | 720 |
/// |
714 | 721 |
/// This function sets \c bar to the characteristic vector of the |
715 | 722 |
/// found barrier. \c bar should be a \ref concepts::WriteMap "writable" |
716 | 723 |
/// node map with \c bool (or convertible) value type. |
717 | 724 |
/// |
718 | 725 |
/// If a feasible circulation is found, the function gives back an |
719 | 726 |
/// empty set, so \c bar[v] will be \c false for all nodes \c v. |
720 | 727 |
/// |
721 | 728 |
/// \note This function calls \ref barrier() for each node, |
722 | 729 |
/// so it runs in O(n) time. |
723 | 730 |
/// |
724 | 731 |
/// \pre Either \ref run() or \ref init() must be called before |
725 | 732 |
/// using this function. |
726 | 733 |
/// |
727 | 734 |
/// \sa barrier() |
728 | 735 |
/// \sa checkBarrier() |
729 | 736 |
template<class BarrierMap> |
730 | 737 |
void barrierMap(BarrierMap &bar) const |
731 | 738 |
{ |
732 | 739 |
for(NodeIt n(_g);n!=INVALID;++n) |
733 | 740 |
bar.set(n, (*_level)[n] >= _el); |
734 | 741 |
} |
735 | 742 |
|
736 | 743 |
/// @} |
737 | 744 |
|
738 | 745 |
/// \name Checker Functions |
739 | 746 |
/// The feasibility of the results can be checked using |
740 | 747 |
/// these functions.\n |
741 | 748 |
/// Either \ref run() or \ref start() should be called before |
742 | 749 |
/// using them. |
743 | 750 |
|
744 | 751 |
///@{ |
745 | 752 |
|
746 | 753 |
///Check if the found flow is a feasible circulation |
747 | 754 |
|
748 | 755 |
///Check if the found flow is a feasible circulation, |
749 | 756 |
/// |
750 | 757 |
bool checkFlow() const { |
751 | 758 |
for(ArcIt e(_g);e!=INVALID;++e) |
752 | 759 |
if((*_flow)[e]<(*_lo)[e]||(*_flow)[e]>(*_up)[e]) return false; |
753 | 760 |
for(NodeIt n(_g);n!=INVALID;++n) |
754 | 761 |
{ |
755 | 762 |
Value dif=-(*_supply)[n]; |
756 | 763 |
for(InArcIt e(_g,n);e!=INVALID;++e) dif-=(*_flow)[e]; |
757 | 764 |
for(OutArcIt e(_g,n);e!=INVALID;++e) dif+=(*_flow)[e]; |
758 | 765 |
if(_tol.negative(dif)) return false; |
759 | 766 |
} |
760 | 767 |
return true; |
761 | 768 |
} |
762 | 769 |
|
763 | 770 |
///Check whether or not the last execution provides a barrier |
764 | 771 |
|
765 | 772 |
///Check whether or not the last execution provides a barrier. |
766 | 773 |
///\sa barrier() |
767 | 774 |
///\sa barrierMap() |
768 | 775 |
bool checkBarrier() const |
769 | 776 |
{ |
770 | 777 |
Value delta=0; |
771 | 778 |
Value inf_cap = std::numeric_limits<Value>::has_infinity ? |
772 | 779 |
std::numeric_limits<Value>::infinity() : |
773 | 780 |
std::numeric_limits<Value>::max(); |
774 | 781 |
for(NodeIt n(_g);n!=INVALID;++n) |
775 | 782 |
if(barrier(n)) |
776 | 783 |
delta-=(*_supply)[n]; |
777 | 784 |
for(ArcIt e(_g);e!=INVALID;++e) |
778 | 785 |
{ |
779 | 786 |
Node s=_g.source(e); |
780 | 787 |
Node t=_g.target(e); |
781 | 788 |
if(barrier(s)&&!barrier(t)) { |
782 | 789 |
if (_tol.less(inf_cap - (*_up)[e], delta)) return false; |
783 | 790 |
delta+=(*_up)[e]; |
784 | 791 |
} |
785 | 792 |
else if(barrier(t)&&!barrier(s)) delta-=(*_lo)[e]; |
786 | 793 |
} |
787 | 794 |
return _tol.negative(delta); |
788 | 795 |
} |
789 | 796 |
|
790 | 797 |
/// @} |
791 | 798 |
|
792 | 799 |
}; |
793 | 800 |
|
794 | 801 |
} |
795 | 802 |
|
796 | 803 |
#endif |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_CONCEPTS_MAPS_H |
20 | 20 |
#define LEMON_CONCEPTS_MAPS_H |
21 | 21 |
|
22 | 22 |
#include <lemon/core.h> |
23 | 23 |
#include <lemon/concept_check.h> |
24 | 24 |
|
25 | 25 |
///\ingroup map_concepts |
26 | 26 |
///\file |
27 | 27 |
///\brief The concept of maps. |
28 | 28 |
|
29 | 29 |
namespace lemon { |
30 | 30 |
|
31 | 31 |
namespace concepts { |
32 | 32 |
|
33 | 33 |
/// \addtogroup map_concepts |
34 | 34 |
/// @{ |
35 | 35 |
|
36 | 36 |
/// Readable map concept |
37 | 37 |
|
38 | 38 |
/// Readable map concept. |
39 | 39 |
/// |
40 | 40 |
template<typename K, typename T> |
41 | 41 |
class ReadMap |
42 | 42 |
{ |
43 | 43 |
public: |
44 | 44 |
/// The key type of the map. |
45 | 45 |
typedef K Key; |
46 | 46 |
/// \brief The value type of the map. |
47 | 47 |
/// (The type of objects associated with the keys). |
48 | 48 |
typedef T Value; |
49 | 49 |
|
50 | 50 |
/// Returns the value associated with the given key. |
51 | 51 |
Value operator[](const Key &) const { |
52 | 52 |
return *static_cast<Value *>(0); |
53 | 53 |
} |
54 | 54 |
|
55 | 55 |
template<typename _ReadMap> |
56 | 56 |
struct Constraints { |
57 | 57 |
void constraints() { |
58 | 58 |
Value val = m[key]; |
59 | 59 |
val = m[key]; |
60 | 60 |
typename _ReadMap::Value own_val = m[own_key]; |
61 | 61 |
own_val = m[own_key]; |
62 | 62 |
|
63 | 63 |
ignore_unused_variable_warning(key); |
64 | 64 |
ignore_unused_variable_warning(val); |
65 | 65 |
ignore_unused_variable_warning(own_key); |
66 | 66 |
ignore_unused_variable_warning(own_val); |
67 | 67 |
} |
68 | 68 |
const Key& key; |
69 | 69 |
const typename _ReadMap::Key& own_key; |
70 | 70 |
const _ReadMap& m; |
71 | 71 |
}; |
72 | 72 |
|
73 | 73 |
}; |
74 | 74 |
|
75 | 75 |
|
76 | 76 |
/// Writable map concept |
77 | 77 |
|
78 | 78 |
/// Writable map concept. |
79 | 79 |
/// |
80 | 80 |
template<typename K, typename T> |
81 | 81 |
class WriteMap |
82 | 82 |
{ |
83 | 83 |
public: |
84 | 84 |
/// The key type of the map. |
85 | 85 |
typedef K Key; |
86 | 86 |
/// \brief The value type of the map. |
87 | 87 |
/// (The type of objects associated with the keys). |
88 | 88 |
typedef T Value; |
89 | 89 |
|
90 | 90 |
/// Sets the value associated with the given key. |
91 | 91 |
void set(const Key &, const Value &) {} |
92 | 92 |
|
93 | 93 |
/// Default constructor. |
94 | 94 |
WriteMap() {} |
95 | 95 |
|
96 | 96 |
template <typename _WriteMap> |
97 | 97 |
struct Constraints { |
98 | 98 |
void constraints() { |
99 | 99 |
m.set(key, val); |
100 | 100 |
m.set(own_key, own_val); |
101 | 101 |
|
102 | 102 |
ignore_unused_variable_warning(key); |
103 | 103 |
ignore_unused_variable_warning(val); |
104 | 104 |
ignore_unused_variable_warning(own_key); |
105 | 105 |
ignore_unused_variable_warning(own_val); |
106 | 106 |
} |
107 | 107 |
const Key& key; |
108 | 108 |
const Value& val; |
109 | 109 |
const typename _WriteMap::Key& own_key; |
110 | 110 |
const typename _WriteMap::Value& own_val; |
111 | 111 |
_WriteMap& m; |
112 | 112 |
}; |
113 | 113 |
}; |
114 | 114 |
|
115 | 115 |
/// Read/writable map concept |
116 | 116 |
|
117 | 117 |
/// Read/writable map concept. |
118 | 118 |
/// |
119 | 119 |
template<typename K, typename T> |
120 | 120 |
class ReadWriteMap : public ReadMap<K,T>, |
121 | 121 |
public WriteMap<K,T> |
122 | 122 |
{ |
123 | 123 |
public: |
124 | 124 |
/// The key type of the map. |
125 | 125 |
typedef K Key; |
126 | 126 |
/// \brief The value type of the map. |
127 | 127 |
/// (The type of objects associated with the keys). |
128 | 128 |
typedef T Value; |
129 | 129 |
|
130 | 130 |
/// Returns the value associated with the given key. |
131 | 131 |
Value operator[](const Key &) const { |
132 | 132 |
return *static_cast<Value *>(0); |
133 | 133 |
} |
134 | 134 |
|
135 | 135 |
/// Sets the value associated with the given key. |
136 | 136 |
void set(const Key &, const Value &) {} |
137 | 137 |
|
138 | 138 |
template<typename _ReadWriteMap> |
139 | 139 |
struct Constraints { |
140 | 140 |
void constraints() { |
141 | 141 |
checkConcept<ReadMap<K, T>, _ReadWriteMap >(); |
142 | 142 |
checkConcept<WriteMap<K, T>, _ReadWriteMap >(); |
143 | 143 |
} |
144 | 144 |
}; |
145 | 145 |
}; |
146 | 146 |
|
147 | 147 |
|
148 | 148 |
/// Dereferable map concept |
149 | 149 |
|
150 | 150 |
/// Dereferable map concept. |
151 | 151 |
/// |
152 | 152 |
template<typename K, typename T, typename R, typename CR> |
153 | 153 |
class ReferenceMap : public ReadWriteMap<K,T> |
154 | 154 |
{ |
155 | 155 |
public: |
156 | 156 |
/// Tag for reference maps. |
157 | 157 |
typedef True ReferenceMapTag; |
158 | 158 |
/// The key type of the map. |
159 | 159 |
typedef K Key; |
160 | 160 |
/// \brief The value type of the map. |
161 | 161 |
/// (The type of objects associated with the keys). |
162 | 162 |
typedef T Value; |
163 | 163 |
/// The reference type of the map. |
164 | 164 |
typedef R Reference; |
165 | 165 |
/// The const reference type of the map. |
166 | 166 |
typedef CR ConstReference; |
167 | 167 |
|
168 | 168 |
public: |
169 | 169 |
|
170 | 170 |
/// Returns a reference to the value associated with the given key. |
171 | 171 |
Reference operator[](const Key &) { |
172 | 172 |
return *static_cast<Value *>(0); |
173 | 173 |
} |
174 | 174 |
|
175 | 175 |
/// Returns a const reference to the value associated with the given key. |
176 | 176 |
ConstReference operator[](const Key &) const { |
177 | 177 |
return *static_cast<Value *>(0); |
178 | 178 |
} |
179 | 179 |
|
180 | 180 |
/// Sets the value associated with the given key. |
181 | 181 |
void set(const Key &k,const Value &t) { operator[](k)=t; } |
182 | 182 |
|
183 | 183 |
template<typename _ReferenceMap> |
184 | 184 |
struct Constraints { |
185 |
|
|
185 |
typename enable_if<typename _ReferenceMap::ReferenceMapTag, void>::type |
|
186 |
constraints() { |
|
186 | 187 |
checkConcept<ReadWriteMap<K, T>, _ReferenceMap >(); |
187 | 188 |
ref = m[key]; |
188 | 189 |
m[key] = val; |
189 | 190 |
m[key] = ref; |
190 | 191 |
m[key] = cref; |
191 | 192 |
own_ref = m[own_key]; |
192 | 193 |
m[own_key] = own_val; |
193 | 194 |
m[own_key] = own_ref; |
194 | 195 |
m[own_key] = own_cref; |
195 | 196 |
m[key] = m[own_key]; |
196 | 197 |
m[own_key] = m[key]; |
197 | 198 |
} |
198 | 199 |
const Key& key; |
199 | 200 |
Value& val; |
200 | 201 |
Reference ref; |
201 | 202 |
ConstReference cref; |
202 | 203 |
const typename _ReferenceMap::Key& own_key; |
203 | 204 |
typename _ReferenceMap::Value& own_val; |
204 | 205 |
typename _ReferenceMap::Reference own_ref; |
205 | 206 |
typename _ReferenceMap::ConstReference own_cref; |
206 | 207 |
_ReferenceMap& m; |
207 | 208 |
}; |
208 | 209 |
}; |
209 | 210 |
|
210 | 211 |
// @} |
211 | 212 |
|
212 | 213 |
} //namespace concepts |
213 | 214 |
|
214 | 215 |
} //namespace lemon |
215 | 216 |
|
216 | 217 |
#endif |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_DFS_H |
20 | 20 |
#define LEMON_DFS_H |
21 | 21 |
|
22 | 22 |
///\ingroup search |
23 | 23 |
///\file |
24 | 24 |
///\brief DFS algorithm. |
25 | 25 |
|
26 | 26 |
#include <lemon/list_graph.h> |
27 | 27 |
#include <lemon/bits/path_dump.h> |
28 | 28 |
#include <lemon/core.h> |
29 | 29 |
#include <lemon/error.h> |
30 | 30 |
#include <lemon/maps.h> |
31 | 31 |
#include <lemon/path.h> |
32 | 32 |
|
33 | 33 |
namespace lemon { |
34 | 34 |
|
35 | 35 |
///Default traits class of Dfs class. |
36 | 36 |
|
37 | 37 |
///Default traits class of Dfs class. |
38 | 38 |
///\tparam GR Digraph type. |
39 | 39 |
template<class GR> |
40 | 40 |
struct DfsDefaultTraits |
41 | 41 |
{ |
42 | 42 |
///The type of the digraph the algorithm runs on. |
43 | 43 |
typedef GR Digraph; |
44 | 44 |
|
45 | 45 |
///\brief The type of the map that stores the predecessor |
46 | 46 |
///arcs of the %DFS paths. |
47 | 47 |
/// |
48 | 48 |
///The type of the map that stores the predecessor |
49 | 49 |
///arcs of the %DFS paths. |
50 |
///It must |
|
50 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
51 | 51 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
52 | 52 |
///Instantiates a \c PredMap. |
53 | 53 |
|
54 | 54 |
///This function instantiates a \ref PredMap. |
55 | 55 |
///\param g is the digraph, to which we would like to define the |
56 | 56 |
///\ref PredMap. |
57 | 57 |
static PredMap *createPredMap(const Digraph &g) |
58 | 58 |
{ |
59 | 59 |
return new PredMap(g); |
60 | 60 |
} |
61 | 61 |
|
62 | 62 |
///The type of the map that indicates which nodes are processed. |
63 | 63 |
|
64 | 64 |
///The type of the map that indicates which nodes are processed. |
65 |
///It must |
|
65 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
66 |
///By default it is a NullMap. |
|
66 | 67 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
67 | 68 |
///Instantiates a \c ProcessedMap. |
68 | 69 |
|
69 | 70 |
///This function instantiates a \ref ProcessedMap. |
70 | 71 |
///\param g is the digraph, to which |
71 | 72 |
///we would like to define the \ref ProcessedMap. |
72 | 73 |
#ifdef DOXYGEN |
73 | 74 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
74 | 75 |
#else |
75 | 76 |
static ProcessedMap *createProcessedMap(const Digraph &) |
76 | 77 |
#endif |
77 | 78 |
{ |
78 | 79 |
return new ProcessedMap(); |
79 | 80 |
} |
80 | 81 |
|
81 | 82 |
///The type of the map that indicates which nodes are reached. |
82 | 83 |
|
83 | 84 |
///The type of the map that indicates which nodes are reached. |
84 |
///It must |
|
85 |
///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
85 | 86 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
86 | 87 |
///Instantiates a \c ReachedMap. |
87 | 88 |
|
88 | 89 |
///This function instantiates a \ref ReachedMap. |
89 | 90 |
///\param g is the digraph, to which |
90 | 91 |
///we would like to define the \ref ReachedMap. |
91 | 92 |
static ReachedMap *createReachedMap(const Digraph &g) |
92 | 93 |
{ |
93 | 94 |
return new ReachedMap(g); |
94 | 95 |
} |
95 | 96 |
|
96 | 97 |
///The type of the map that stores the distances of the nodes. |
97 | 98 |
|
98 | 99 |
///The type of the map that stores the distances of the nodes. |
99 |
///It must |
|
100 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
100 | 101 |
typedef typename Digraph::template NodeMap<int> DistMap; |
101 | 102 |
///Instantiates a \c DistMap. |
102 | 103 |
|
103 | 104 |
///This function instantiates a \ref DistMap. |
104 | 105 |
///\param g is the digraph, to which we would like to define the |
105 | 106 |
///\ref DistMap. |
106 | 107 |
static DistMap *createDistMap(const Digraph &g) |
107 | 108 |
{ |
108 | 109 |
return new DistMap(g); |
109 | 110 |
} |
110 | 111 |
}; |
111 | 112 |
|
112 | 113 |
///%DFS algorithm class. |
113 | 114 |
|
114 | 115 |
///\ingroup search |
115 | 116 |
///This class provides an efficient implementation of the %DFS algorithm. |
116 | 117 |
/// |
117 | 118 |
///There is also a \ref dfs() "function-type interface" for the DFS |
118 | 119 |
///algorithm, which is convenient in the simplier cases and it can be |
119 | 120 |
///used easier. |
120 | 121 |
/// |
121 | 122 |
///\tparam GR The type of the digraph the algorithm runs on. |
122 | 123 |
///The default type is \ref ListDigraph. |
123 | 124 |
#ifdef DOXYGEN |
124 | 125 |
template <typename GR, |
125 | 126 |
typename TR> |
126 | 127 |
#else |
127 | 128 |
template <typename GR=ListDigraph, |
128 | 129 |
typename TR=DfsDefaultTraits<GR> > |
129 | 130 |
#endif |
130 | 131 |
class Dfs { |
131 | 132 |
public: |
132 | 133 |
|
133 | 134 |
///The type of the digraph the algorithm runs on. |
134 | 135 |
typedef typename TR::Digraph Digraph; |
135 | 136 |
|
136 | 137 |
///\brief The type of the map that stores the predecessor arcs of the |
137 | 138 |
///DFS paths. |
138 | 139 |
typedef typename TR::PredMap PredMap; |
139 | 140 |
///The type of the map that stores the distances of the nodes. |
140 | 141 |
typedef typename TR::DistMap DistMap; |
141 | 142 |
///The type of the map that indicates which nodes are reached. |
142 | 143 |
typedef typename TR::ReachedMap ReachedMap; |
143 | 144 |
///The type of the map that indicates which nodes are processed. |
144 | 145 |
typedef typename TR::ProcessedMap ProcessedMap; |
145 | 146 |
///The type of the paths. |
146 | 147 |
typedef PredMapPath<Digraph, PredMap> Path; |
147 | 148 |
|
148 | 149 |
///The \ref DfsDefaultTraits "traits class" of the algorithm. |
149 | 150 |
typedef TR Traits; |
150 | 151 |
|
151 | 152 |
private: |
152 | 153 |
|
153 | 154 |
typedef typename Digraph::Node Node; |
154 | 155 |
typedef typename Digraph::NodeIt NodeIt; |
155 | 156 |
typedef typename Digraph::Arc Arc; |
156 | 157 |
typedef typename Digraph::OutArcIt OutArcIt; |
157 | 158 |
|
158 | 159 |
//Pointer to the underlying digraph. |
159 | 160 |
const Digraph *G; |
160 | 161 |
//Pointer to the map of predecessor arcs. |
161 | 162 |
PredMap *_pred; |
162 | 163 |
//Indicates if _pred is locally allocated (true) or not. |
163 | 164 |
bool local_pred; |
164 | 165 |
//Pointer to the map of distances. |
165 | 166 |
DistMap *_dist; |
166 | 167 |
//Indicates if _dist is locally allocated (true) or not. |
167 | 168 |
bool local_dist; |
168 | 169 |
//Pointer to the map of reached status of the nodes. |
169 | 170 |
ReachedMap *_reached; |
170 | 171 |
//Indicates if _reached is locally allocated (true) or not. |
171 | 172 |
bool local_reached; |
172 | 173 |
//Pointer to the map of processed status of the nodes. |
173 | 174 |
ProcessedMap *_processed; |
174 | 175 |
//Indicates if _processed is locally allocated (true) or not. |
175 | 176 |
bool local_processed; |
176 | 177 |
|
177 | 178 |
std::vector<typename Digraph::OutArcIt> _stack; |
178 | 179 |
int _stack_head; |
179 | 180 |
|
180 | 181 |
//Creates the maps if necessary. |
181 | 182 |
void create_maps() |
182 | 183 |
{ |
183 | 184 |
if(!_pred) { |
184 | 185 |
local_pred = true; |
185 | 186 |
_pred = Traits::createPredMap(*G); |
186 | 187 |
} |
187 | 188 |
if(!_dist) { |
188 | 189 |
local_dist = true; |
189 | 190 |
_dist = Traits::createDistMap(*G); |
190 | 191 |
} |
191 | 192 |
if(!_reached) { |
192 | 193 |
local_reached = true; |
193 | 194 |
_reached = Traits::createReachedMap(*G); |
194 | 195 |
} |
195 | 196 |
if(!_processed) { |
196 | 197 |
local_processed = true; |
197 | 198 |
_processed = Traits::createProcessedMap(*G); |
198 | 199 |
} |
199 | 200 |
} |
200 | 201 |
|
201 | 202 |
protected: |
202 | 203 |
|
203 | 204 |
Dfs() {} |
204 | 205 |
|
205 | 206 |
public: |
206 | 207 |
|
207 | 208 |
typedef Dfs Create; |
208 | 209 |
|
209 | 210 |
///\name Named Template Parameters |
210 | 211 |
|
211 | 212 |
///@{ |
212 | 213 |
|
213 | 214 |
template <class T> |
214 | 215 |
struct SetPredMapTraits : public Traits { |
215 | 216 |
typedef T PredMap; |
216 | 217 |
static PredMap *createPredMap(const Digraph &) |
217 | 218 |
{ |
218 | 219 |
LEMON_ASSERT(false, "PredMap is not initialized"); |
219 | 220 |
return 0; // ignore warnings |
220 | 221 |
} |
221 | 222 |
}; |
222 | 223 |
///\brief \ref named-templ-param "Named parameter" for setting |
223 | 224 |
///\c PredMap type. |
224 | 225 |
/// |
225 | 226 |
///\ref named-templ-param "Named parameter" for setting |
226 | 227 |
///\c PredMap type. |
227 |
///It must |
|
228 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
228 | 229 |
template <class T> |
229 | 230 |
struct SetPredMap : public Dfs<Digraph, SetPredMapTraits<T> > { |
230 | 231 |
typedef Dfs<Digraph, SetPredMapTraits<T> > Create; |
231 | 232 |
}; |
232 | 233 |
|
233 | 234 |
template <class T> |
234 | 235 |
struct SetDistMapTraits : public Traits { |
235 | 236 |
typedef T DistMap; |
236 | 237 |
static DistMap *createDistMap(const Digraph &) |
237 | 238 |
{ |
238 | 239 |
LEMON_ASSERT(false, "DistMap is not initialized"); |
239 | 240 |
return 0; // ignore warnings |
240 | 241 |
} |
241 | 242 |
}; |
242 | 243 |
///\brief \ref named-templ-param "Named parameter" for setting |
243 | 244 |
///\c DistMap type. |
244 | 245 |
/// |
245 | 246 |
///\ref named-templ-param "Named parameter" for setting |
246 | 247 |
///\c DistMap type. |
247 |
///It must |
|
248 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
248 | 249 |
template <class T> |
249 | 250 |
struct SetDistMap : public Dfs< Digraph, SetDistMapTraits<T> > { |
250 | 251 |
typedef Dfs<Digraph, SetDistMapTraits<T> > Create; |
251 | 252 |
}; |
252 | 253 |
|
253 | 254 |
template <class T> |
254 | 255 |
struct SetReachedMapTraits : public Traits { |
255 | 256 |
typedef T ReachedMap; |
256 | 257 |
static ReachedMap *createReachedMap(const Digraph &) |
257 | 258 |
{ |
258 | 259 |
LEMON_ASSERT(false, "ReachedMap is not initialized"); |
259 | 260 |
return 0; // ignore warnings |
260 | 261 |
} |
261 | 262 |
}; |
262 | 263 |
///\brief \ref named-templ-param "Named parameter" for setting |
263 | 264 |
///\c ReachedMap type. |
264 | 265 |
/// |
265 | 266 |
///\ref named-templ-param "Named parameter" for setting |
266 | 267 |
///\c ReachedMap type. |
267 |
///It must |
|
268 |
///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
268 | 269 |
template <class T> |
269 | 270 |
struct SetReachedMap : public Dfs< Digraph, SetReachedMapTraits<T> > { |
270 | 271 |
typedef Dfs< Digraph, SetReachedMapTraits<T> > Create; |
271 | 272 |
}; |
272 | 273 |
|
273 | 274 |
template <class T> |
274 | 275 |
struct SetProcessedMapTraits : public Traits { |
275 | 276 |
typedef T ProcessedMap; |
276 | 277 |
static ProcessedMap *createProcessedMap(const Digraph &) |
277 | 278 |
{ |
278 | 279 |
LEMON_ASSERT(false, "ProcessedMap is not initialized"); |
279 | 280 |
return 0; // ignore warnings |
280 | 281 |
} |
281 | 282 |
}; |
282 | 283 |
///\brief \ref named-templ-param "Named parameter" for setting |
283 | 284 |
///\c ProcessedMap type. |
284 | 285 |
/// |
285 | 286 |
///\ref named-templ-param "Named parameter" for setting |
286 | 287 |
///\c ProcessedMap type. |
287 |
///It must |
|
288 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
288 | 289 |
template <class T> |
289 | 290 |
struct SetProcessedMap : public Dfs< Digraph, SetProcessedMapTraits<T> > { |
290 | 291 |
typedef Dfs< Digraph, SetProcessedMapTraits<T> > Create; |
291 | 292 |
}; |
292 | 293 |
|
293 | 294 |
struct SetStandardProcessedMapTraits : public Traits { |
294 | 295 |
typedef typename Digraph::template NodeMap<bool> ProcessedMap; |
295 | 296 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
296 | 297 |
{ |
297 | 298 |
return new ProcessedMap(g); |
298 | 299 |
} |
299 | 300 |
}; |
300 | 301 |
///\brief \ref named-templ-param "Named parameter" for setting |
301 | 302 |
///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
302 | 303 |
/// |
303 | 304 |
///\ref named-templ-param "Named parameter" for setting |
304 | 305 |
///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
305 | 306 |
///If you don't set it explicitly, it will be automatically allocated. |
306 | 307 |
struct SetStandardProcessedMap : |
307 | 308 |
public Dfs< Digraph, SetStandardProcessedMapTraits > { |
308 | 309 |
typedef Dfs< Digraph, SetStandardProcessedMapTraits > Create; |
309 | 310 |
}; |
310 | 311 |
|
311 | 312 |
///@} |
312 | 313 |
|
313 | 314 |
public: |
314 | 315 |
|
315 | 316 |
///Constructor. |
316 | 317 |
|
317 | 318 |
///Constructor. |
318 | 319 |
///\param g The digraph the algorithm runs on. |
319 | 320 |
Dfs(const Digraph &g) : |
320 | 321 |
G(&g), |
321 | 322 |
_pred(NULL), local_pred(false), |
322 | 323 |
_dist(NULL), local_dist(false), |
323 | 324 |
_reached(NULL), local_reached(false), |
324 | 325 |
_processed(NULL), local_processed(false) |
325 | 326 |
{ } |
326 | 327 |
|
327 | 328 |
///Destructor. |
328 | 329 |
~Dfs() |
329 | 330 |
{ |
330 | 331 |
if(local_pred) delete _pred; |
331 | 332 |
if(local_dist) delete _dist; |
332 | 333 |
if(local_reached) delete _reached; |
333 | 334 |
if(local_processed) delete _processed; |
334 | 335 |
} |
335 | 336 |
|
336 | 337 |
///Sets the map that stores the predecessor arcs. |
337 | 338 |
|
338 | 339 |
///Sets the map that stores the predecessor arcs. |
339 | 340 |
///If you don't use this function before calling \ref run(Node) "run()" |
340 | 341 |
///or \ref init(), an instance will be allocated automatically. |
341 | 342 |
///The destructor deallocates this automatically allocated map, |
342 | 343 |
///of course. |
343 | 344 |
///\return <tt> (*this) </tt> |
344 | 345 |
Dfs &predMap(PredMap &m) |
345 | 346 |
{ |
346 | 347 |
if(local_pred) { |
347 | 348 |
delete _pred; |
348 | 349 |
local_pred=false; |
349 | 350 |
} |
350 | 351 |
_pred = &m; |
351 | 352 |
return *this; |
352 | 353 |
} |
353 | 354 |
|
354 | 355 |
///Sets the map that indicates which nodes are reached. |
355 | 356 |
|
356 | 357 |
///Sets the map that indicates which nodes are reached. |
357 | 358 |
///If you don't use this function before calling \ref run(Node) "run()" |
358 | 359 |
///or \ref init(), an instance will be allocated automatically. |
359 | 360 |
///The destructor deallocates this automatically allocated map, |
360 | 361 |
///of course. |
361 | 362 |
///\return <tt> (*this) </tt> |
362 | 363 |
Dfs &reachedMap(ReachedMap &m) |
363 | 364 |
{ |
364 | 365 |
if(local_reached) { |
365 | 366 |
delete _reached; |
366 | 367 |
local_reached=false; |
367 | 368 |
} |
368 | 369 |
_reached = &m; |
369 | 370 |
return *this; |
370 | 371 |
} |
371 | 372 |
|
372 | 373 |
///Sets the map that indicates which nodes are processed. |
373 | 374 |
|
374 | 375 |
///Sets the map that indicates which nodes are processed. |
375 | 376 |
///If you don't use this function before calling \ref run(Node) "run()" |
376 | 377 |
///or \ref init(), an instance will be allocated automatically. |
377 | 378 |
///The destructor deallocates this automatically allocated map, |
378 | 379 |
///of course. |
379 | 380 |
///\return <tt> (*this) </tt> |
380 | 381 |
Dfs &processedMap(ProcessedMap &m) |
381 | 382 |
{ |
382 | 383 |
if(local_processed) { |
383 | 384 |
delete _processed; |
384 | 385 |
local_processed=false; |
385 | 386 |
} |
386 | 387 |
_processed = &m; |
387 | 388 |
return *this; |
388 | 389 |
} |
389 | 390 |
|
390 | 391 |
///Sets the map that stores the distances of the nodes. |
391 | 392 |
|
392 | 393 |
///Sets the map that stores the distances of the nodes calculated by |
393 | 394 |
///the algorithm. |
394 | 395 |
///If you don't use this function before calling \ref run(Node) "run()" |
395 | 396 |
///or \ref init(), an instance will be allocated automatically. |
396 | 397 |
///The destructor deallocates this automatically allocated map, |
397 | 398 |
///of course. |
398 | 399 |
///\return <tt> (*this) </tt> |
399 | 400 |
Dfs &distMap(DistMap &m) |
400 | 401 |
{ |
401 | 402 |
if(local_dist) { |
402 | 403 |
delete _dist; |
403 | 404 |
local_dist=false; |
404 | 405 |
} |
405 | 406 |
_dist = &m; |
406 | 407 |
return *this; |
407 | 408 |
} |
408 | 409 |
|
409 | 410 |
public: |
410 | 411 |
|
411 | 412 |
///\name Execution Control |
412 | 413 |
///The simplest way to execute the DFS algorithm is to use one of the |
413 | 414 |
///member functions called \ref run(Node) "run()".\n |
414 |
///If you need more control on the execution, first you have to call |
|
415 |
///\ref init(), then you can add a source node with \ref addSource() |
|
415 |
///If you need better control on the execution, you have to call |
|
416 |
///\ref init() first, then you can add a source node with \ref addSource() |
|
416 | 417 |
///and perform the actual computation with \ref start(). |
417 | 418 |
///This procedure can be repeated if there are nodes that have not |
418 | 419 |
///been reached. |
419 | 420 |
|
420 | 421 |
///@{ |
421 | 422 |
|
422 | 423 |
///\brief Initializes the internal data structures. |
423 | 424 |
/// |
424 | 425 |
///Initializes the internal data structures. |
425 | 426 |
void init() |
426 | 427 |
{ |
427 | 428 |
create_maps(); |
428 | 429 |
_stack.resize(countNodes(*G)); |
429 | 430 |
_stack_head=-1; |
430 | 431 |
for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
431 | 432 |
_pred->set(u,INVALID); |
432 | 433 |
_reached->set(u,false); |
433 | 434 |
_processed->set(u,false); |
434 | 435 |
} |
435 | 436 |
} |
436 | 437 |
|
437 | 438 |
///Adds a new source node. |
438 | 439 |
|
439 | 440 |
///Adds a new source node to the set of nodes to be processed. |
440 | 441 |
/// |
441 | 442 |
///\pre The stack must be empty. Otherwise the algorithm gives |
442 | 443 |
///wrong results. (One of the outgoing arcs of all the source nodes |
443 | 444 |
///except for the last one will not be visited and distances will |
444 | 445 |
///also be wrong.) |
445 | 446 |
void addSource(Node s) |
446 | 447 |
{ |
447 | 448 |
LEMON_DEBUG(emptyQueue(), "The stack is not empty."); |
448 | 449 |
if(!(*_reached)[s]) |
449 | 450 |
{ |
450 | 451 |
_reached->set(s,true); |
451 | 452 |
_pred->set(s,INVALID); |
452 | 453 |
OutArcIt e(*G,s); |
453 | 454 |
if(e!=INVALID) { |
454 | 455 |
_stack[++_stack_head]=e; |
455 | 456 |
_dist->set(s,_stack_head); |
456 | 457 |
} |
457 | 458 |
else { |
458 | 459 |
_processed->set(s,true); |
459 | 460 |
_dist->set(s,0); |
460 | 461 |
} |
461 | 462 |
} |
462 | 463 |
} |
463 | 464 |
|
464 | 465 |
///Processes the next arc. |
465 | 466 |
|
466 | 467 |
///Processes the next arc. |
467 | 468 |
/// |
468 | 469 |
///\return The processed arc. |
469 | 470 |
/// |
470 | 471 |
///\pre The stack must not be empty. |
471 | 472 |
Arc processNextArc() |
472 | 473 |
{ |
473 | 474 |
Node m; |
474 | 475 |
Arc e=_stack[_stack_head]; |
475 | 476 |
if(!(*_reached)[m=G->target(e)]) { |
476 | 477 |
_pred->set(m,e); |
477 | 478 |
_reached->set(m,true); |
478 | 479 |
++_stack_head; |
479 | 480 |
_stack[_stack_head] = OutArcIt(*G, m); |
480 | 481 |
_dist->set(m,_stack_head); |
481 | 482 |
} |
482 | 483 |
else { |
483 | 484 |
m=G->source(e); |
484 | 485 |
++_stack[_stack_head]; |
485 | 486 |
} |
486 | 487 |
while(_stack_head>=0 && _stack[_stack_head]==INVALID) { |
487 | 488 |
_processed->set(m,true); |
488 | 489 |
--_stack_head; |
489 | 490 |
if(_stack_head>=0) { |
490 | 491 |
m=G->source(_stack[_stack_head]); |
491 | 492 |
++_stack[_stack_head]; |
492 | 493 |
} |
493 | 494 |
} |
494 | 495 |
return e; |
495 | 496 |
} |
496 | 497 |
|
497 | 498 |
///Next arc to be processed. |
498 | 499 |
|
499 | 500 |
///Next arc to be processed. |
500 | 501 |
/// |
501 | 502 |
///\return The next arc to be processed or \c INVALID if the stack |
502 | 503 |
///is empty. |
503 | 504 |
OutArcIt nextArc() const |
504 | 505 |
{ |
505 | 506 |
return _stack_head>=0?_stack[_stack_head]:INVALID; |
506 | 507 |
} |
507 | 508 |
|
508 | 509 |
///Returns \c false if there are nodes to be processed. |
509 | 510 |
|
510 | 511 |
///Returns \c false if there are nodes to be processed |
511 | 512 |
///in the queue (stack). |
512 | 513 |
bool emptyQueue() const { return _stack_head<0; } |
513 | 514 |
|
514 | 515 |
///Returns the number of the nodes to be processed. |
515 | 516 |
|
516 | 517 |
///Returns the number of the nodes to be processed |
517 | 518 |
///in the queue (stack). |
518 | 519 |
int queueSize() const { return _stack_head+1; } |
519 | 520 |
|
520 | 521 |
///Executes the algorithm. |
521 | 522 |
|
522 | 523 |
///Executes the algorithm. |
523 | 524 |
/// |
524 | 525 |
///This method runs the %DFS algorithm from the root node |
525 | 526 |
///in order to compute the DFS path to each node. |
526 | 527 |
/// |
527 | 528 |
/// The algorithm computes |
528 | 529 |
///- the %DFS tree, |
529 | 530 |
///- the distance of each node from the root in the %DFS tree. |
530 | 531 |
/// |
531 | 532 |
///\pre init() must be called and a root node should be |
532 | 533 |
///added with addSource() before using this function. |
533 | 534 |
/// |
534 | 535 |
///\note <tt>d.start()</tt> is just a shortcut of the following code. |
535 | 536 |
///\code |
536 | 537 |
/// while ( !d.emptyQueue() ) { |
537 | 538 |
/// d.processNextArc(); |
538 | 539 |
/// } |
539 | 540 |
///\endcode |
540 | 541 |
void start() |
541 | 542 |
{ |
542 | 543 |
while ( !emptyQueue() ) processNextArc(); |
543 | 544 |
} |
544 | 545 |
|
545 | 546 |
///Executes the algorithm until the given target node is reached. |
546 | 547 |
|
547 | 548 |
///Executes the algorithm until the given target node is reached. |
548 | 549 |
/// |
549 | 550 |
///This method runs the %DFS algorithm from the root node |
550 | 551 |
///in order to compute the DFS path to \c t. |
551 | 552 |
/// |
552 | 553 |
///The algorithm computes |
553 | 554 |
///- the %DFS path to \c t, |
554 | 555 |
///- the distance of \c t from the root in the %DFS tree. |
555 | 556 |
/// |
556 | 557 |
///\pre init() must be called and a root node should be |
557 | 558 |
///added with addSource() before using this function. |
558 | 559 |
void start(Node t) |
559 | 560 |
{ |
560 | 561 |
while ( !emptyQueue() && G->target(_stack[_stack_head])!=t ) |
561 | 562 |
processNextArc(); |
562 | 563 |
} |
563 | 564 |
|
564 | 565 |
///Executes the algorithm until a condition is met. |
565 | 566 |
|
566 | 567 |
///Executes the algorithm until a condition is met. |
567 | 568 |
/// |
568 | 569 |
///This method runs the %DFS algorithm from the root node |
569 | 570 |
///until an arc \c a with <tt>am[a]</tt> true is found. |
570 | 571 |
/// |
571 | 572 |
///\param am A \c bool (or convertible) arc map. The algorithm |
572 | 573 |
///will stop when it reaches an arc \c a with <tt>am[a]</tt> true. |
573 | 574 |
/// |
574 | 575 |
///\return The reached arc \c a with <tt>am[a]</tt> true or |
575 | 576 |
///\c INVALID if no such arc was found. |
576 | 577 |
/// |
577 | 578 |
///\pre init() must be called and a root node should be |
578 | 579 |
///added with addSource() before using this function. |
579 | 580 |
/// |
580 | 581 |
///\warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map, |
581 | 582 |
///not a node map. |
582 | 583 |
template<class ArcBoolMap> |
583 | 584 |
Arc start(const ArcBoolMap &am) |
584 | 585 |
{ |
585 | 586 |
while ( !emptyQueue() && !am[_stack[_stack_head]] ) |
586 | 587 |
processNextArc(); |
587 | 588 |
return emptyQueue() ? INVALID : _stack[_stack_head]; |
588 | 589 |
} |
589 | 590 |
|
590 | 591 |
///Runs the algorithm from the given source node. |
591 | 592 |
|
592 | 593 |
///This method runs the %DFS algorithm from node \c s |
593 | 594 |
///in order to compute the DFS path to each node. |
594 | 595 |
/// |
595 | 596 |
///The algorithm computes |
596 | 597 |
///- the %DFS tree, |
597 | 598 |
///- the distance of each node from the root in the %DFS tree. |
598 | 599 |
/// |
599 | 600 |
///\note <tt>d.run(s)</tt> is just a shortcut of the following code. |
600 | 601 |
///\code |
601 | 602 |
/// d.init(); |
602 | 603 |
/// d.addSource(s); |
603 | 604 |
/// d.start(); |
604 | 605 |
///\endcode |
605 | 606 |
void run(Node s) { |
606 | 607 |
init(); |
607 | 608 |
addSource(s); |
608 | 609 |
start(); |
609 | 610 |
} |
610 | 611 |
|
611 | 612 |
///Finds the %DFS path between \c s and \c t. |
612 | 613 |
|
613 | 614 |
///This method runs the %DFS algorithm from node \c s |
614 | 615 |
///in order to compute the DFS path to node \c t |
615 | 616 |
///(it stops searching when \c t is processed) |
616 | 617 |
/// |
617 | 618 |
///\return \c true if \c t is reachable form \c s. |
618 | 619 |
/// |
619 | 620 |
///\note Apart from the return value, <tt>d.run(s,t)</tt> is |
620 | 621 |
///just a shortcut of the following code. |
621 | 622 |
///\code |
622 | 623 |
/// d.init(); |
623 | 624 |
/// d.addSource(s); |
624 | 625 |
/// d.start(t); |
625 | 626 |
///\endcode |
626 | 627 |
bool run(Node s,Node t) { |
627 | 628 |
init(); |
628 | 629 |
addSource(s); |
629 | 630 |
start(t); |
630 | 631 |
return reached(t); |
631 | 632 |
} |
632 | 633 |
|
633 | 634 |
///Runs the algorithm to visit all nodes in the digraph. |
634 | 635 |
|
635 | 636 |
///This method runs the %DFS algorithm in order to compute the |
636 | 637 |
///%DFS path to each node. |
637 | 638 |
/// |
638 | 639 |
///The algorithm computes |
639 | 640 |
///- the %DFS tree (forest), |
640 | 641 |
///- the distance of each node from the root(s) in the %DFS tree. |
641 | 642 |
/// |
642 | 643 |
///\note <tt>d.run()</tt> is just a shortcut of the following code. |
643 | 644 |
///\code |
644 | 645 |
/// d.init(); |
645 | 646 |
/// for (NodeIt n(digraph); n != INVALID; ++n) { |
646 | 647 |
/// if (!d.reached(n)) { |
647 | 648 |
/// d.addSource(n); |
648 | 649 |
/// d.start(); |
649 | 650 |
/// } |
650 | 651 |
/// } |
651 | 652 |
///\endcode |
652 | 653 |
void run() { |
653 | 654 |
init(); |
654 | 655 |
for (NodeIt it(*G); it != INVALID; ++it) { |
655 | 656 |
if (!reached(it)) { |
656 | 657 |
addSource(it); |
657 | 658 |
start(); |
658 | 659 |
} |
659 | 660 |
} |
660 | 661 |
} |
661 | 662 |
|
662 | 663 |
///@} |
663 | 664 |
|
664 | 665 |
///\name Query Functions |
665 | 666 |
///The results of the DFS algorithm can be obtained using these |
666 | 667 |
///functions.\n |
667 | 668 |
///Either \ref run(Node) "run()" or \ref start() should be called |
668 | 669 |
///before using them. |
669 | 670 |
|
670 | 671 |
///@{ |
671 | 672 |
|
672 |
///The DFS path to |
|
673 |
///The DFS path to the given node. |
|
673 | 674 |
|
674 |
///Returns the DFS path to |
|
675 |
///Returns the DFS path to the given node from the root(s). |
|
675 | 676 |
/// |
676 | 677 |
///\warning \c t should be reached from the root(s). |
677 | 678 |
/// |
678 | 679 |
///\pre Either \ref run(Node) "run()" or \ref init() |
679 | 680 |
///must be called before using this function. |
680 | 681 |
Path path(Node t) const { return Path(*G, *_pred, t); } |
681 | 682 |
|
682 |
///The distance of |
|
683 |
///The distance of the given node from the root(s). |
|
683 | 684 |
|
684 |
///Returns the distance of |
|
685 |
///Returns the distance of the given node from the root(s). |
|
685 | 686 |
/// |
686 | 687 |
///\warning If node \c v is not reached from the root(s), then |
687 | 688 |
///the return value of this function is undefined. |
688 | 689 |
/// |
689 | 690 |
///\pre Either \ref run(Node) "run()" or \ref init() |
690 | 691 |
///must be called before using this function. |
691 | 692 |
int dist(Node v) const { return (*_dist)[v]; } |
692 | 693 |
|
693 |
///Returns the 'previous arc' of the %DFS tree for |
|
694 |
///Returns the 'previous arc' of the %DFS tree for the given node. |
|
694 | 695 |
|
695 | 696 |
///This function returns the 'previous arc' of the %DFS tree for the |
696 | 697 |
///node \c v, i.e. it returns the last arc of a %DFS path from a |
697 | 698 |
///root to \c v. It is \c INVALID if \c v is not reached from the |
698 | 699 |
///root(s) or if \c v is a root. |
699 | 700 |
/// |
700 | 701 |
///The %DFS tree used here is equal to the %DFS tree used in |
701 |
///\ref predNode(). |
|
702 |
///\ref predNode() and \ref predMap(). |
|
702 | 703 |
/// |
703 | 704 |
///\pre Either \ref run(Node) "run()" or \ref init() |
704 | 705 |
///must be called before using this function. |
705 | 706 |
Arc predArc(Node v) const { return (*_pred)[v];} |
706 | 707 |
|
707 |
///Returns the 'previous node' of the %DFS tree. |
|
708 |
///Returns the 'previous node' of the %DFS tree for the given node. |
|
708 | 709 |
|
709 | 710 |
///This function returns the 'previous node' of the %DFS |
710 | 711 |
///tree for the node \c v, i.e. it returns the last but one node |
711 |
/// |
|
712 |
///of a %DFS path from a root to \c v. It is \c INVALID |
|
712 | 713 |
///if \c v is not reached from the root(s) or if \c v is a root. |
713 | 714 |
/// |
714 | 715 |
///The %DFS tree used here is equal to the %DFS tree used in |
715 |
///\ref predArc(). |
|
716 |
///\ref predArc() and \ref predMap(). |
|
716 | 717 |
/// |
717 | 718 |
///\pre Either \ref run(Node) "run()" or \ref init() |
718 | 719 |
///must be called before using this function. |
719 | 720 |
Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
720 | 721 |
G->source((*_pred)[v]); } |
721 | 722 |
|
722 | 723 |
///\brief Returns a const reference to the node map that stores the |
723 | 724 |
///distances of the nodes. |
724 | 725 |
/// |
725 | 726 |
///Returns a const reference to the node map that stores the |
726 | 727 |
///distances of the nodes calculated by the algorithm. |
727 | 728 |
/// |
728 | 729 |
///\pre Either \ref run(Node) "run()" or \ref init() |
729 | 730 |
///must be called before using this function. |
730 | 731 |
const DistMap &distMap() const { return *_dist;} |
731 | 732 |
|
732 | 733 |
///\brief Returns a const reference to the node map that stores the |
733 | 734 |
///predecessor arcs. |
734 | 735 |
/// |
735 | 736 |
///Returns a const reference to the node map that stores the predecessor |
736 |
///arcs, which form the DFS tree. |
|
737 |
///arcs, which form the DFS tree (forest). |
|
737 | 738 |
/// |
738 | 739 |
///\pre Either \ref run(Node) "run()" or \ref init() |
739 | 740 |
///must be called before using this function. |
740 | 741 |
const PredMap &predMap() const { return *_pred;} |
741 | 742 |
|
742 |
///Checks if |
|
743 |
///Checks if the given node. node is reached from the root(s). |
|
743 | 744 |
|
744 | 745 |
///Returns \c true if \c v is reached from the root(s). |
745 | 746 |
/// |
746 | 747 |
///\pre Either \ref run(Node) "run()" or \ref init() |
747 | 748 |
///must be called before using this function. |
748 | 749 |
bool reached(Node v) const { return (*_reached)[v]; } |
749 | 750 |
|
750 | 751 |
///@} |
751 | 752 |
}; |
752 | 753 |
|
753 | 754 |
///Default traits class of dfs() function. |
754 | 755 |
|
755 | 756 |
///Default traits class of dfs() function. |
756 | 757 |
///\tparam GR Digraph type. |
757 | 758 |
template<class GR> |
758 | 759 |
struct DfsWizardDefaultTraits |
759 | 760 |
{ |
760 | 761 |
///The type of the digraph the algorithm runs on. |
761 | 762 |
typedef GR Digraph; |
762 | 763 |
|
763 | 764 |
///\brief The type of the map that stores the predecessor |
764 | 765 |
///arcs of the %DFS paths. |
765 | 766 |
/// |
766 | 767 |
///The type of the map that stores the predecessor |
767 | 768 |
///arcs of the %DFS paths. |
768 |
///It must |
|
769 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
769 | 770 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
770 | 771 |
///Instantiates a PredMap. |
771 | 772 |
|
772 | 773 |
///This function instantiates a PredMap. |
773 | 774 |
///\param g is the digraph, to which we would like to define the |
774 | 775 |
///PredMap. |
775 | 776 |
static PredMap *createPredMap(const Digraph &g) |
776 | 777 |
{ |
777 | 778 |
return new PredMap(g); |
778 | 779 |
} |
779 | 780 |
|
780 | 781 |
///The type of the map that indicates which nodes are processed. |
781 | 782 |
|
782 | 783 |
///The type of the map that indicates which nodes are processed. |
783 |
///It must |
|
784 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
784 | 785 |
///By default it is a NullMap. |
785 | 786 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
786 | 787 |
///Instantiates a ProcessedMap. |
787 | 788 |
|
788 | 789 |
///This function instantiates a ProcessedMap. |
789 | 790 |
///\param g is the digraph, to which |
790 | 791 |
///we would like to define the ProcessedMap. |
791 | 792 |
#ifdef DOXYGEN |
792 | 793 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
793 | 794 |
#else |
794 | 795 |
static ProcessedMap *createProcessedMap(const Digraph &) |
795 | 796 |
#endif |
796 | 797 |
{ |
797 | 798 |
return new ProcessedMap(); |
798 | 799 |
} |
799 | 800 |
|
800 | 801 |
///The type of the map that indicates which nodes are reached. |
801 | 802 |
|
802 | 803 |
///The type of the map that indicates which nodes are reached. |
803 |
///It must |
|
804 |
///It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
804 | 805 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
805 | 806 |
///Instantiates a ReachedMap. |
806 | 807 |
|
807 | 808 |
///This function instantiates a ReachedMap. |
808 | 809 |
///\param g is the digraph, to which |
809 | 810 |
///we would like to define the ReachedMap. |
810 | 811 |
static ReachedMap *createReachedMap(const Digraph &g) |
811 | 812 |
{ |
812 | 813 |
return new ReachedMap(g); |
813 | 814 |
} |
814 | 815 |
|
815 | 816 |
///The type of the map that stores the distances of the nodes. |
816 | 817 |
|
817 | 818 |
///The type of the map that stores the distances of the nodes. |
818 |
///It must |
|
819 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
819 | 820 |
typedef typename Digraph::template NodeMap<int> DistMap; |
820 | 821 |
///Instantiates a DistMap. |
821 | 822 |
|
822 | 823 |
///This function instantiates a DistMap. |
823 | 824 |
///\param g is the digraph, to which we would like to define |
824 | 825 |
///the DistMap |
825 | 826 |
static DistMap *createDistMap(const Digraph &g) |
826 | 827 |
{ |
827 | 828 |
return new DistMap(g); |
828 | 829 |
} |
829 | 830 |
|
830 | 831 |
///The type of the DFS paths. |
831 | 832 |
|
832 | 833 |
///The type of the DFS paths. |
833 |
///It must |
|
834 |
///It must conform to the \ref concepts::Path "Path" concept. |
|
834 | 835 |
typedef lemon::Path<Digraph> Path; |
835 | 836 |
}; |
836 | 837 |
|
837 | 838 |
/// Default traits class used by DfsWizard |
838 | 839 |
|
839 |
/// To make it easier to use Dfs algorithm |
|
840 |
/// we have created a wizard class. |
|
841 |
/// This \ref DfsWizard class needs default traits, |
|
842 |
/// as well as the \ref Dfs class. |
|
843 |
/// The \ref DfsWizardBase is a class to be the default traits of the |
|
844 |
/// \ref DfsWizard class. |
|
840 |
/// Default traits class used by DfsWizard. |
|
841 |
/// \tparam GR The type of the digraph. |
|
845 | 842 |
template<class GR> |
846 | 843 |
class DfsWizardBase : public DfsWizardDefaultTraits<GR> |
847 | 844 |
{ |
848 | 845 |
|
849 | 846 |
typedef DfsWizardDefaultTraits<GR> Base; |
850 | 847 |
protected: |
851 | 848 |
//The type of the nodes in the digraph. |
852 | 849 |
typedef typename Base::Digraph::Node Node; |
853 | 850 |
|
854 | 851 |
//Pointer to the digraph the algorithm runs on. |
855 | 852 |
void *_g; |
856 | 853 |
//Pointer to the map of reached nodes. |
857 | 854 |
void *_reached; |
858 | 855 |
//Pointer to the map of processed nodes. |
859 | 856 |
void *_processed; |
860 | 857 |
//Pointer to the map of predecessors arcs. |
861 | 858 |
void *_pred; |
862 | 859 |
//Pointer to the map of distances. |
863 | 860 |
void *_dist; |
864 | 861 |
//Pointer to the DFS path to the target node. |
865 | 862 |
void *_path; |
866 | 863 |
//Pointer to the distance of the target node. |
867 | 864 |
int *_di; |
868 | 865 |
|
869 | 866 |
public: |
870 | 867 |
/// Constructor. |
871 | 868 |
|
872 |
/// This constructor does not require parameters, |
|
869 |
/// This constructor does not require parameters, it initiates |
|
873 | 870 |
/// all of the attributes to \c 0. |
874 | 871 |
DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
875 | 872 |
_dist(0), _path(0), _di(0) {} |
876 | 873 |
|
877 | 874 |
/// Constructor. |
878 | 875 |
|
879 | 876 |
/// This constructor requires one parameter, |
880 | 877 |
/// others are initiated to \c 0. |
881 | 878 |
/// \param g The digraph the algorithm runs on. |
882 | 879 |
DfsWizardBase(const GR &g) : |
883 | 880 |
_g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
884 | 881 |
_reached(0), _processed(0), _pred(0), _dist(0), _path(0), _di(0) {} |
885 | 882 |
|
886 | 883 |
}; |
887 | 884 |
|
888 | 885 |
/// Auxiliary class for the function-type interface of DFS algorithm. |
889 | 886 |
|
890 | 887 |
/// This auxiliary class is created to implement the |
891 | 888 |
/// \ref dfs() "function-type interface" of \ref Dfs algorithm. |
892 | 889 |
/// It does not have own \ref run(Node) "run()" method, it uses the |
893 | 890 |
/// functions and features of the plain \ref Dfs. |
894 | 891 |
/// |
895 | 892 |
/// This class should only be used through the \ref dfs() function, |
896 | 893 |
/// which makes it easier to use the algorithm. |
897 | 894 |
template<class TR> |
898 | 895 |
class DfsWizard : public TR |
899 | 896 |
{ |
900 | 897 |
typedef TR Base; |
901 | 898 |
|
902 |
///The type of the digraph the algorithm runs on. |
|
903 | 899 |
typedef typename TR::Digraph Digraph; |
904 | 900 |
|
905 | 901 |
typedef typename Digraph::Node Node; |
906 | 902 |
typedef typename Digraph::NodeIt NodeIt; |
907 | 903 |
typedef typename Digraph::Arc Arc; |
908 | 904 |
typedef typename Digraph::OutArcIt OutArcIt; |
909 | 905 |
|
910 |
///\brief The type of the map that stores the predecessor |
|
911 |
///arcs of the DFS paths. |
|
912 | 906 |
typedef typename TR::PredMap PredMap; |
913 |
///\brief The type of the map that stores the distances of the nodes. |
|
914 | 907 |
typedef typename TR::DistMap DistMap; |
915 |
///\brief The type of the map that indicates which nodes are reached. |
|
916 | 908 |
typedef typename TR::ReachedMap ReachedMap; |
917 |
///\brief The type of the map that indicates which nodes are processed. |
|
918 | 909 |
typedef typename TR::ProcessedMap ProcessedMap; |
919 |
///The type of the DFS paths |
|
920 | 910 |
typedef typename TR::Path Path; |
921 | 911 |
|
922 | 912 |
public: |
923 | 913 |
|
924 | 914 |
/// Constructor. |
925 | 915 |
DfsWizard() : TR() {} |
926 | 916 |
|
927 | 917 |
/// Constructor that requires parameters. |
928 | 918 |
|
929 | 919 |
/// Constructor that requires parameters. |
930 | 920 |
/// These parameters will be the default values for the traits class. |
931 | 921 |
/// \param g The digraph the algorithm runs on. |
932 | 922 |
DfsWizard(const Digraph &g) : |
933 | 923 |
TR(g) {} |
934 | 924 |
|
935 | 925 |
///Copy constructor |
936 | 926 |
DfsWizard(const TR &b) : TR(b) {} |
937 | 927 |
|
938 | 928 |
~DfsWizard() {} |
939 | 929 |
|
940 | 930 |
///Runs DFS algorithm from the given source node. |
941 | 931 |
|
942 | 932 |
///This method runs DFS algorithm from node \c s |
943 | 933 |
///in order to compute the DFS path to each node. |
944 | 934 |
void run(Node s) |
945 | 935 |
{ |
946 | 936 |
Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g)); |
947 | 937 |
if (Base::_pred) |
948 | 938 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
949 | 939 |
if (Base::_dist) |
950 | 940 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
951 | 941 |
if (Base::_reached) |
952 | 942 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
953 | 943 |
if (Base::_processed) |
954 | 944 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
955 | 945 |
if (s!=INVALID) |
956 | 946 |
alg.run(s); |
957 | 947 |
else |
958 | 948 |
alg.run(); |
959 | 949 |
} |
960 | 950 |
|
961 | 951 |
///Finds the DFS path between \c s and \c t. |
962 | 952 |
|
963 | 953 |
///This method runs DFS algorithm from node \c s |
964 | 954 |
///in order to compute the DFS path to node \c t |
965 | 955 |
///(it stops searching when \c t is processed). |
966 | 956 |
/// |
967 | 957 |
///\return \c true if \c t is reachable form \c s. |
968 | 958 |
bool run(Node s, Node t) |
969 | 959 |
{ |
970 | 960 |
Dfs<Digraph,TR> alg(*reinterpret_cast<const Digraph*>(Base::_g)); |
971 | 961 |
if (Base::_pred) |
972 | 962 |
alg.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
973 | 963 |
if (Base::_dist) |
974 | 964 |
alg.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
975 | 965 |
if (Base::_reached) |
976 | 966 |
alg.reachedMap(*reinterpret_cast<ReachedMap*>(Base::_reached)); |
977 | 967 |
if (Base::_processed) |
978 | 968 |
alg.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
979 | 969 |
alg.run(s,t); |
980 | 970 |
if (Base::_path) |
981 | 971 |
*reinterpret_cast<Path*>(Base::_path) = alg.path(t); |
982 | 972 |
if (Base::_di) |
983 | 973 |
*Base::_di = alg.dist(t); |
984 | 974 |
return alg.reached(t); |
985 | 975 |
} |
986 | 976 |
|
987 | 977 |
///Runs DFS algorithm to visit all nodes in the digraph. |
988 | 978 |
|
989 | 979 |
///This method runs DFS algorithm in order to compute |
990 | 980 |
///the DFS path to each node. |
991 | 981 |
void run() |
992 | 982 |
{ |
993 | 983 |
run(INVALID); |
994 | 984 |
} |
995 | 985 |
|
996 | 986 |
template<class T> |
997 | 987 |
struct SetPredMapBase : public Base { |
998 | 988 |
typedef T PredMap; |
999 | 989 |
static PredMap *createPredMap(const Digraph &) { return 0; }; |
1000 | 990 |
SetPredMapBase(const TR &b) : TR(b) {} |
1001 | 991 |
}; |
1002 |
///\brief \ref named-func-param "Named parameter" |
|
1003 |
///for setting PredMap object. |
|
992 |
|
|
993 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
994 |
///the predecessor map. |
|
1004 | 995 |
/// |
1005 |
///\ref named-func-param "Named parameter" |
|
1006 |
///for setting PredMap object. |
|
996 |
///\ref named-templ-param "Named parameter" function for setting |
|
997 |
///the map that stores the predecessor arcs of the nodes. |
|
1007 | 998 |
template<class T> |
1008 | 999 |
DfsWizard<SetPredMapBase<T> > predMap(const T &t) |
1009 | 1000 |
{ |
1010 | 1001 |
Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1011 | 1002 |
return DfsWizard<SetPredMapBase<T> >(*this); |
1012 | 1003 |
} |
1013 | 1004 |
|
1014 | 1005 |
template<class T> |
1015 | 1006 |
struct SetReachedMapBase : public Base { |
1016 | 1007 |
typedef T ReachedMap; |
1017 | 1008 |
static ReachedMap *createReachedMap(const Digraph &) { return 0; }; |
1018 | 1009 |
SetReachedMapBase(const TR &b) : TR(b) {} |
1019 | 1010 |
}; |
1020 |
///\brief \ref named-func-param "Named parameter" |
|
1021 |
///for setting ReachedMap object. |
|
1011 |
|
|
1012 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1013 |
///the reached map. |
|
1022 | 1014 |
/// |
1023 |
/// \ref named-func-param "Named parameter" |
|
1024 |
///for setting ReachedMap object. |
|
1015 |
///\ref named-templ-param "Named parameter" function for setting |
|
1016 |
///the map that indicates which nodes are reached. |
|
1025 | 1017 |
template<class T> |
1026 | 1018 |
DfsWizard<SetReachedMapBase<T> > reachedMap(const T &t) |
1027 | 1019 |
{ |
1028 | 1020 |
Base::_reached=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1029 | 1021 |
return DfsWizard<SetReachedMapBase<T> >(*this); |
1030 | 1022 |
} |
1031 | 1023 |
|
1032 | 1024 |
template<class T> |
1033 | 1025 |
struct SetDistMapBase : public Base { |
1034 | 1026 |
typedef T DistMap; |
1035 | 1027 |
static DistMap *createDistMap(const Digraph &) { return 0; }; |
1036 | 1028 |
SetDistMapBase(const TR &b) : TR(b) {} |
1037 | 1029 |
}; |
1038 |
///\brief \ref named-func-param "Named parameter" |
|
1039 |
///for setting DistMap object. |
|
1030 |
|
|
1031 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1032 |
///the distance map. |
|
1040 | 1033 |
/// |
1041 |
/// \ref named-func-param "Named parameter" |
|
1042 |
///for setting DistMap object. |
|
1034 |
///\ref named-templ-param "Named parameter" function for setting |
|
1035 |
///the map that stores the distances of the nodes calculated |
|
1036 |
///by the algorithm. |
|
1043 | 1037 |
template<class T> |
1044 | 1038 |
DfsWizard<SetDistMapBase<T> > distMap(const T &t) |
1045 | 1039 |
{ |
1046 | 1040 |
Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1047 | 1041 |
return DfsWizard<SetDistMapBase<T> >(*this); |
1048 | 1042 |
} |
1049 | 1043 |
|
1050 | 1044 |
template<class T> |
1051 | 1045 |
struct SetProcessedMapBase : public Base { |
1052 | 1046 |
typedef T ProcessedMap; |
1053 | 1047 |
static ProcessedMap *createProcessedMap(const Digraph &) { return 0; }; |
1054 | 1048 |
SetProcessedMapBase(const TR &b) : TR(b) {} |
1055 | 1049 |
}; |
1056 |
///\brief \ref named-func-param "Named parameter" |
|
1057 |
///for setting ProcessedMap object. |
|
1050 |
|
|
1051 |
///\brief \ref named-func-param "Named parameter" for setting |
|
1052 |
///the processed map. |
|
1058 | 1053 |
/// |
1059 |
/// \ref named-func-param "Named parameter" |
|
1060 |
///for setting ProcessedMap object. |
|
1054 |
///\ref named-templ-param "Named parameter" function for setting |
|
1055 |
///the map that indicates which nodes are processed. |
|
1061 | 1056 |
template<class T> |
1062 | 1057 |
DfsWizard<SetProcessedMapBase<T> > processedMap(const T &t) |
1063 | 1058 |
{ |
1064 | 1059 |
Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1065 | 1060 |
return DfsWizard<SetProcessedMapBase<T> >(*this); |
1066 | 1061 |
} |
1067 | 1062 |
|
1068 | 1063 |
template<class T> |
1069 | 1064 |
struct SetPathBase : public Base { |
1070 | 1065 |
typedef T Path; |
1071 | 1066 |
SetPathBase(const TR &b) : TR(b) {} |
1072 | 1067 |
}; |
1073 | 1068 |
///\brief \ref named-func-param "Named parameter" |
1074 | 1069 |
///for getting the DFS path to the target node. |
1075 | 1070 |
/// |
1076 | 1071 |
///\ref named-func-param "Named parameter" |
1077 | 1072 |
///for getting the DFS path to the target node. |
1078 | 1073 |
template<class T> |
1079 | 1074 |
DfsWizard<SetPathBase<T> > path(const T &t) |
1080 | 1075 |
{ |
1081 | 1076 |
Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1082 | 1077 |
return DfsWizard<SetPathBase<T> >(*this); |
1083 | 1078 |
} |
1084 | 1079 |
|
1085 | 1080 |
///\brief \ref named-func-param "Named parameter" |
1086 | 1081 |
///for getting the distance of the target node. |
1087 | 1082 |
/// |
1088 | 1083 |
///\ref named-func-param "Named parameter" |
1089 | 1084 |
///for getting the distance of the target node. |
1090 | 1085 |
DfsWizard dist(const int &d) |
1091 | 1086 |
{ |
1092 | 1087 |
Base::_di=const_cast<int*>(&d); |
1093 | 1088 |
return *this; |
1094 | 1089 |
} |
1095 | 1090 |
|
1096 | 1091 |
}; |
1097 | 1092 |
|
1098 | 1093 |
///Function-type interface for DFS algorithm. |
1099 | 1094 |
|
1100 | 1095 |
///\ingroup search |
1101 | 1096 |
///Function-type interface for DFS algorithm. |
1102 | 1097 |
/// |
1103 | 1098 |
///This function also has several \ref named-func-param "named parameters", |
1104 | 1099 |
///they are declared as the members of class \ref DfsWizard. |
1105 | 1100 |
///The following examples show how to use these parameters. |
1106 | 1101 |
///\code |
1107 | 1102 |
/// // Compute the DFS tree |
1108 | 1103 |
/// dfs(g).predMap(preds).distMap(dists).run(s); |
1109 | 1104 |
/// |
1110 | 1105 |
/// // Compute the DFS path from s to t |
1111 | 1106 |
/// bool reached = dfs(g).path(p).dist(d).run(s,t); |
1112 | 1107 |
///\endcode |
1113 | 1108 |
///\warning Don't forget to put the \ref DfsWizard::run(Node) "run()" |
1114 | 1109 |
///to the end of the parameter list. |
1115 | 1110 |
///\sa DfsWizard |
1116 | 1111 |
///\sa Dfs |
1117 | 1112 |
template<class GR> |
1118 | 1113 |
DfsWizard<DfsWizardBase<GR> > |
1119 | 1114 |
dfs(const GR &digraph) |
1120 | 1115 |
{ |
1121 | 1116 |
return DfsWizard<DfsWizardBase<GR> >(digraph); |
1122 | 1117 |
} |
1123 | 1118 |
|
1124 | 1119 |
#ifdef DOXYGEN |
1125 | 1120 |
/// \brief Visitor class for DFS. |
1126 | 1121 |
/// |
1127 | 1122 |
/// This class defines the interface of the DfsVisit events, and |
1128 | 1123 |
/// it could be the base of a real visitor class. |
1129 | 1124 |
template <typename GR> |
1130 | 1125 |
struct DfsVisitor { |
1131 | 1126 |
typedef GR Digraph; |
1132 | 1127 |
typedef typename Digraph::Arc Arc; |
1133 | 1128 |
typedef typename Digraph::Node Node; |
1134 | 1129 |
/// \brief Called for the source node of the DFS. |
1135 | 1130 |
/// |
1136 | 1131 |
/// This function is called for the source node of the DFS. |
1137 | 1132 |
void start(const Node& node) {} |
1138 | 1133 |
/// \brief Called when the source node is leaved. |
1139 | 1134 |
/// |
1140 | 1135 |
/// This function is called when the source node is leaved. |
1141 | 1136 |
void stop(const Node& node) {} |
1142 | 1137 |
/// \brief Called when a node is reached first time. |
1143 | 1138 |
/// |
1144 | 1139 |
/// This function is called when a node is reached first time. |
1145 | 1140 |
void reach(const Node& node) {} |
1146 | 1141 |
/// \brief Called when an arc reaches a new node. |
1147 | 1142 |
/// |
1148 | 1143 |
/// This function is called when the DFS finds an arc whose target node |
1149 | 1144 |
/// is not reached yet. |
1150 | 1145 |
void discover(const Arc& arc) {} |
1151 | 1146 |
/// \brief Called when an arc is examined but its target node is |
1152 | 1147 |
/// already discovered. |
1153 | 1148 |
/// |
1154 | 1149 |
/// This function is called when an arc is examined but its target node is |
1155 | 1150 |
/// already discovered. |
1156 | 1151 |
void examine(const Arc& arc) {} |
1157 | 1152 |
/// \brief Called when the DFS steps back from a node. |
1158 | 1153 |
/// |
1159 | 1154 |
/// This function is called when the DFS steps back from a node. |
1160 | 1155 |
void leave(const Node& node) {} |
1161 | 1156 |
/// \brief Called when the DFS steps back on an arc. |
1162 | 1157 |
/// |
1163 | 1158 |
/// This function is called when the DFS steps back on an arc. |
1164 | 1159 |
void backtrack(const Arc& arc) {} |
1165 | 1160 |
}; |
1166 | 1161 |
#else |
1167 | 1162 |
template <typename GR> |
1168 | 1163 |
struct DfsVisitor { |
1169 | 1164 |
typedef GR Digraph; |
1170 | 1165 |
typedef typename Digraph::Arc Arc; |
1171 | 1166 |
typedef typename Digraph::Node Node; |
1172 | 1167 |
void start(const Node&) {} |
1173 | 1168 |
void stop(const Node&) {} |
1174 | 1169 |
void reach(const Node&) {} |
1175 | 1170 |
void discover(const Arc&) {} |
1176 | 1171 |
void examine(const Arc&) {} |
1177 | 1172 |
void leave(const Node&) {} |
1178 | 1173 |
void backtrack(const Arc&) {} |
1179 | 1174 |
|
1180 | 1175 |
template <typename _Visitor> |
1181 | 1176 |
struct Constraints { |
1182 | 1177 |
void constraints() { |
1183 | 1178 |
Arc arc; |
1184 | 1179 |
Node node; |
1185 | 1180 |
visitor.start(node); |
1186 | 1181 |
visitor.stop(arc); |
1187 | 1182 |
visitor.reach(node); |
1188 | 1183 |
visitor.discover(arc); |
1189 | 1184 |
visitor.examine(arc); |
1190 | 1185 |
visitor.leave(node); |
1191 | 1186 |
visitor.backtrack(arc); |
1192 | 1187 |
} |
1193 | 1188 |
_Visitor& visitor; |
1194 | 1189 |
}; |
1195 | 1190 |
}; |
1196 | 1191 |
#endif |
1197 | 1192 |
|
1198 | 1193 |
/// \brief Default traits class of DfsVisit class. |
1199 | 1194 |
/// |
1200 | 1195 |
/// Default traits class of DfsVisit class. |
1201 | 1196 |
/// \tparam _Digraph The type of the digraph the algorithm runs on. |
1202 | 1197 |
template<class GR> |
1203 | 1198 |
struct DfsVisitDefaultTraits { |
1204 | 1199 |
|
1205 | 1200 |
/// \brief The type of the digraph the algorithm runs on. |
1206 | 1201 |
typedef GR Digraph; |
1207 | 1202 |
|
1208 | 1203 |
/// \brief The type of the map that indicates which nodes are reached. |
1209 | 1204 |
/// |
1210 | 1205 |
/// The type of the map that indicates which nodes are reached. |
1211 |
/// It must |
|
1206 |
/// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
|
1212 | 1207 |
typedef typename Digraph::template NodeMap<bool> ReachedMap; |
1213 | 1208 |
|
1214 | 1209 |
/// \brief Instantiates a ReachedMap. |
1215 | 1210 |
/// |
1216 | 1211 |
/// This function instantiates a ReachedMap. |
1217 | 1212 |
/// \param digraph is the digraph, to which |
1218 | 1213 |
/// we would like to define the ReachedMap. |
1219 | 1214 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1220 | 1215 |
return new ReachedMap(digraph); |
1221 | 1216 |
} |
1222 | 1217 |
|
1223 | 1218 |
}; |
1224 | 1219 |
|
1225 | 1220 |
/// \ingroup search |
1226 | 1221 |
/// |
1227 | 1222 |
/// \brief DFS algorithm class with visitor interface. |
1228 | 1223 |
/// |
1229 | 1224 |
/// This class provides an efficient implementation of the DFS algorithm |
1230 | 1225 |
/// with visitor interface. |
1231 | 1226 |
/// |
1232 | 1227 |
/// The DfsVisit class provides an alternative interface to the Dfs |
1233 | 1228 |
/// class. It works with callback mechanism, the DfsVisit object calls |
1234 | 1229 |
/// the member functions of the \c Visitor class on every DFS event. |
1235 | 1230 |
/// |
1236 | 1231 |
/// This interface of the DFS algorithm should be used in special cases |
1237 | 1232 |
/// when extra actions have to be performed in connection with certain |
1238 | 1233 |
/// events of the DFS algorithm. Otherwise consider to use Dfs or dfs() |
1239 | 1234 |
/// instead. |
1240 | 1235 |
/// |
1241 | 1236 |
/// \tparam GR The type of the digraph the algorithm runs on. |
1242 | 1237 |
/// The default type is \ref ListDigraph. |
1243 | 1238 |
/// The value of GR is not used directly by \ref DfsVisit, |
1244 | 1239 |
/// it is only passed to \ref DfsVisitDefaultTraits. |
1245 | 1240 |
/// \tparam VS The Visitor type that is used by the algorithm. |
1246 | 1241 |
/// \ref DfsVisitor "DfsVisitor<GR>" is an empty visitor, which |
1247 | 1242 |
/// does not observe the DFS events. If you want to observe the DFS |
1248 | 1243 |
/// events, you should implement your own visitor class. |
1249 | 1244 |
/// \tparam TR Traits class to set various data types used by the |
1250 | 1245 |
/// algorithm. The default traits class is |
1251 | 1246 |
/// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<GR>". |
1252 | 1247 |
/// See \ref DfsVisitDefaultTraits for the documentation of |
1253 | 1248 |
/// a DFS visit traits class. |
1254 | 1249 |
#ifdef DOXYGEN |
1255 | 1250 |
template <typename GR, typename VS, typename TR> |
1256 | 1251 |
#else |
1257 | 1252 |
template <typename GR = ListDigraph, |
1258 | 1253 |
typename VS = DfsVisitor<GR>, |
1259 | 1254 |
typename TR = DfsVisitDefaultTraits<GR> > |
1260 | 1255 |
#endif |
1261 | 1256 |
class DfsVisit { |
1262 | 1257 |
public: |
1263 | 1258 |
|
1264 | 1259 |
///The traits class. |
1265 | 1260 |
typedef TR Traits; |
1266 | 1261 |
|
1267 | 1262 |
///The type of the digraph the algorithm runs on. |
1268 | 1263 |
typedef typename Traits::Digraph Digraph; |
1269 | 1264 |
|
1270 | 1265 |
///The visitor type used by the algorithm. |
1271 | 1266 |
typedef VS Visitor; |
1272 | 1267 |
|
1273 | 1268 |
///The type of the map that indicates which nodes are reached. |
1274 | 1269 |
typedef typename Traits::ReachedMap ReachedMap; |
1275 | 1270 |
|
1276 | 1271 |
private: |
1277 | 1272 |
|
1278 | 1273 |
typedef typename Digraph::Node Node; |
1279 | 1274 |
typedef typename Digraph::NodeIt NodeIt; |
1280 | 1275 |
typedef typename Digraph::Arc Arc; |
1281 | 1276 |
typedef typename Digraph::OutArcIt OutArcIt; |
1282 | 1277 |
|
1283 | 1278 |
//Pointer to the underlying digraph. |
1284 | 1279 |
const Digraph *_digraph; |
1285 | 1280 |
//Pointer to the visitor object. |
1286 | 1281 |
Visitor *_visitor; |
1287 | 1282 |
//Pointer to the map of reached status of the nodes. |
1288 | 1283 |
ReachedMap *_reached; |
1289 | 1284 |
//Indicates if _reached is locally allocated (true) or not. |
1290 | 1285 |
bool local_reached; |
1291 | 1286 |
|
1292 | 1287 |
std::vector<typename Digraph::Arc> _stack; |
1293 | 1288 |
int _stack_head; |
1294 | 1289 |
|
1295 | 1290 |
//Creates the maps if necessary. |
1296 | 1291 |
void create_maps() { |
1297 | 1292 |
if(!_reached) { |
1298 | 1293 |
local_reached = true; |
1299 | 1294 |
_reached = Traits::createReachedMap(*_digraph); |
1300 | 1295 |
} |
1301 | 1296 |
} |
1302 | 1297 |
|
1303 | 1298 |
protected: |
1304 | 1299 |
|
1305 | 1300 |
DfsVisit() {} |
1306 | 1301 |
|
1307 | 1302 |
public: |
1308 | 1303 |
|
1309 | 1304 |
typedef DfsVisit Create; |
1310 | 1305 |
|
1311 | 1306 |
/// \name Named Template Parameters |
1312 | 1307 |
|
1313 | 1308 |
///@{ |
1314 | 1309 |
template <class T> |
1315 | 1310 |
struct SetReachedMapTraits : public Traits { |
1316 | 1311 |
typedef T ReachedMap; |
1317 | 1312 |
static ReachedMap *createReachedMap(const Digraph &digraph) { |
1318 | 1313 |
LEMON_ASSERT(false, "ReachedMap is not initialized"); |
1319 | 1314 |
return 0; // ignore warnings |
1320 | 1315 |
} |
1321 | 1316 |
}; |
1322 | 1317 |
/// \brief \ref named-templ-param "Named parameter" for setting |
1323 | 1318 |
/// ReachedMap type. |
1324 | 1319 |
/// |
1325 | 1320 |
/// \ref named-templ-param "Named parameter" for setting ReachedMap type. |
1326 | 1321 |
template <class T> |
1327 | 1322 |
struct SetReachedMap : public DfsVisit< Digraph, Visitor, |
1328 | 1323 |
SetReachedMapTraits<T> > { |
1329 | 1324 |
typedef DfsVisit< Digraph, Visitor, SetReachedMapTraits<T> > Create; |
1330 | 1325 |
}; |
1331 | 1326 |
///@} |
1332 | 1327 |
|
1333 | 1328 |
public: |
1334 | 1329 |
|
1335 | 1330 |
/// \brief Constructor. |
1336 | 1331 |
/// |
1337 | 1332 |
/// Constructor. |
1338 | 1333 |
/// |
1339 | 1334 |
/// \param digraph The digraph the algorithm runs on. |
1340 | 1335 |
/// \param visitor The visitor object of the algorithm. |
1341 | 1336 |
DfsVisit(const Digraph& digraph, Visitor& visitor) |
1342 | 1337 |
: _digraph(&digraph), _visitor(&visitor), |
1343 | 1338 |
_reached(0), local_reached(false) {} |
1344 | 1339 |
|
1345 | 1340 |
/// \brief Destructor. |
1346 | 1341 |
~DfsVisit() { |
1347 | 1342 |
if(local_reached) delete _reached; |
1348 | 1343 |
} |
1349 | 1344 |
|
1350 | 1345 |
/// \brief Sets the map that indicates which nodes are reached. |
1351 | 1346 |
/// |
1352 | 1347 |
/// Sets the map that indicates which nodes are reached. |
1353 | 1348 |
/// If you don't use this function before calling \ref run(Node) "run()" |
1354 | 1349 |
/// or \ref init(), an instance will be allocated automatically. |
1355 | 1350 |
/// The destructor deallocates this automatically allocated map, |
1356 | 1351 |
/// of course. |
1357 | 1352 |
/// \return <tt> (*this) </tt> |
1358 | 1353 |
DfsVisit &reachedMap(ReachedMap &m) { |
1359 | 1354 |
if(local_reached) { |
1360 | 1355 |
delete _reached; |
1361 | 1356 |
local_reached=false; |
1362 | 1357 |
} |
1363 | 1358 |
_reached = &m; |
1364 | 1359 |
return *this; |
1365 | 1360 |
} |
1366 | 1361 |
|
1367 | 1362 |
public: |
1368 | 1363 |
|
1369 | 1364 |
/// \name Execution Control |
1370 | 1365 |
/// The simplest way to execute the DFS algorithm is to use one of the |
1371 | 1366 |
/// member functions called \ref run(Node) "run()".\n |
1372 |
/// If you need more control on the execution, first you have to call |
|
1373 |
/// \ref init(), then you can add a source node with \ref addSource() |
|
1367 |
/// If you need better control on the execution, you have to call |
|
1368 |
/// \ref init() first, then you can add a source node with \ref addSource() |
|
1374 | 1369 |
/// and perform the actual computation with \ref start(). |
1375 | 1370 |
/// This procedure can be repeated if there are nodes that have not |
1376 | 1371 |
/// been reached. |
1377 | 1372 |
|
1378 | 1373 |
/// @{ |
1379 | 1374 |
|
1380 | 1375 |
/// \brief Initializes the internal data structures. |
1381 | 1376 |
/// |
1382 | 1377 |
/// Initializes the internal data structures. |
1383 | 1378 |
void init() { |
1384 | 1379 |
create_maps(); |
1385 | 1380 |
_stack.resize(countNodes(*_digraph)); |
1386 | 1381 |
_stack_head = -1; |
1387 | 1382 |
for (NodeIt u(*_digraph) ; u != INVALID ; ++u) { |
1388 | 1383 |
_reached->set(u, false); |
1389 | 1384 |
} |
1390 | 1385 |
} |
1391 | 1386 |
|
1392 | 1387 |
/// \brief Adds a new source node. |
1393 | 1388 |
/// |
1394 | 1389 |
/// Adds a new source node to the set of nodes to be processed. |
1395 | 1390 |
/// |
1396 | 1391 |
/// \pre The stack must be empty. Otherwise the algorithm gives |
1397 | 1392 |
/// wrong results. (One of the outgoing arcs of all the source nodes |
1398 | 1393 |
/// except for the last one will not be visited and distances will |
1399 | 1394 |
/// also be wrong.) |
1400 | 1395 |
void addSource(Node s) |
1401 | 1396 |
{ |
1402 | 1397 |
LEMON_DEBUG(emptyQueue(), "The stack is not empty."); |
1403 | 1398 |
if(!(*_reached)[s]) { |
1404 | 1399 |
_reached->set(s,true); |
1405 | 1400 |
_visitor->start(s); |
1406 | 1401 |
_visitor->reach(s); |
1407 | 1402 |
Arc e; |
1408 | 1403 |
_digraph->firstOut(e, s); |
1409 | 1404 |
if (e != INVALID) { |
1410 | 1405 |
_stack[++_stack_head] = e; |
1411 | 1406 |
} else { |
1412 | 1407 |
_visitor->leave(s); |
1413 | 1408 |
_visitor->stop(s); |
1414 | 1409 |
} |
1415 | 1410 |
} |
1416 | 1411 |
} |
1417 | 1412 |
|
1418 | 1413 |
/// \brief Processes the next arc. |
1419 | 1414 |
/// |
1420 | 1415 |
/// Processes the next arc. |
1421 | 1416 |
/// |
1422 | 1417 |
/// \return The processed arc. |
1423 | 1418 |
/// |
1424 | 1419 |
/// \pre The stack must not be empty. |
1425 | 1420 |
Arc processNextArc() { |
1426 | 1421 |
Arc e = _stack[_stack_head]; |
1427 | 1422 |
Node m = _digraph->target(e); |
1428 | 1423 |
if(!(*_reached)[m]) { |
1429 | 1424 |
_visitor->discover(e); |
1430 | 1425 |
_visitor->reach(m); |
1431 | 1426 |
_reached->set(m, true); |
1432 | 1427 |
_digraph->firstOut(_stack[++_stack_head], m); |
1433 | 1428 |
} else { |
1434 | 1429 |
_visitor->examine(e); |
1435 | 1430 |
m = _digraph->source(e); |
1436 | 1431 |
_digraph->nextOut(_stack[_stack_head]); |
1437 | 1432 |
} |
1438 | 1433 |
while (_stack_head>=0 && _stack[_stack_head] == INVALID) { |
1439 | 1434 |
_visitor->leave(m); |
1440 | 1435 |
--_stack_head; |
1441 | 1436 |
if (_stack_head >= 0) { |
1442 | 1437 |
_visitor->backtrack(_stack[_stack_head]); |
1443 | 1438 |
m = _digraph->source(_stack[_stack_head]); |
1444 | 1439 |
_digraph->nextOut(_stack[_stack_head]); |
1445 | 1440 |
} else { |
1446 | 1441 |
_visitor->stop(m); |
1447 | 1442 |
} |
1448 | 1443 |
} |
1449 | 1444 |
return e; |
1450 | 1445 |
} |
1451 | 1446 |
|
1452 | 1447 |
/// \brief Next arc to be processed. |
1453 | 1448 |
/// |
1454 | 1449 |
/// Next arc to be processed. |
1455 | 1450 |
/// |
1456 | 1451 |
/// \return The next arc to be processed or INVALID if the stack is |
1457 | 1452 |
/// empty. |
1458 | 1453 |
Arc nextArc() const { |
1459 | 1454 |
return _stack_head >= 0 ? _stack[_stack_head] : INVALID; |
1460 | 1455 |
} |
1461 | 1456 |
|
1462 | 1457 |
/// \brief Returns \c false if there are nodes |
1463 | 1458 |
/// to be processed. |
1464 | 1459 |
/// |
1465 | 1460 |
/// Returns \c false if there are nodes |
1466 | 1461 |
/// to be processed in the queue (stack). |
1467 | 1462 |
bool emptyQueue() const { return _stack_head < 0; } |
1468 | 1463 |
|
1469 | 1464 |
/// \brief Returns the number of the nodes to be processed. |
1470 | 1465 |
/// |
1471 | 1466 |
/// Returns the number of the nodes to be processed in the queue (stack). |
1472 | 1467 |
int queueSize() const { return _stack_head + 1; } |
1473 | 1468 |
|
1474 | 1469 |
/// \brief Executes the algorithm. |
1475 | 1470 |
/// |
1476 | 1471 |
/// Executes the algorithm. |
1477 | 1472 |
/// |
1478 | 1473 |
/// This method runs the %DFS algorithm from the root node |
1479 | 1474 |
/// in order to compute the %DFS path to each node. |
1480 | 1475 |
/// |
1481 | 1476 |
/// The algorithm computes |
1482 | 1477 |
/// - the %DFS tree, |
1483 | 1478 |
/// - the distance of each node from the root in the %DFS tree. |
1484 | 1479 |
/// |
1485 | 1480 |
/// \pre init() must be called and a root node should be |
1486 | 1481 |
/// added with addSource() before using this function. |
1487 | 1482 |
/// |
1488 | 1483 |
/// \note <tt>d.start()</tt> is just a shortcut of the following code. |
1489 | 1484 |
/// \code |
1490 | 1485 |
/// while ( !d.emptyQueue() ) { |
1491 | 1486 |
/// d.processNextArc(); |
1492 | 1487 |
/// } |
1493 | 1488 |
/// \endcode |
1494 | 1489 |
void start() { |
1495 | 1490 |
while ( !emptyQueue() ) processNextArc(); |
1496 | 1491 |
} |
1497 | 1492 |
|
1498 | 1493 |
/// \brief Executes the algorithm until the given target node is reached. |
1499 | 1494 |
/// |
1500 | 1495 |
/// Executes the algorithm until the given target node is reached. |
1501 | 1496 |
/// |
1502 | 1497 |
/// This method runs the %DFS algorithm from the root node |
1503 | 1498 |
/// in order to compute the DFS path to \c t. |
1504 | 1499 |
/// |
1505 | 1500 |
/// The algorithm computes |
1506 | 1501 |
/// - the %DFS path to \c t, |
1507 | 1502 |
/// - the distance of \c t from the root in the %DFS tree. |
1508 | 1503 |
/// |
1509 | 1504 |
/// \pre init() must be called and a root node should be added |
1510 | 1505 |
/// with addSource() before using this function. |
1511 | 1506 |
void start(Node t) { |
1512 | 1507 |
while ( !emptyQueue() && _digraph->target(_stack[_stack_head]) != t ) |
1513 | 1508 |
processNextArc(); |
1514 | 1509 |
} |
1515 | 1510 |
|
1516 | 1511 |
/// \brief Executes the algorithm until a condition is met. |
1517 | 1512 |
/// |
1518 | 1513 |
/// Executes the algorithm until a condition is met. |
1519 | 1514 |
/// |
1520 | 1515 |
/// This method runs the %DFS algorithm from the root node |
1521 | 1516 |
/// until an arc \c a with <tt>am[a]</tt> true is found. |
1522 | 1517 |
/// |
1523 | 1518 |
/// \param am A \c bool (or convertible) arc map. The algorithm |
1524 | 1519 |
/// will stop when it reaches an arc \c a with <tt>am[a]</tt> true. |
1525 | 1520 |
/// |
1526 | 1521 |
/// \return The reached arc \c a with <tt>am[a]</tt> true or |
1527 | 1522 |
/// \c INVALID if no such arc was found. |
1528 | 1523 |
/// |
1529 | 1524 |
/// \pre init() must be called and a root node should be added |
1530 | 1525 |
/// with addSource() before using this function. |
1531 | 1526 |
/// |
1532 | 1527 |
/// \warning Contrary to \ref Bfs and \ref Dijkstra, \c am is an arc map, |
1533 | 1528 |
/// not a node map. |
1534 | 1529 |
template <typename AM> |
1535 | 1530 |
Arc start(const AM &am) { |
1536 | 1531 |
while ( !emptyQueue() && !am[_stack[_stack_head]] ) |
1537 | 1532 |
processNextArc(); |
1538 | 1533 |
return emptyQueue() ? INVALID : _stack[_stack_head]; |
1539 | 1534 |
} |
1540 | 1535 |
|
1541 | 1536 |
/// \brief Runs the algorithm from the given source node. |
1542 | 1537 |
/// |
1543 | 1538 |
/// This method runs the %DFS algorithm from node \c s. |
1544 | 1539 |
/// in order to compute the DFS path to each node. |
1545 | 1540 |
/// |
1546 | 1541 |
/// The algorithm computes |
1547 | 1542 |
/// - the %DFS tree, |
1548 | 1543 |
/// - the distance of each node from the root in the %DFS tree. |
1549 | 1544 |
/// |
1550 | 1545 |
/// \note <tt>d.run(s)</tt> is just a shortcut of the following code. |
1551 | 1546 |
///\code |
1552 | 1547 |
/// d.init(); |
1553 | 1548 |
/// d.addSource(s); |
1554 | 1549 |
/// d.start(); |
1555 | 1550 |
///\endcode |
1556 | 1551 |
void run(Node s) { |
1557 | 1552 |
init(); |
1558 | 1553 |
addSource(s); |
1559 | 1554 |
start(); |
1560 | 1555 |
} |
1561 | 1556 |
|
1562 | 1557 |
/// \brief Finds the %DFS path between \c s and \c t. |
1563 | 1558 |
|
1564 | 1559 |
/// This method runs the %DFS algorithm from node \c s |
1565 | 1560 |
/// in order to compute the DFS path to node \c t |
1566 | 1561 |
/// (it stops searching when \c t is processed). |
1567 | 1562 |
/// |
1568 | 1563 |
/// \return \c true if \c t is reachable form \c s. |
1569 | 1564 |
/// |
1570 | 1565 |
/// \note Apart from the return value, <tt>d.run(s,t)</tt> is |
1571 | 1566 |
/// just a shortcut of the following code. |
1572 | 1567 |
///\code |
1573 | 1568 |
/// d.init(); |
1574 | 1569 |
/// d.addSource(s); |
1575 | 1570 |
/// d.start(t); |
1576 | 1571 |
///\endcode |
1577 | 1572 |
bool run(Node s,Node t) { |
1578 | 1573 |
init(); |
1579 | 1574 |
addSource(s); |
1580 | 1575 |
start(t); |
1581 | 1576 |
return reached(t); |
1582 | 1577 |
} |
1583 | 1578 |
|
1584 | 1579 |
/// \brief Runs the algorithm to visit all nodes in the digraph. |
1585 | 1580 |
|
1586 | 1581 |
/// This method runs the %DFS algorithm in order to |
1587 | 1582 |
/// compute the %DFS path to each node. |
1588 | 1583 |
/// |
1589 | 1584 |
/// The algorithm computes |
1590 | 1585 |
/// - the %DFS tree (forest), |
1591 | 1586 |
/// - the distance of each node from the root(s) in the %DFS tree. |
1592 | 1587 |
/// |
1593 | 1588 |
/// \note <tt>d.run()</tt> is just a shortcut of the following code. |
1594 | 1589 |
///\code |
1595 | 1590 |
/// d.init(); |
1596 | 1591 |
/// for (NodeIt n(digraph); n != INVALID; ++n) { |
1597 | 1592 |
/// if (!d.reached(n)) { |
1598 | 1593 |
/// d.addSource(n); |
1599 | 1594 |
/// d.start(); |
1600 | 1595 |
/// } |
1601 | 1596 |
/// } |
1602 | 1597 |
///\endcode |
1603 | 1598 |
void run() { |
1604 | 1599 |
init(); |
1605 | 1600 |
for (NodeIt it(*_digraph); it != INVALID; ++it) { |
1606 | 1601 |
if (!reached(it)) { |
1607 | 1602 |
addSource(it); |
1608 | 1603 |
start(); |
1609 | 1604 |
} |
1610 | 1605 |
} |
1611 | 1606 |
} |
1612 | 1607 |
|
1613 | 1608 |
///@} |
1614 | 1609 |
|
1615 | 1610 |
/// \name Query Functions |
1616 | 1611 |
/// The results of the DFS algorithm can be obtained using these |
1617 | 1612 |
/// functions.\n |
1618 | 1613 |
/// Either \ref run(Node) "run()" or \ref start() should be called |
1619 | 1614 |
/// before using them. |
1620 | 1615 |
|
1621 | 1616 |
///@{ |
1622 | 1617 |
|
1623 |
/// \brief Checks if |
|
1618 |
/// \brief Checks if the given node is reached from the root(s). |
|
1624 | 1619 |
/// |
1625 | 1620 |
/// Returns \c true if \c v is reached from the root(s). |
1626 | 1621 |
/// |
1627 | 1622 |
/// \pre Either \ref run(Node) "run()" or \ref init() |
1628 | 1623 |
/// must be called before using this function. |
1629 | 1624 |
bool reached(Node v) const { return (*_reached)[v]; } |
1630 | 1625 |
|
1631 | 1626 |
///@} |
1632 | 1627 |
|
1633 | 1628 |
}; |
1634 | 1629 |
|
1635 | 1630 |
} //END OF NAMESPACE LEMON |
1636 | 1631 |
|
1637 | 1632 |
#endif |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_DIJKSTRA_H |
20 | 20 |
#define LEMON_DIJKSTRA_H |
21 | 21 |
|
22 | 22 |
///\ingroup shortest_path |
23 | 23 |
///\file |
24 | 24 |
///\brief Dijkstra algorithm. |
25 | 25 |
|
26 | 26 |
#include <limits> |
27 | 27 |
#include <lemon/list_graph.h> |
28 | 28 |
#include <lemon/bin_heap.h> |
29 | 29 |
#include <lemon/bits/path_dump.h> |
30 | 30 |
#include <lemon/core.h> |
31 | 31 |
#include <lemon/error.h> |
32 | 32 |
#include <lemon/maps.h> |
33 | 33 |
#include <lemon/path.h> |
34 | 34 |
|
35 | 35 |
namespace lemon { |
36 | 36 |
|
37 | 37 |
/// \brief Default operation traits for the Dijkstra algorithm class. |
38 | 38 |
/// |
39 | 39 |
/// This operation traits class defines all computational operations and |
40 | 40 |
/// constants which are used in the Dijkstra algorithm. |
41 | 41 |
template <typename V> |
42 | 42 |
struct DijkstraDefaultOperationTraits { |
43 | 43 |
/// \e |
44 | 44 |
typedef V Value; |
45 | 45 |
/// \brief Gives back the zero value of the type. |
46 | 46 |
static Value zero() { |
47 | 47 |
return static_cast<Value>(0); |
48 | 48 |
} |
49 | 49 |
/// \brief Gives back the sum of the given two elements. |
50 | 50 |
static Value plus(const Value& left, const Value& right) { |
51 | 51 |
return left + right; |
52 | 52 |
} |
53 | 53 |
/// \brief Gives back true only if the first value is less than the second. |
54 | 54 |
static bool less(const Value& left, const Value& right) { |
55 | 55 |
return left < right; |
56 | 56 |
} |
57 | 57 |
}; |
58 | 58 |
|
59 | 59 |
///Default traits class of Dijkstra class. |
60 | 60 |
|
61 | 61 |
///Default traits class of Dijkstra class. |
62 | 62 |
///\tparam GR The type of the digraph. |
63 | 63 |
///\tparam LEN The type of the length map. |
64 | 64 |
template<typename GR, typename LEN> |
65 | 65 |
struct DijkstraDefaultTraits |
66 | 66 |
{ |
67 | 67 |
///The type of the digraph the algorithm runs on. |
68 | 68 |
typedef GR Digraph; |
69 | 69 |
|
70 | 70 |
///The type of the map that stores the arc lengths. |
71 | 71 |
|
72 | 72 |
///The type of the map that stores the arc lengths. |
73 |
///It must |
|
73 |
///It must conform to the \ref concepts::ReadMap "ReadMap" concept. |
|
74 | 74 |
typedef LEN LengthMap; |
75 |
///The type of the |
|
75 |
///The type of the arc lengths. |
|
76 | 76 |
typedef typename LEN::Value Value; |
77 | 77 |
|
78 | 78 |
/// Operation traits for %Dijkstra algorithm. |
79 | 79 |
|
80 | 80 |
/// This class defines the operations that are used in the algorithm. |
81 | 81 |
/// \see DijkstraDefaultOperationTraits |
82 | 82 |
typedef DijkstraDefaultOperationTraits<Value> OperationTraits; |
83 | 83 |
|
84 | 84 |
/// The cross reference type used by the heap. |
85 | 85 |
|
86 | 86 |
/// The cross reference type used by the heap. |
87 | 87 |
/// Usually it is \c Digraph::NodeMap<int>. |
88 | 88 |
typedef typename Digraph::template NodeMap<int> HeapCrossRef; |
89 | 89 |
///Instantiates a \c HeapCrossRef. |
90 | 90 |
|
91 | 91 |
///This function instantiates a \ref HeapCrossRef. |
92 | 92 |
/// \param g is the digraph, to which we would like to define the |
93 | 93 |
/// \ref HeapCrossRef. |
94 | 94 |
static HeapCrossRef *createHeapCrossRef(const Digraph &g) |
95 | 95 |
{ |
96 | 96 |
return new HeapCrossRef(g); |
97 | 97 |
} |
98 | 98 |
|
99 | 99 |
///The heap type used by the %Dijkstra algorithm. |
100 | 100 |
|
101 | 101 |
///The heap type used by the Dijkstra algorithm. |
102 | 102 |
/// |
103 | 103 |
///\sa BinHeap |
104 | 104 |
///\sa Dijkstra |
105 | 105 |
typedef BinHeap<typename LEN::Value, HeapCrossRef, std::less<Value> > Heap; |
106 | 106 |
///Instantiates a \c Heap. |
107 | 107 |
|
108 | 108 |
///This function instantiates a \ref Heap. |
109 | 109 |
static Heap *createHeap(HeapCrossRef& r) |
110 | 110 |
{ |
111 | 111 |
return new Heap(r); |
112 | 112 |
} |
113 | 113 |
|
114 | 114 |
///\brief The type of the map that stores the predecessor |
115 | 115 |
///arcs of the shortest paths. |
116 | 116 |
/// |
117 | 117 |
///The type of the map that stores the predecessor |
118 | 118 |
///arcs of the shortest paths. |
119 |
///It must |
|
119 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
120 | 120 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
121 | 121 |
///Instantiates a \c PredMap. |
122 | 122 |
|
123 | 123 |
///This function instantiates a \ref PredMap. |
124 | 124 |
///\param g is the digraph, to which we would like to define the |
125 | 125 |
///\ref PredMap. |
126 | 126 |
static PredMap *createPredMap(const Digraph &g) |
127 | 127 |
{ |
128 | 128 |
return new PredMap(g); |
129 | 129 |
} |
130 | 130 |
|
131 | 131 |
///The type of the map that indicates which nodes are processed. |
132 | 132 |
|
133 | 133 |
///The type of the map that indicates which nodes are processed. |
134 |
///It must |
|
134 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
135 | 135 |
///By default it is a NullMap. |
136 | 136 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
137 | 137 |
///Instantiates a \c ProcessedMap. |
138 | 138 |
|
139 | 139 |
///This function instantiates a \ref ProcessedMap. |
140 | 140 |
///\param g is the digraph, to which |
141 | 141 |
///we would like to define the \ref ProcessedMap. |
142 | 142 |
#ifdef DOXYGEN |
143 | 143 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
144 | 144 |
#else |
145 | 145 |
static ProcessedMap *createProcessedMap(const Digraph &) |
146 | 146 |
#endif |
147 | 147 |
{ |
148 | 148 |
return new ProcessedMap(); |
149 | 149 |
} |
150 | 150 |
|
151 | 151 |
///The type of the map that stores the distances of the nodes. |
152 | 152 |
|
153 | 153 |
///The type of the map that stores the distances of the nodes. |
154 |
///It must |
|
154 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
155 | 155 |
typedef typename Digraph::template NodeMap<typename LEN::Value> DistMap; |
156 | 156 |
///Instantiates a \c DistMap. |
157 | 157 |
|
158 | 158 |
///This function instantiates a \ref DistMap. |
159 | 159 |
///\param g is the digraph, to which we would like to define |
160 | 160 |
///the \ref DistMap. |
161 | 161 |
static DistMap *createDistMap(const Digraph &g) |
162 | 162 |
{ |
163 | 163 |
return new DistMap(g); |
164 | 164 |
} |
165 | 165 |
}; |
166 | 166 |
|
167 | 167 |
///%Dijkstra algorithm class. |
168 | 168 |
|
169 | 169 |
/// \ingroup shortest_path |
170 | 170 |
///This class provides an efficient implementation of the %Dijkstra algorithm. |
171 | 171 |
/// |
172 |
///The %Dijkstra algorithm solves the single-source shortest path problem |
|
173 |
///when all arc lengths are non-negative. If there are negative lengths, |
|
174 |
///the BellmanFord algorithm should be used instead. |
|
175 |
/// |
|
172 | 176 |
///The arc lengths are passed to the algorithm using a |
173 | 177 |
///\ref concepts::ReadMap "ReadMap", |
174 | 178 |
///so it is easy to change it to any kind of length. |
175 | 179 |
///The type of the length is determined by the |
176 | 180 |
///\ref concepts::ReadMap::Value "Value" of the length map. |
177 | 181 |
///It is also possible to change the underlying priority heap. |
178 | 182 |
/// |
179 | 183 |
///There is also a \ref dijkstra() "function-type interface" for the |
180 | 184 |
///%Dijkstra algorithm, which is convenient in the simplier cases and |
181 | 185 |
///it can be used easier. |
182 | 186 |
/// |
183 | 187 |
///\tparam GR The type of the digraph the algorithm runs on. |
184 | 188 |
///The default type is \ref ListDigraph. |
185 | 189 |
///\tparam LEN A \ref concepts::ReadMap "readable" arc map that specifies |
186 | 190 |
///the lengths of the arcs. |
187 | 191 |
///It is read once for each arc, so the map may involve in |
188 | 192 |
///relatively time consuming process to compute the arc lengths if |
189 | 193 |
///it is necessary. The default map type is \ref |
190 | 194 |
///concepts::Digraph::ArcMap "GR::ArcMap<int>". |
191 | 195 |
#ifdef DOXYGEN |
192 | 196 |
template <typename GR, typename LEN, typename TR> |
193 | 197 |
#else |
194 | 198 |
template <typename GR=ListDigraph, |
195 | 199 |
typename LEN=typename GR::template ArcMap<int>, |
196 | 200 |
typename TR=DijkstraDefaultTraits<GR,LEN> > |
197 | 201 |
#endif |
198 | 202 |
class Dijkstra { |
199 | 203 |
public: |
200 | 204 |
|
201 | 205 |
///The type of the digraph the algorithm runs on. |
202 | 206 |
typedef typename TR::Digraph Digraph; |
203 | 207 |
|
204 |
///The type of the |
|
208 |
///The type of the arc lengths. |
|
205 | 209 |
typedef typename TR::LengthMap::Value Value; |
206 | 210 |
///The type of the map that stores the arc lengths. |
207 | 211 |
typedef typename TR::LengthMap LengthMap; |
208 | 212 |
///\brief The type of the map that stores the predecessor arcs of the |
209 | 213 |
///shortest paths. |
210 | 214 |
typedef typename TR::PredMap PredMap; |
211 | 215 |
///The type of the map that stores the distances of the nodes. |
212 | 216 |
typedef typename TR::DistMap DistMap; |
213 | 217 |
///The type of the map that indicates which nodes are processed. |
214 | 218 |
typedef typename TR::ProcessedMap ProcessedMap; |
215 | 219 |
///The type of the paths. |
216 | 220 |
typedef PredMapPath<Digraph, PredMap> Path; |
217 | 221 |
///The cross reference type used for the current heap. |
218 | 222 |
typedef typename TR::HeapCrossRef HeapCrossRef; |
219 | 223 |
///The heap type used by the algorithm. |
220 | 224 |
typedef typename TR::Heap Heap; |
221 | 225 |
///\brief The \ref DijkstraDefaultOperationTraits "operation traits class" |
222 | 226 |
///of the algorithm. |
223 | 227 |
typedef typename TR::OperationTraits OperationTraits; |
224 | 228 |
|
225 | 229 |
///The \ref DijkstraDefaultTraits "traits class" of the algorithm. |
226 | 230 |
typedef TR Traits; |
227 | 231 |
|
228 | 232 |
private: |
229 | 233 |
|
230 | 234 |
typedef typename Digraph::Node Node; |
231 | 235 |
typedef typename Digraph::NodeIt NodeIt; |
232 | 236 |
typedef typename Digraph::Arc Arc; |
233 | 237 |
typedef typename Digraph::OutArcIt OutArcIt; |
234 | 238 |
|
235 | 239 |
//Pointer to the underlying digraph. |
236 | 240 |
const Digraph *G; |
237 | 241 |
//Pointer to the length map. |
238 | 242 |
const LengthMap *_length; |
239 | 243 |
//Pointer to the map of predecessors arcs. |
240 | 244 |
PredMap *_pred; |
241 | 245 |
//Indicates if _pred is locally allocated (true) or not. |
242 | 246 |
bool local_pred; |
243 | 247 |
//Pointer to the map of distances. |
244 | 248 |
DistMap *_dist; |
245 | 249 |
//Indicates if _dist is locally allocated (true) or not. |
246 | 250 |
bool local_dist; |
247 | 251 |
//Pointer to the map of processed status of the nodes. |
248 | 252 |
ProcessedMap *_processed; |
249 | 253 |
//Indicates if _processed is locally allocated (true) or not. |
250 | 254 |
bool local_processed; |
251 | 255 |
//Pointer to the heap cross references. |
252 | 256 |
HeapCrossRef *_heap_cross_ref; |
253 | 257 |
//Indicates if _heap_cross_ref is locally allocated (true) or not. |
254 | 258 |
bool local_heap_cross_ref; |
255 | 259 |
//Pointer to the heap. |
256 | 260 |
Heap *_heap; |
257 | 261 |
//Indicates if _heap is locally allocated (true) or not. |
258 | 262 |
bool local_heap; |
259 | 263 |
|
260 | 264 |
//Creates the maps if necessary. |
261 | 265 |
void create_maps() |
262 | 266 |
{ |
263 | 267 |
if(!_pred) { |
264 | 268 |
local_pred = true; |
265 | 269 |
_pred = Traits::createPredMap(*G); |
266 | 270 |
} |
267 | 271 |
if(!_dist) { |
268 | 272 |
local_dist = true; |
269 | 273 |
_dist = Traits::createDistMap(*G); |
270 | 274 |
} |
271 | 275 |
if(!_processed) { |
272 | 276 |
local_processed = true; |
273 | 277 |
_processed = Traits::createProcessedMap(*G); |
274 | 278 |
} |
275 | 279 |
if (!_heap_cross_ref) { |
276 | 280 |
local_heap_cross_ref = true; |
277 | 281 |
_heap_cross_ref = Traits::createHeapCrossRef(*G); |
278 | 282 |
} |
279 | 283 |
if (!_heap) { |
280 | 284 |
local_heap = true; |
281 | 285 |
_heap = Traits::createHeap(*_heap_cross_ref); |
282 | 286 |
} |
283 | 287 |
} |
284 | 288 |
|
285 | 289 |
public: |
286 | 290 |
|
287 | 291 |
typedef Dijkstra Create; |
288 | 292 |
|
289 | 293 |
///\name Named Template Parameters |
290 | 294 |
|
291 | 295 |
///@{ |
292 | 296 |
|
293 | 297 |
template <class T> |
294 | 298 |
struct SetPredMapTraits : public Traits { |
295 | 299 |
typedef T PredMap; |
296 | 300 |
static PredMap *createPredMap(const Digraph &) |
297 | 301 |
{ |
298 | 302 |
LEMON_ASSERT(false, "PredMap is not initialized"); |
299 | 303 |
return 0; // ignore warnings |
300 | 304 |
} |
301 | 305 |
}; |
302 | 306 |
///\brief \ref named-templ-param "Named parameter" for setting |
303 | 307 |
///\c PredMap type. |
304 | 308 |
/// |
305 | 309 |
///\ref named-templ-param "Named parameter" for setting |
306 | 310 |
///\c PredMap type. |
307 |
///It must |
|
311 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
308 | 312 |
template <class T> |
309 | 313 |
struct SetPredMap |
310 | 314 |
: public Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > { |
311 | 315 |
typedef Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > Create; |
312 | 316 |
}; |
313 | 317 |
|
314 | 318 |
template <class T> |
315 | 319 |
struct SetDistMapTraits : public Traits { |
316 | 320 |
typedef T DistMap; |
317 | 321 |
static DistMap *createDistMap(const Digraph &) |
318 | 322 |
{ |
319 | 323 |
LEMON_ASSERT(false, "DistMap is not initialized"); |
320 | 324 |
return 0; // ignore warnings |
321 | 325 |
} |
322 | 326 |
}; |
323 | 327 |
///\brief \ref named-templ-param "Named parameter" for setting |
324 | 328 |
///\c DistMap type. |
325 | 329 |
/// |
326 | 330 |
///\ref named-templ-param "Named parameter" for setting |
327 | 331 |
///\c DistMap type. |
328 |
///It must |
|
332 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
329 | 333 |
template <class T> |
330 | 334 |
struct SetDistMap |
331 | 335 |
: public Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > { |
332 | 336 |
typedef Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > Create; |
333 | 337 |
}; |
334 | 338 |
|
335 | 339 |
template <class T> |
336 | 340 |
struct SetProcessedMapTraits : public Traits { |
337 | 341 |
typedef T ProcessedMap; |
338 | 342 |
static ProcessedMap *createProcessedMap(const Digraph &) |
339 | 343 |
{ |
340 | 344 |
LEMON_ASSERT(false, "ProcessedMap is not initialized"); |
341 | 345 |
return 0; // ignore warnings |
342 | 346 |
} |
343 | 347 |
}; |
344 | 348 |
///\brief \ref named-templ-param "Named parameter" for setting |
345 | 349 |
///\c ProcessedMap type. |
346 | 350 |
/// |
347 | 351 |
///\ref named-templ-param "Named parameter" for setting |
348 | 352 |
///\c ProcessedMap type. |
349 |
///It must |
|
353 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
350 | 354 |
template <class T> |
351 | 355 |
struct SetProcessedMap |
352 | 356 |
: public Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > { |
353 | 357 |
typedef Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > Create; |
354 | 358 |
}; |
355 | 359 |
|
356 | 360 |
struct SetStandardProcessedMapTraits : public Traits { |
357 | 361 |
typedef typename Digraph::template NodeMap<bool> ProcessedMap; |
358 | 362 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
359 | 363 |
{ |
360 | 364 |
return new ProcessedMap(g); |
361 | 365 |
} |
362 | 366 |
}; |
363 | 367 |
///\brief \ref named-templ-param "Named parameter" for setting |
364 | 368 |
///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
365 | 369 |
/// |
366 | 370 |
///\ref named-templ-param "Named parameter" for setting |
367 | 371 |
///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
368 | 372 |
///If you don't set it explicitly, it will be automatically allocated. |
369 | 373 |
struct SetStandardProcessedMap |
370 | 374 |
: public Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits > { |
371 | 375 |
typedef Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits > |
372 | 376 |
Create; |
373 | 377 |
}; |
374 | 378 |
|
375 | 379 |
template <class H, class CR> |
376 | 380 |
struct SetHeapTraits : public Traits { |
377 | 381 |
typedef CR HeapCrossRef; |
378 | 382 |
typedef H Heap; |
379 | 383 |
static HeapCrossRef *createHeapCrossRef(const Digraph &) { |
380 | 384 |
LEMON_ASSERT(false, "HeapCrossRef is not initialized"); |
381 | 385 |
return 0; // ignore warnings |
382 | 386 |
} |
383 | 387 |
static Heap *createHeap(HeapCrossRef &) |
384 | 388 |
{ |
385 | 389 |
LEMON_ASSERT(false, "Heap is not initialized"); |
386 | 390 |
return 0; // ignore warnings |
387 | 391 |
} |
388 | 392 |
}; |
389 | 393 |
///\brief \ref named-templ-param "Named parameter" for setting |
390 | 394 |
///heap and cross reference types |
391 | 395 |
/// |
392 | 396 |
///\ref named-templ-param "Named parameter" for setting heap and cross |
393 | 397 |
///reference types. If this named parameter is used, then external |
394 | 398 |
///heap and cross reference objects must be passed to the algorithm |
395 | 399 |
///using the \ref heap() function before calling \ref run(Node) "run()" |
396 | 400 |
///or \ref init(). |
397 | 401 |
///\sa SetStandardHeap |
398 | 402 |
template <class H, class CR = typename Digraph::template NodeMap<int> > |
399 | 403 |
struct SetHeap |
400 | 404 |
: public Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > { |
401 | 405 |
typedef Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > Create; |
402 | 406 |
}; |
403 | 407 |
|
404 | 408 |
template <class H, class CR> |
405 | 409 |
struct SetStandardHeapTraits : public Traits { |
406 | 410 |
typedef CR HeapCrossRef; |
407 | 411 |
typedef H Heap; |
408 | 412 |
static HeapCrossRef *createHeapCrossRef(const Digraph &G) { |
409 | 413 |
return new HeapCrossRef(G); |
410 | 414 |
} |
411 | 415 |
static Heap *createHeap(HeapCrossRef &R) |
412 | 416 |
{ |
413 | 417 |
return new Heap(R); |
414 | 418 |
} |
415 | 419 |
}; |
416 | 420 |
///\brief \ref named-templ-param "Named parameter" for setting |
417 | 421 |
///heap and cross reference types with automatic allocation |
418 | 422 |
/// |
419 | 423 |
///\ref named-templ-param "Named parameter" for setting heap and cross |
420 | 424 |
///reference types with automatic allocation. |
421 | 425 |
///They should have standard constructor interfaces to be able to |
422 | 426 |
///automatically created by the algorithm (i.e. the digraph should be |
423 | 427 |
///passed to the constructor of the cross reference and the cross |
424 | 428 |
///reference should be passed to the constructor of the heap). |
425 | 429 |
///However external heap and cross reference objects could also be |
426 | 430 |
///passed to the algorithm using the \ref heap() function before |
427 | 431 |
///calling \ref run(Node) "run()" or \ref init(). |
428 | 432 |
///\sa SetHeap |
429 | 433 |
template <class H, class CR = typename Digraph::template NodeMap<int> > |
430 | 434 |
struct SetStandardHeap |
431 | 435 |
: public Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> > { |
432 | 436 |
typedef Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> > |
433 | 437 |
Create; |
434 | 438 |
}; |
435 | 439 |
|
436 | 440 |
template <class T> |
437 | 441 |
struct SetOperationTraitsTraits : public Traits { |
438 | 442 |
typedef T OperationTraits; |
439 | 443 |
}; |
440 | 444 |
|
441 | 445 |
/// \brief \ref named-templ-param "Named parameter" for setting |
442 | 446 |
///\c OperationTraits type |
443 | 447 |
/// |
444 | 448 |
///\ref named-templ-param "Named parameter" for setting |
445 | 449 |
///\c OperationTraits type. |
450 |
/// For more information see \ref DijkstraDefaultOperationTraits. |
|
446 | 451 |
template <class T> |
447 | 452 |
struct SetOperationTraits |
448 | 453 |
: public Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> > { |
449 | 454 |
typedef Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> > |
450 | 455 |
Create; |
451 | 456 |
}; |
452 | 457 |
|
453 | 458 |
///@} |
454 | 459 |
|
455 | 460 |
protected: |
456 | 461 |
|
457 | 462 |
Dijkstra() {} |
458 | 463 |
|
459 | 464 |
public: |
460 | 465 |
|
461 | 466 |
///Constructor. |
462 | 467 |
|
463 | 468 |
///Constructor. |
464 | 469 |
///\param g The digraph the algorithm runs on. |
465 | 470 |
///\param length The length map used by the algorithm. |
466 | 471 |
Dijkstra(const Digraph& g, const LengthMap& length) : |
467 | 472 |
G(&g), _length(&length), |
468 | 473 |
_pred(NULL), local_pred(false), |
469 | 474 |
_dist(NULL), local_dist(false), |
470 | 475 |
_processed(NULL), local_processed(false), |
471 | 476 |
_heap_cross_ref(NULL), local_heap_cross_ref(false), |
472 | 477 |
_heap(NULL), local_heap(false) |
473 | 478 |
{ } |
474 | 479 |
|
475 | 480 |
///Destructor. |
476 | 481 |
~Dijkstra() |
477 | 482 |
{ |
478 | 483 |
if(local_pred) delete _pred; |
479 | 484 |
if(local_dist) delete _dist; |
480 | 485 |
if(local_processed) delete _processed; |
481 | 486 |
if(local_heap_cross_ref) delete _heap_cross_ref; |
482 | 487 |
if(local_heap) delete _heap; |
483 | 488 |
} |
484 | 489 |
|
485 | 490 |
///Sets the length map. |
486 | 491 |
|
487 | 492 |
///Sets the length map. |
488 | 493 |
///\return <tt> (*this) </tt> |
489 | 494 |
Dijkstra &lengthMap(const LengthMap &m) |
490 | 495 |
{ |
491 | 496 |
_length = &m; |
492 | 497 |
return *this; |
493 | 498 |
} |
494 | 499 |
|
495 | 500 |
///Sets the map that stores the predecessor arcs. |
496 | 501 |
|
497 | 502 |
///Sets the map that stores the predecessor arcs. |
498 | 503 |
///If you don't use this function before calling \ref run(Node) "run()" |
499 | 504 |
///or \ref init(), an instance will be allocated automatically. |
500 | 505 |
///The destructor deallocates this automatically allocated map, |
501 | 506 |
///of course. |
502 | 507 |
///\return <tt> (*this) </tt> |
503 | 508 |
Dijkstra &predMap(PredMap &m) |
504 | 509 |
{ |
505 | 510 |
if(local_pred) { |
506 | 511 |
delete _pred; |
507 | 512 |
local_pred=false; |
508 | 513 |
} |
509 | 514 |
_pred = &m; |
510 | 515 |
return *this; |
511 | 516 |
} |
512 | 517 |
|
513 | 518 |
///Sets the map that indicates which nodes are processed. |
514 | 519 |
|
515 | 520 |
///Sets the map that indicates which nodes are processed. |
516 | 521 |
///If you don't use this function before calling \ref run(Node) "run()" |
517 | 522 |
///or \ref init(), an instance will be allocated automatically. |
518 | 523 |
///The destructor deallocates this automatically allocated map, |
519 | 524 |
///of course. |
520 | 525 |
///\return <tt> (*this) </tt> |
521 | 526 |
Dijkstra &processedMap(ProcessedMap &m) |
522 | 527 |
{ |
523 | 528 |
if(local_processed) { |
524 | 529 |
delete _processed; |
525 | 530 |
local_processed=false; |
526 | 531 |
} |
527 | 532 |
_processed = &m; |
528 | 533 |
return *this; |
529 | 534 |
} |
530 | 535 |
|
531 | 536 |
///Sets the map that stores the distances of the nodes. |
532 | 537 |
|
533 | 538 |
///Sets the map that stores the distances of the nodes calculated by the |
534 | 539 |
///algorithm. |
535 | 540 |
///If you don't use this function before calling \ref run(Node) "run()" |
536 | 541 |
///or \ref init(), an instance will be allocated automatically. |
537 | 542 |
///The destructor deallocates this automatically allocated map, |
538 | 543 |
///of course. |
539 | 544 |
///\return <tt> (*this) </tt> |
540 | 545 |
Dijkstra &distMap(DistMap &m) |
541 | 546 |
{ |
542 | 547 |
if(local_dist) { |
543 | 548 |
delete _dist; |
544 | 549 |
local_dist=false; |
545 | 550 |
} |
546 | 551 |
_dist = &m; |
547 | 552 |
return *this; |
548 | 553 |
} |
549 | 554 |
|
550 | 555 |
///Sets the heap and the cross reference used by algorithm. |
551 | 556 |
|
552 | 557 |
///Sets the heap and the cross reference used by algorithm. |
553 | 558 |
///If you don't use this function before calling \ref run(Node) "run()" |
554 | 559 |
///or \ref init(), heap and cross reference instances will be |
555 | 560 |
///allocated automatically. |
556 | 561 |
///The destructor deallocates these automatically allocated objects, |
557 | 562 |
///of course. |
558 | 563 |
///\return <tt> (*this) </tt> |
559 | 564 |
Dijkstra &heap(Heap& hp, HeapCrossRef &cr) |
560 | 565 |
{ |
561 | 566 |
if(local_heap_cross_ref) { |
562 | 567 |
delete _heap_cross_ref; |
563 | 568 |
local_heap_cross_ref=false; |
564 | 569 |
} |
565 | 570 |
_heap_cross_ref = &cr; |
566 | 571 |
if(local_heap) { |
567 | 572 |
delete _heap; |
568 | 573 |
local_heap=false; |
569 | 574 |
} |
570 | 575 |
_heap = &hp; |
571 | 576 |
return *this; |
572 | 577 |
} |
573 | 578 |
|
574 | 579 |
private: |
575 | 580 |
|
576 | 581 |
void finalizeNodeData(Node v,Value dst) |
577 | 582 |
{ |
578 | 583 |
_processed->set(v,true); |
579 | 584 |
_dist->set(v, dst); |
580 | 585 |
} |
581 | 586 |
|
582 | 587 |
public: |
583 | 588 |
|
584 | 589 |
///\name Execution Control |
585 | 590 |
///The simplest way to execute the %Dijkstra algorithm is to use |
586 | 591 |
///one of the member functions called \ref run(Node) "run()".\n |
587 |
///If you need more control on the execution, first you have to call |
|
588 |
///\ref init(), then you can add several source nodes with |
|
592 |
///If you need better control on the execution, you have to call |
|
593 |
///\ref init() first, then you can add several source nodes with |
|
589 | 594 |
///\ref addSource(). Finally the actual path computation can be |
590 | 595 |
///performed with one of the \ref start() functions. |
591 | 596 |
|
592 | 597 |
///@{ |
593 | 598 |
|
594 | 599 |
///\brief Initializes the internal data structures. |
595 | 600 |
/// |
596 | 601 |
///Initializes the internal data structures. |
597 | 602 |
void init() |
598 | 603 |
{ |
599 | 604 |
create_maps(); |
600 | 605 |
_heap->clear(); |
601 | 606 |
for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
602 | 607 |
_pred->set(u,INVALID); |
603 | 608 |
_processed->set(u,false); |
604 | 609 |
_heap_cross_ref->set(u,Heap::PRE_HEAP); |
605 | 610 |
} |
606 | 611 |
} |
607 | 612 |
|
608 | 613 |
///Adds a new source node. |
609 | 614 |
|
610 | 615 |
///Adds a new source node to the priority heap. |
611 | 616 |
///The optional second parameter is the initial distance of the node. |
612 | 617 |
/// |
613 | 618 |
///The function checks if the node has already been added to the heap and |
614 | 619 |
///it is pushed to the heap only if either it was not in the heap |
615 | 620 |
///or the shortest path found till then is shorter than \c dst. |
616 | 621 |
void addSource(Node s,Value dst=OperationTraits::zero()) |
617 | 622 |
{ |
618 | 623 |
if(_heap->state(s) != Heap::IN_HEAP) { |
619 | 624 |
_heap->push(s,dst); |
620 | 625 |
} else if(OperationTraits::less((*_heap)[s], dst)) { |
621 | 626 |
_heap->set(s,dst); |
622 | 627 |
_pred->set(s,INVALID); |
623 | 628 |
} |
624 | 629 |
} |
625 | 630 |
|
626 | 631 |
///Processes the next node in the priority heap |
627 | 632 |
|
628 | 633 |
///Processes the next node in the priority heap. |
629 | 634 |
/// |
630 | 635 |
///\return The processed node. |
631 | 636 |
/// |
632 | 637 |
///\warning The priority heap must not be empty. |
633 | 638 |
Node processNextNode() |
634 | 639 |
{ |
635 | 640 |
Node v=_heap->top(); |
636 | 641 |
Value oldvalue=_heap->prio(); |
637 | 642 |
_heap->pop(); |
638 | 643 |
finalizeNodeData(v,oldvalue); |
639 | 644 |
|
640 | 645 |
for(OutArcIt e(*G,v); e!=INVALID; ++e) { |
641 | 646 |
Node w=G->target(e); |
642 | 647 |
switch(_heap->state(w)) { |
643 | 648 |
case Heap::PRE_HEAP: |
644 | 649 |
_heap->push(w,OperationTraits::plus(oldvalue, (*_length)[e])); |
645 | 650 |
_pred->set(w,e); |
646 | 651 |
break; |
647 | 652 |
case Heap::IN_HEAP: |
648 | 653 |
{ |
649 | 654 |
Value newvalue = OperationTraits::plus(oldvalue, (*_length)[e]); |
650 | 655 |
if ( OperationTraits::less(newvalue, (*_heap)[w]) ) { |
651 | 656 |
_heap->decrease(w, newvalue); |
652 | 657 |
_pred->set(w,e); |
653 | 658 |
} |
654 | 659 |
} |
655 | 660 |
break; |
656 | 661 |
case Heap::POST_HEAP: |
657 | 662 |
break; |
658 | 663 |
} |
659 | 664 |
} |
660 | 665 |
return v; |
661 | 666 |
} |
662 | 667 |
|
663 | 668 |
///The next node to be processed. |
664 | 669 |
|
665 | 670 |
///Returns the next node to be processed or \c INVALID if the |
666 | 671 |
///priority heap is empty. |
667 | 672 |
Node nextNode() const |
668 | 673 |
{ |
669 | 674 |
return !_heap->empty()?_heap->top():INVALID; |
670 | 675 |
} |
671 | 676 |
|
672 | 677 |
///Returns \c false if there are nodes to be processed. |
673 | 678 |
|
674 | 679 |
///Returns \c false if there are nodes to be processed |
675 | 680 |
///in the priority heap. |
676 | 681 |
bool emptyQueue() const { return _heap->empty(); } |
677 | 682 |
|
678 | 683 |
///Returns the number of the nodes to be processed. |
679 | 684 |
|
680 | 685 |
///Returns the number of the nodes to be processed |
681 | 686 |
///in the priority heap. |
682 | 687 |
int queueSize() const { return _heap->size(); } |
683 | 688 |
|
684 | 689 |
///Executes the algorithm. |
685 | 690 |
|
686 | 691 |
///Executes the algorithm. |
687 | 692 |
/// |
688 | 693 |
///This method runs the %Dijkstra algorithm from the root node(s) |
689 | 694 |
///in order to compute the shortest path to each node. |
690 | 695 |
/// |
691 | 696 |
///The algorithm computes |
692 | 697 |
///- the shortest path tree (forest), |
693 | 698 |
///- the distance of each node from the root(s). |
694 | 699 |
/// |
695 | 700 |
///\pre init() must be called and at least one root node should be |
696 | 701 |
///added with addSource() before using this function. |
697 | 702 |
/// |
698 | 703 |
///\note <tt>d.start()</tt> is just a shortcut of the following code. |
699 | 704 |
///\code |
700 | 705 |
/// while ( !d.emptyQueue() ) { |
701 | 706 |
/// d.processNextNode(); |
702 | 707 |
/// } |
703 | 708 |
///\endcode |
704 | 709 |
void start() |
705 | 710 |
{ |
706 | 711 |
while ( !emptyQueue() ) processNextNode(); |
707 | 712 |
} |
708 | 713 |
|
709 | 714 |
///Executes the algorithm until the given target node is processed. |
710 | 715 |
|
711 | 716 |
///Executes the algorithm until the given target node is processed. |
712 | 717 |
/// |
713 | 718 |
///This method runs the %Dijkstra algorithm from the root node(s) |
714 | 719 |
///in order to compute the shortest path to \c t. |
715 | 720 |
/// |
716 | 721 |
///The algorithm computes |
717 | 722 |
///- the shortest path to \c t, |
718 | 723 |
///- the distance of \c t from the root(s). |
719 | 724 |
/// |
720 | 725 |
///\pre init() must be called and at least one root node should be |
721 | 726 |
///added with addSource() before using this function. |
722 | 727 |
void start(Node t) |
723 | 728 |
{ |
724 | 729 |
while ( !_heap->empty() && _heap->top()!=t ) processNextNode(); |
725 | 730 |
if ( !_heap->empty() ) { |
726 | 731 |
finalizeNodeData(_heap->top(),_heap->prio()); |
727 | 732 |
_heap->pop(); |
728 | 733 |
} |
729 | 734 |
} |
730 | 735 |
|
731 | 736 |
///Executes the algorithm until a condition is met. |
732 | 737 |
|
733 | 738 |
///Executes the algorithm until a condition is met. |
734 | 739 |
/// |
735 | 740 |
///This method runs the %Dijkstra algorithm from the root node(s) in |
736 | 741 |
///order to compute the shortest path to a node \c v with |
737 | 742 |
/// <tt>nm[v]</tt> true, if such a node can be found. |
738 | 743 |
/// |
739 | 744 |
///\param nm A \c bool (or convertible) node map. The algorithm |
740 | 745 |
///will stop when it reaches a node \c v with <tt>nm[v]</tt> true. |
741 | 746 |
/// |
742 | 747 |
///\return The reached node \c v with <tt>nm[v]</tt> true or |
743 | 748 |
///\c INVALID if no such node was found. |
744 | 749 |
/// |
745 | 750 |
///\pre init() must be called and at least one root node should be |
746 | 751 |
///added with addSource() before using this function. |
747 | 752 |
template<class NodeBoolMap> |
748 | 753 |
Node start(const NodeBoolMap &nm) |
749 | 754 |
{ |
750 | 755 |
while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode(); |
751 | 756 |
if ( _heap->empty() ) return INVALID; |
752 | 757 |
finalizeNodeData(_heap->top(),_heap->prio()); |
753 | 758 |
return _heap->top(); |
754 | 759 |
} |
755 | 760 |
|
756 | 761 |
///Runs the algorithm from the given source node. |
757 | 762 |
|
758 | 763 |
///This method runs the %Dijkstra algorithm from node \c s |
759 | 764 |
///in order to compute the shortest path to each node. |
760 | 765 |
/// |
761 | 766 |
///The algorithm computes |
762 | 767 |
///- the shortest path tree, |
763 | 768 |
///- the distance of each node from the root. |
764 | 769 |
/// |
765 | 770 |
///\note <tt>d.run(s)</tt> is just a shortcut of the following code. |
766 | 771 |
///\code |
767 | 772 |
/// d.init(); |
768 | 773 |
/// d.addSource(s); |
769 | 774 |
/// d.start(); |
770 | 775 |
///\endcode |
771 | 776 |
void run(Node s) { |
772 | 777 |
init(); |
773 | 778 |
addSource(s); |
774 | 779 |
start(); |
775 | 780 |
} |
776 | 781 |
|
777 | 782 |
///Finds the shortest path between \c s and \c t. |
778 | 783 |
|
779 | 784 |
///This method runs the %Dijkstra algorithm from node \c s |
780 | 785 |
///in order to compute the shortest path to node \c t |
781 | 786 |
///(it stops searching when \c t is processed). |
782 | 787 |
/// |
783 | 788 |
///\return \c true if \c t is reachable form \c s. |
784 | 789 |
/// |
785 | 790 |
///\note Apart from the return value, <tt>d.run(s,t)</tt> is just a |
786 | 791 |
///shortcut of the following code. |
787 | 792 |
///\code |
788 | 793 |
/// d.init(); |
789 | 794 |
/// d.addSource(s); |
790 | 795 |
/// d.start(t); |
791 | 796 |
///\endcode |
792 | 797 |
bool run(Node s,Node t) { |
793 | 798 |
init(); |
794 | 799 |
addSource(s); |
795 | 800 |
start(t); |
796 | 801 |
return (*_heap_cross_ref)[t] == Heap::POST_HEAP; |
797 | 802 |
} |
798 | 803 |
|
799 | 804 |
///@} |
800 | 805 |
|
801 | 806 |
///\name Query Functions |
802 | 807 |
///The results of the %Dijkstra algorithm can be obtained using these |
803 | 808 |
///functions.\n |
804 |
///Either \ref run(Node) "run()" or \ref |
|
809 |
///Either \ref run(Node) "run()" or \ref init() should be called |
|
805 | 810 |
///before using them. |
806 | 811 |
|
807 | 812 |
///@{ |
808 | 813 |
|
809 |
///The shortest path to |
|
814 |
///The shortest path to the given node. |
|
810 | 815 |
|
811 |
///Returns the shortest path to |
|
816 |
///Returns the shortest path to the given node from the root(s). |
|
812 | 817 |
/// |
813 | 818 |
///\warning \c t should be reached from the root(s). |
814 | 819 |
/// |
815 | 820 |
///\pre Either \ref run(Node) "run()" or \ref init() |
816 | 821 |
///must be called before using this function. |
817 | 822 |
Path path(Node t) const { return Path(*G, *_pred, t); } |
818 | 823 |
|
819 |
///The distance of |
|
824 |
///The distance of the given node from the root(s). |
|
820 | 825 |
|
821 |
///Returns the distance of |
|
826 |
///Returns the distance of the given node from the root(s). |
|
822 | 827 |
/// |
823 | 828 |
///\warning If node \c v is not reached from the root(s), then |
824 | 829 |
///the return value of this function is undefined. |
825 | 830 |
/// |
826 | 831 |
///\pre Either \ref run(Node) "run()" or \ref init() |
827 | 832 |
///must be called before using this function. |
828 | 833 |
Value dist(Node v) const { return (*_dist)[v]; } |
829 | 834 |
|
830 |
///Returns the 'previous arc' of the shortest path tree for a node. |
|
831 |
|
|
835 |
///\brief Returns the 'previous arc' of the shortest path tree for |
|
836 |
///the given node. |
|
837 |
/// |
|
832 | 838 |
///This function returns the 'previous arc' of the shortest path |
833 | 839 |
///tree for the node \c v, i.e. it returns the last arc of a |
834 | 840 |
///shortest path from a root to \c v. It is \c INVALID if \c v |
835 | 841 |
///is not reached from the root(s) or if \c v is a root. |
836 | 842 |
/// |
837 | 843 |
///The shortest path tree used here is equal to the shortest path |
838 |
///tree used in \ref predNode(). |
|
844 |
///tree used in \ref predNode() and \ref predMap(). |
|
839 | 845 |
/// |
840 | 846 |
///\pre Either \ref run(Node) "run()" or \ref init() |
841 | 847 |
///must be called before using this function. |
842 | 848 |
Arc predArc(Node v) const { return (*_pred)[v]; } |
843 | 849 |
|
844 |
///Returns the 'previous node' of the shortest path tree for a node. |
|
845 |
|
|
850 |
///\brief Returns the 'previous node' of the shortest path tree for |
|
851 |
///the given node. |
|
852 |
/// |
|
846 | 853 |
///This function returns the 'previous node' of the shortest path |
847 | 854 |
///tree for the node \c v, i.e. it returns the last but one node |
848 |
/// |
|
855 |
///of a shortest path from a root to \c v. It is \c INVALID |
|
849 | 856 |
///if \c v is not reached from the root(s) or if \c v is a root. |
850 | 857 |
/// |
851 | 858 |
///The shortest path tree used here is equal to the shortest path |
852 |
///tree used in \ref predArc(). |
|
859 |
///tree used in \ref predArc() and \ref predMap(). |
|
853 | 860 |
/// |
854 | 861 |
///\pre Either \ref run(Node) "run()" or \ref init() |
855 | 862 |
///must be called before using this function. |
856 | 863 |
Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
857 | 864 |
G->source((*_pred)[v]); } |
858 | 865 |
|
859 | 866 |
///\brief Returns a const reference to the node map that stores the |
860 | 867 |
///distances of the nodes. |
861 | 868 |
/// |
862 | 869 |
///Returns a const reference to the node map that stores the distances |
863 | 870 |
///of the nodes calculated by the algorithm. |
864 | 871 |
/// |
865 | 872 |
///\pre Either \ref run(Node) "run()" or \ref init() |
866 | 873 |
///must be called before using this function. |
867 | 874 |
const DistMap &distMap() const { return *_dist;} |
868 | 875 |
|
869 | 876 |
///\brief Returns a const reference to the node map that stores the |
870 | 877 |
///predecessor arcs. |
871 | 878 |
/// |
872 | 879 |
///Returns a const reference to the node map that stores the predecessor |
873 |
///arcs, which form the shortest path tree. |
|
880 |
///arcs, which form the shortest path tree (forest). |
|
874 | 881 |
/// |
875 | 882 |
///\pre Either \ref run(Node) "run()" or \ref init() |
876 | 883 |
///must be called before using this function. |
877 | 884 |
const PredMap &predMap() const { return *_pred;} |
878 | 885 |
|
879 |
///Checks if |
|
886 |
///Checks if the given node is reached from the root(s). |
|
880 | 887 |
|
881 | 888 |
///Returns \c true if \c v is reached from the root(s). |
882 | 889 |
/// |
883 | 890 |
///\pre Either \ref run(Node) "run()" or \ref init() |
884 | 891 |
///must be called before using this function. |
885 | 892 |
bool reached(Node v) const { return (*_heap_cross_ref)[v] != |
886 | 893 |
Heap::PRE_HEAP; } |
887 | 894 |
|
888 | 895 |
///Checks if a node is processed. |
889 | 896 |
|
890 | 897 |
///Returns \c true if \c v is processed, i.e. the shortest |
891 | 898 |
///path to \c v has already found. |
892 | 899 |
/// |
893 | 900 |
///\pre Either \ref run(Node) "run()" or \ref init() |
894 | 901 |
///must be called before using this function. |
895 | 902 |
bool processed(Node v) const { return (*_heap_cross_ref)[v] == |
896 | 903 |
Heap::POST_HEAP; } |
897 | 904 |
|
898 |
///The current distance of |
|
905 |
///The current distance of the given node from the root(s). |
|
899 | 906 |
|
900 |
///Returns the current distance of |
|
907 |
///Returns the current distance of the given node from the root(s). |
|
901 | 908 |
///It may be decreased in the following processes. |
902 | 909 |
/// |
903 | 910 |
///\pre Either \ref run(Node) "run()" or \ref init() |
904 | 911 |
///must be called before using this function and |
905 | 912 |
///node \c v must be reached but not necessarily processed. |
906 | 913 |
Value currentDist(Node v) const { |
907 | 914 |
return processed(v) ? (*_dist)[v] : (*_heap)[v]; |
908 | 915 |
} |
909 | 916 |
|
910 | 917 |
///@} |
911 | 918 |
}; |
912 | 919 |
|
913 | 920 |
|
914 | 921 |
///Default traits class of dijkstra() function. |
915 | 922 |
|
916 | 923 |
///Default traits class of dijkstra() function. |
917 | 924 |
///\tparam GR The type of the digraph. |
918 | 925 |
///\tparam LEN The type of the length map. |
919 | 926 |
template<class GR, class LEN> |
920 | 927 |
struct DijkstraWizardDefaultTraits |
921 | 928 |
{ |
922 | 929 |
///The type of the digraph the algorithm runs on. |
923 | 930 |
typedef GR Digraph; |
924 | 931 |
///The type of the map that stores the arc lengths. |
925 | 932 |
|
926 | 933 |
///The type of the map that stores the arc lengths. |
927 |
///It must |
|
934 |
///It must conform to the \ref concepts::ReadMap "ReadMap" concept. |
|
928 | 935 |
typedef LEN LengthMap; |
929 |
///The type of the |
|
936 |
///The type of the arc lengths. |
|
930 | 937 |
typedef typename LEN::Value Value; |
931 | 938 |
|
932 | 939 |
/// Operation traits for Dijkstra algorithm. |
933 | 940 |
|
934 | 941 |
/// This class defines the operations that are used in the algorithm. |
935 | 942 |
/// \see DijkstraDefaultOperationTraits |
936 | 943 |
typedef DijkstraDefaultOperationTraits<Value> OperationTraits; |
937 | 944 |
|
938 | 945 |
/// The cross reference type used by the heap. |
939 | 946 |
|
940 | 947 |
/// The cross reference type used by the heap. |
941 | 948 |
/// Usually it is \c Digraph::NodeMap<int>. |
942 | 949 |
typedef typename Digraph::template NodeMap<int> HeapCrossRef; |
943 | 950 |
///Instantiates a \ref HeapCrossRef. |
944 | 951 |
|
945 | 952 |
///This function instantiates a \ref HeapCrossRef. |
946 | 953 |
/// \param g is the digraph, to which we would like to define the |
947 | 954 |
/// HeapCrossRef. |
948 | 955 |
static HeapCrossRef *createHeapCrossRef(const Digraph &g) |
949 | 956 |
{ |
950 | 957 |
return new HeapCrossRef(g); |
951 | 958 |
} |
952 | 959 |
|
953 | 960 |
///The heap type used by the Dijkstra algorithm. |
954 | 961 |
|
955 | 962 |
///The heap type used by the Dijkstra algorithm. |
956 | 963 |
/// |
957 | 964 |
///\sa BinHeap |
958 | 965 |
///\sa Dijkstra |
959 | 966 |
typedef BinHeap<Value, typename Digraph::template NodeMap<int>, |
960 | 967 |
std::less<Value> > Heap; |
961 | 968 |
|
962 | 969 |
///Instantiates a \ref Heap. |
963 | 970 |
|
964 | 971 |
///This function instantiates a \ref Heap. |
965 | 972 |
/// \param r is the HeapCrossRef which is used. |
966 | 973 |
static Heap *createHeap(HeapCrossRef& r) |
967 | 974 |
{ |
968 | 975 |
return new Heap(r); |
969 | 976 |
} |
970 | 977 |
|
971 | 978 |
///\brief The type of the map that stores the predecessor |
972 | 979 |
///arcs of the shortest paths. |
973 | 980 |
/// |
974 | 981 |
///The type of the map that stores the predecessor |
975 | 982 |
///arcs of the shortest paths. |
976 |
///It must |
|
983 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
977 | 984 |
typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
978 | 985 |
///Instantiates a PredMap. |
979 | 986 |
|
980 | 987 |
///This function instantiates a PredMap. |
981 | 988 |
///\param g is the digraph, to which we would like to define the |
982 | 989 |
///PredMap. |
983 | 990 |
static PredMap *createPredMap(const Digraph &g) |
984 | 991 |
{ |
985 | 992 |
return new PredMap(g); |
986 | 993 |
} |
987 | 994 |
|
988 | 995 |
///The type of the map that indicates which nodes are processed. |
989 | 996 |
|
990 | 997 |
///The type of the map that indicates which nodes are processed. |
991 |
///It must |
|
998 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
992 | 999 |
///By default it is a NullMap. |
993 | 1000 |
typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
994 | 1001 |
///Instantiates a ProcessedMap. |
995 | 1002 |
|
996 | 1003 |
///This function instantiates a ProcessedMap. |
997 | 1004 |
///\param g is the digraph, to which |
998 | 1005 |
///we would like to define the ProcessedMap. |
999 | 1006 |
#ifdef DOXYGEN |
1000 | 1007 |
static ProcessedMap *createProcessedMap(const Digraph &g) |
1001 | 1008 |
#else |
1002 | 1009 |
static ProcessedMap *createProcessedMap(const Digraph &) |
1003 | 1010 |
#endif |
1004 | 1011 |
{ |
1005 | 1012 |
return new ProcessedMap(); |
1006 | 1013 |
} |
1007 | 1014 |
|
1008 | 1015 |
///The type of the map that stores the distances of the nodes. |
1009 | 1016 |
|
1010 | 1017 |
///The type of the map that stores the distances of the nodes. |
1011 |
///It must |
|
1018 |
///It must conform to the \ref concepts::WriteMap "WriteMap" concept. |
|
1012 | 1019 |
typedef typename Digraph::template NodeMap<typename LEN::Value> DistMap; |
1013 | 1020 |
///Instantiates a DistMap. |
1014 | 1021 |
|
1015 | 1022 |
///This function instantiates a DistMap. |
1016 | 1023 |
///\param g is the digraph, to which we would like to define |
1017 | 1024 |
///the DistMap |
1018 | 1025 |
static DistMap *createDistMap(const Digraph &g) |
1019 | 1026 |
{ |
1020 | 1027 |
return new DistMap(g); |
1021 | 1028 |
} |
1022 | 1029 |
|
1023 | 1030 |
///The type of the shortest paths. |
1024 | 1031 |
|
1025 | 1032 |
///The type of the shortest paths. |
1026 |
///It must |
|
1033 |
///It must conform to the \ref concepts::Path "Path" concept. |
|
1027 | 1034 |
typedef lemon::Path<Digraph> Path; |
1028 | 1035 |
}; |
1029 | 1036 |
|
1030 | 1037 |
/// Default traits class used by DijkstraWizard |
1031 | 1038 |
|
1032 |
/// To make it easier to use Dijkstra algorithm |
|
1033 |
/// we have created a wizard class. |
|
1034 |
/// This \ref DijkstraWizard class needs default traits, |
|
1035 |
/// as well as the \ref Dijkstra class. |
|
1036 |
/// The \ref DijkstraWizardBase is a class to be the default traits of the |
|
1037 |
/// \ref DijkstraWizard class. |
|
1039 |
/// Default traits class used by DijkstraWizard. |
|
1040 |
/// \tparam GR The type of the digraph. |
|
1041 |
/// \tparam LEN The type of the length map. |
|
1038 | 1042 |
template<typename GR, typename LEN> |
1039 | 1043 |
class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LEN> |
1040 | 1044 |
{ |
1041 | 1045 |
typedef DijkstraWizardDefaultTraits<GR,LEN> Base; |
1042 | 1046 |
protected: |
1043 | 1047 |
//The type of the nodes in the digraph. |
1044 | 1048 |
typedef typename Base::Digraph::Node Node; |
1045 | 1049 |
|
1046 | 1050 |
//Pointer to the digraph the algorithm runs on. |
1047 | 1051 |
void *_g; |
1048 | 1052 |
//Pointer to the length map. |
1049 | 1053 |
void *_length; |
1050 | 1054 |
//Pointer to the map of processed nodes. |
1051 | 1055 |
void *_processed; |
1052 | 1056 |
//Pointer to the map of predecessors arcs. |
1053 | 1057 |
void *_pred; |
1054 | 1058 |
//Pointer to the map of distances. |
1055 | 1059 |
void *_dist; |
1056 | 1060 |
//Pointer to the shortest path to the target node. |
1057 | 1061 |
void *_path; |
1058 | 1062 |
//Pointer to the distance of the target node. |
1059 | 1063 |
void *_di; |
1060 | 1064 |
|
1061 | 1065 |
public: |
1062 | 1066 |
/// Constructor. |
1063 | 1067 |
|
1064 | 1068 |
/// This constructor does not require parameters, therefore it initiates |
1065 | 1069 |
/// all of the attributes to \c 0. |
1066 | 1070 |
DijkstraWizardBase() : _g(0), _length(0), _processed(0), _pred(0), |
1067 | 1071 |
_dist(0), _path(0), _di(0) {} |
1068 | 1072 |
|
1069 | 1073 |
/// Constructor. |
1070 | 1074 |
|
1071 | 1075 |
/// This constructor requires two parameters, |
1072 | 1076 |
/// others are initiated to \c 0. |
1073 | 1077 |
/// \param g The digraph the algorithm runs on. |
1074 | 1078 |
/// \param l The length map. |
1075 | 1079 |
DijkstraWizardBase(const GR &g,const LEN &l) : |
1076 | 1080 |
_g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
1077 | 1081 |
_length(reinterpret_cast<void*>(const_cast<LEN*>(&l))), |
1078 | 1082 |
_processed(0), _pred(0), _dist(0), _path(0), _di(0) {} |
1079 | 1083 |
|
1080 | 1084 |
}; |
1081 | 1085 |
|
1082 | 1086 |
/// Auxiliary class for the function-type interface of Dijkstra algorithm. |
1083 | 1087 |
|
1084 | 1088 |
/// This auxiliary class is created to implement the |
1085 | 1089 |
/// \ref dijkstra() "function-type interface" of \ref Dijkstra algorithm. |
1086 | 1090 |
/// It does not have own \ref run(Node) "run()" method, it uses the |
1087 | 1091 |
/// functions and features of the plain \ref Dijkstra. |
1088 | 1092 |
/// |
1089 | 1093 |
/// This class should only be used through the \ref dijkstra() function, |
1090 | 1094 |
/// which makes it easier to use the algorithm. |
1091 | 1095 |
template<class TR> |
1092 | 1096 |
class DijkstraWizard : public TR |
1093 | 1097 |
{ |
1094 | 1098 |
typedef TR Base; |
1095 | 1099 |
|
1096 |
///The type of the digraph the algorithm runs on. |
|
1097 | 1100 |
typedef typename TR::Digraph Digraph; |
1098 | 1101 |
|
1099 | 1102 |
typedef typename Digraph::Node Node; |
1100 | 1103 |
typedef typename Digraph::NodeIt NodeIt; |
1101 | 1104 |
typedef typename Digraph::Arc Arc; |
1102 | 1105 |
typedef typename Digraph::OutArcIt OutArcIt; |
1103 | 1106 |
|
1104 |
///The type of the map that stores the arc lengths. |
|
1105 | 1107 |
typedef typename TR::LengthMap LengthMap; |
1106 |
///The type of the length of the arcs. |
|
1107 | 1108 |
typedef typename LengthMap::Value Value; |
1108 |
///\brief The type of the map that stores the predecessor |
|
1109 |
///arcs of the shortest paths. |
|
1110 | 1109 |
typedef typename TR::PredMap PredMap; |
1111 |
///The type of the map that stores the distances of the nodes. |
|
1112 | 1110 |
typedef typename TR::DistMap DistMap; |
1113 |
///The type of the map that indicates which nodes are processed. |
|
1114 | 1111 |
typedef typename TR::ProcessedMap ProcessedMap; |
1115 |
///The type of the shortest paths |
|
1116 | 1112 |
typedef typename TR::Path Path; |
1117 |
///The heap type used by the dijkstra algorithm. |
|
1118 | 1113 |
typedef typename TR::Heap Heap; |
1119 | 1114 |
|
1120 | 1115 |
public: |
1121 | 1116 |
|
1122 | 1117 |
/// Constructor. |
1123 | 1118 |
DijkstraWizard() : TR() {} |
1124 | 1119 |
|
1125 | 1120 |
/// Constructor that requires parameters. |
1126 | 1121 |
|
1127 | 1122 |
/// Constructor that requires parameters. |
1128 | 1123 |
/// These parameters will be the default values for the traits class. |
1129 | 1124 |
/// \param g The digraph the algorithm runs on. |
1130 | 1125 |
/// \param l The length map. |
1131 | 1126 |
DijkstraWizard(const Digraph &g, const LengthMap &l) : |
1132 | 1127 |
TR(g,l) {} |
1133 | 1128 |
|
1134 | 1129 |
///Copy constructor |
1135 | 1130 |
DijkstraWizard(const TR &b) : TR(b) {} |
1136 | 1131 |
|
1137 | 1132 |
~DijkstraWizard() {} |
1138 | 1133 |
|
1139 | 1134 |
///Runs Dijkstra algorithm from the given source node. |
1140 | 1135 |
|
1141 | 1136 |
///This method runs %Dijkstra algorithm from the given source node |
1142 | 1137 |
///in order to compute the shortest path to each node. |
1143 | 1138 |
void run(Node s) |
1144 | 1139 |
{ |
1145 | 1140 |
Dijkstra<Digraph,LengthMap,TR> |
1146 | 1141 |
dijk(*reinterpret_cast<const Digraph*>(Base::_g), |
1147 | 1142 |
*reinterpret_cast<const LengthMap*>(Base::_length)); |
1148 | 1143 |
if (Base::_pred) |
1149 | 1144 |
dijk.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
1150 | 1145 |
if (Base::_dist) |
1151 | 1146 |
dijk.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
1152 | 1147 |
if (Base::_processed) |
1153 | 1148 |
dijk.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
1154 | 1149 |
dijk.run(s); |
1155 | 1150 |
} |
1156 | 1151 |
|
1157 | 1152 |
///Finds the shortest path between \c s and \c t. |
1158 | 1153 |
|
1159 | 1154 |
///This method runs the %Dijkstra algorithm from node \c s |
1160 | 1155 |
///in order to compute the shortest path to node \c t |
1161 | 1156 |
///(it stops searching when \c t is processed). |
1162 | 1157 |
/// |
1163 | 1158 |
///\return \c true if \c t is reachable form \c s. |
1164 | 1159 |
bool run(Node s, Node t) |
1165 | 1160 |
{ |
1166 | 1161 |
Dijkstra<Digraph,LengthMap,TR> |
1167 | 1162 |
dijk(*reinterpret_cast<const Digraph*>(Base::_g), |
1168 | 1163 |
*reinterpret_cast<const LengthMap*>(Base::_length)); |
1169 | 1164 |
if (Base::_pred) |
1170 | 1165 |
dijk.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
1171 | 1166 |
if (Base::_dist) |
1172 | 1167 |
dijk.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
1173 | 1168 |
if (Base::_processed) |
1174 | 1169 |
dijk.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
1175 | 1170 |
dijk.run(s,t); |
1176 | 1171 |
if (Base::_path) |
1177 | 1172 |
*reinterpret_cast<Path*>(Base::_path) = dijk.path(t); |
1178 | 1173 |
if (Base::_di) |
1179 | 1174 |
*reinterpret_cast<Value*>(Base::_di) = dijk.dist(t); |
1180 | 1175 |
return dijk.reached(t); |
1181 | 1176 |
} |
1182 | 1177 |
|
1183 | 1178 |
template<class T> |
1184 | 1179 |
struct SetPredMapBase : public Base { |
1185 | 1180 |
typedef T PredMap; |
1186 | 1181 |
static PredMap *createPredMap(const Digraph &) { return 0; }; |
1187 | 1182 |
SetPredMapBase(const TR &b) : TR(b) {} |
1188 | 1183 |
}; |
1189 |
///\brief \ref named-func-param "Named parameter" |
|
1190 |
///for setting PredMap object. |
|
1184 |
|
|
1185 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1186 |
///the predecessor map. |
|
1191 | 1187 |
/// |
1192 |
///\ref named-func-param "Named parameter" |
|
1193 |
///for setting PredMap object. |
|
1188 |
///\ref named-templ-param "Named parameter" function for setting |
|
1189 |
///the map that stores the predecessor arcs of the nodes. |
|
1194 | 1190 |
template<class T> |
1195 | 1191 |
DijkstraWizard<SetPredMapBase<T> > predMap(const T &t) |
1196 | 1192 |
{ |
1197 | 1193 |
Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1198 | 1194 |
return DijkstraWizard<SetPredMapBase<T> >(*this); |
1199 | 1195 |
} |
1200 | 1196 |
|
1201 | 1197 |
template<class T> |
1202 | 1198 |
struct SetDistMapBase : public Base { |
1203 | 1199 |
typedef T DistMap; |
1204 | 1200 |
static DistMap *createDistMap(const Digraph &) { return 0; }; |
1205 | 1201 |
SetDistMapBase(const TR &b) : TR(b) {} |
1206 | 1202 |
}; |
1207 |
///\brief \ref named-func-param "Named parameter" |
|
1208 |
///for setting DistMap object. |
|
1203 |
|
|
1204 |
///\brief \ref named-templ-param "Named parameter" for setting |
|
1205 |
///the distance map. |
|
1209 | 1206 |
/// |
1210 |
///\ref named-func-param "Named parameter" |
|
1211 |
///for setting DistMap object. |
|
1207 |
///\ref named-templ-param "Named parameter" function for setting |
|
1208 |
///the map that stores the distances of the nodes calculated |
|
1209 |
///by the algorithm. |
|
1212 | 1210 |
template<class T> |
1213 | 1211 |
DijkstraWizard<SetDistMapBase<T> > distMap(const T &t) |
1214 | 1212 |
{ |
1215 | 1213 |
Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1216 | 1214 |
return DijkstraWizard<SetDistMapBase<T> >(*this); |
1217 | 1215 |
} |
1218 | 1216 |
|
1219 | 1217 |
template<class T> |
1220 | 1218 |
struct SetProcessedMapBase : public Base { |
1221 | 1219 |
typedef T ProcessedMap; |
1222 | 1220 |
static ProcessedMap *createProcessedMap(const Digraph &) { return 0; }; |
1223 | 1221 |
SetProcessedMapBase(const TR &b) : TR(b) {} |
1224 | 1222 |
}; |
1225 |
///\brief \ref named-func-param "Named parameter" |
|
1226 |
///for setting ProcessedMap object. |
|
1223 |
|
|
1224 |
///\brief \ref named-func-param "Named parameter" for setting |
|
1225 |
///the processed map. |
|
1227 | 1226 |
/// |
1228 |
/// \ref named-func-param "Named parameter" |
|
1229 |
///for setting ProcessedMap object. |
|
1227 |
///\ref named-templ-param "Named parameter" function for setting |
|
1228 |
///the map that indicates which nodes are processed. |
|
1230 | 1229 |
template<class T> |
1231 | 1230 |
DijkstraWizard<SetProcessedMapBase<T> > processedMap(const T &t) |
1232 | 1231 |
{ |
1233 | 1232 |
Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1234 | 1233 |
return DijkstraWizard<SetProcessedMapBase<T> >(*this); |
1235 | 1234 |
} |
1236 | 1235 |
|
1237 | 1236 |
template<class T> |
1238 | 1237 |
struct SetPathBase : public Base { |
1239 | 1238 |
typedef T Path; |
1240 | 1239 |
SetPathBase(const TR &b) : TR(b) {} |
1241 | 1240 |
}; |
1241 |
|
|
1242 | 1242 |
///\brief \ref named-func-param "Named parameter" |
1243 | 1243 |
///for getting the shortest path to the target node. |
1244 | 1244 |
/// |
1245 | 1245 |
///\ref named-func-param "Named parameter" |
1246 | 1246 |
///for getting the shortest path to the target node. |
1247 | 1247 |
template<class T> |
1248 | 1248 |
DijkstraWizard<SetPathBase<T> > path(const T &t) |
1249 | 1249 |
{ |
1250 | 1250 |
Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t)); |
1251 | 1251 |
return DijkstraWizard<SetPathBase<T> >(*this); |
1252 | 1252 |
} |
1253 | 1253 |
|
1254 | 1254 |
///\brief \ref named-func-param "Named parameter" |
1255 | 1255 |
///for getting the distance of the target node. |
1256 | 1256 |
/// |
1257 | 1257 |
///\ref named-func-param "Named parameter" |
1258 | 1258 |
///for getting the distance of the target node. |
1259 | 1259 |
DijkstraWizard dist(const Value &d) |
1260 | 1260 |
{ |
1261 | 1261 |
Base::_di=reinterpret_cast<void*>(const_cast<Value*>(&d)); |
1262 | 1262 |
return *this; |
1263 | 1263 |
} |
1264 | 1264 |
|
1265 | 1265 |
}; |
1266 | 1266 |
|
1267 | 1267 |
///Function-type interface for Dijkstra algorithm. |
1268 | 1268 |
|
1269 | 1269 |
/// \ingroup shortest_path |
1270 | 1270 |
///Function-type interface for Dijkstra algorithm. |
1271 | 1271 |
/// |
1272 | 1272 |
///This function also has several \ref named-func-param "named parameters", |
1273 | 1273 |
///they are declared as the members of class \ref DijkstraWizard. |
1274 | 1274 |
///The following examples show how to use these parameters. |
1275 | 1275 |
///\code |
1276 | 1276 |
/// // Compute shortest path from node s to each node |
1277 | 1277 |
/// dijkstra(g,length).predMap(preds).distMap(dists).run(s); |
1278 | 1278 |
/// |
1279 | 1279 |
/// // Compute shortest path from s to t |
1280 | 1280 |
/// bool reached = dijkstra(g,length).path(p).dist(d).run(s,t); |
1281 | 1281 |
///\endcode |
1282 | 1282 |
///\warning Don't forget to put the \ref DijkstraWizard::run(Node) "run()" |
1283 | 1283 |
///to the end of the parameter list. |
1284 | 1284 |
///\sa DijkstraWizard |
1285 | 1285 |
///\sa Dijkstra |
1286 | 1286 |
template<typename GR, typename LEN> |
1287 | 1287 |
DijkstraWizard<DijkstraWizardBase<GR,LEN> > |
1288 | 1288 |
dijkstra(const GR &digraph, const LEN &length) |
1289 | 1289 |
{ |
1290 | 1290 |
return DijkstraWizard<DijkstraWizardBase<GR,LEN> >(digraph,length); |
1291 | 1291 |
} |
1292 | 1292 |
|
1293 | 1293 |
} //END OF NAMESPACE LEMON |
1294 | 1294 |
|
1295 | 1295 |
#endif |
1 | 1 |
/* -*- mode: C++; indent-tabs-mode: nil; -*- |
2 | 2 |
* |
3 | 3 |
* This file is a part of LEMON, a generic C++ optimization library. |
4 | 4 |
* |
5 | 5 |
* Copyright (C) 2003-2009 |
6 | 6 |
* Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
7 | 7 |
* (Egervary Research Group on Combinatorial Optimization, EGRES). |
8 | 8 |
* |
9 | 9 |
* Permission to use, modify and distribute this software is granted |
10 | 10 |
* provided that this copyright notice appears in all copies. For |
11 | 11 |
* precise terms see the accompanying LICENSE file. |
12 | 12 |
* |
13 | 13 |
* This software is provided "AS IS" with no warranty of any kind, |
14 | 14 |
* express or implied, and with no claim as to its suitability for any |
15 | 15 |
* purpose. |
16 | 16 |
* |
17 | 17 |
*/ |
18 | 18 |
|
19 | 19 |
#ifndef LEMON_DIM2_H |
20 | 20 |
#define LEMON_DIM2_H |
21 | 21 |
|
22 | 22 |
#include <iostream> |
23 | 23 |
|
24 |
///\ingroup |
|
24 |
///\ingroup geomdat |
|
25 | 25 |
///\file |
26 | 26 |
///\brief A simple two dimensional vector and a bounding box implementation |
27 |
/// |
|
28 |
/// The class \ref lemon::dim2::Point "dim2::Point" implements |
|
29 |
/// a two dimensional vector with the usual operations. |
|
30 |
/// |
|
31 |
/// The class \ref lemon::dim2::Box "dim2::Box" can be used to determine |
|
32 |
/// the rectangular bounding box of a set of |
|
33 |
/// \ref lemon::dim2::Point "dim2::Point"'s. |
|
34 | 27 |
|
35 | 28 |
namespace lemon { |
36 | 29 |
|
37 | 30 |
///Tools for handling two dimensional coordinates |
38 | 31 |
|
39 | 32 |
///This namespace is a storage of several |
40 | 33 |
///tools for handling two dimensional coordinates |
41 | 34 |
namespace dim2 { |
42 | 35 |
|
43 |
/// \addtogroup |
|
36 |
/// \addtogroup geomdat |
|
44 | 37 |
/// @{ |
45 | 38 |
|
46 | 39 |
/// Two dimensional vector (plain vector) |
47 | 40 |
|
48 | 41 |
/// A simple two dimensional vector (plain vector) implementation |
49 | 42 |
/// with the usual vector operations. |
50 | 43 |
template<typename T> |
51 | 44 |
class Point { |
52 | 45 |
|
53 | 46 |
public: |
54 | 47 |
|
55 | 48 |
typedef T Value; |
56 | 49 |
|
57 | 50 |
///First coordinate |
58 | 51 |
T x; |
59 | 52 |
///Second coordinate |
60 | 53 |
T y; |
61 | 54 |
|
62 | 55 |
///Default constructor |
63 | 56 |
Point() {} |
64 | 57 |
|
65 | 58 |
///Construct an instance from coordinates |
66 | 59 |
Point(T a, T b) : x(a), y(b) { } |
67 | 60 |
|
68 | 61 |
///Returns the dimension of the vector (i.e. returns 2). |
69 | 62 |
|
70 | 63 |
///The dimension of the vector. |
71 | 64 |
///This function always returns 2. |
72 | 65 |
int size() const { return 2; } |
73 | 66 |
|
74 | 67 |
///Subscripting operator |
75 | 68 |
|
76 | 69 |
///\c p[0] is \c p.x and \c p[1] is \c p.y |
77 | 70 |
/// |
78 | 71 |
T& operator[](int idx) { return idx == 0 ? x : y; } |
79 | 72 |
|
80 | 73 |
///Const subscripting operator |
81 | 74 |
|
82 | 75 |
///\c p[0] is \c p.x and \c p[1] is \c p.y |
83 | 76 |
/// |
84 | 77 |
const T& operator[](int idx) const { return idx == 0 ? x : y; } |
85 | 78 |
|
86 | 79 |
///Conversion constructor |
87 | 80 |
template<class TT> Point(const Point<TT> &p) : x(p.x), y(p.y) {} |
88 | 81 |
|
89 | 82 |
///Give back the square of the norm of the vector |
90 | 83 |
T normSquare() const { |
91 | 84 |
return x*x+y*y; |
92 | 85 |
} |
93 | 86 |
|
94 | 87 |
///Increment the left hand side by \c u |
95 | 88 |
Point<T>& operator +=(const Point<T>& u) { |
96 | 89 |
x += u.x; |
97 | 90 |
y += u.y; |
98 | 91 |
return *this; |
99 | 92 |
} |
100 | 93 |
|
101 | 94 |
///Decrement the left hand side by \c u |
102 | 95 |
Point<T>& operator -=(const Point<T>& u) { |
103 | 96 |
x -= u.x; |
104 | 97 |
y -= u.y; |
105 | 98 |
return *this; |
106 | 99 |
} |
107 | 100 |
|
108 | 101 |
///Multiply the left hand side with a scalar |
109 | 102 |
Point<T>& operator *=(const T &u) { |
110 | 103 |
x *= u; |
111 | 104 |
y *= u; |
112 | 105 |
return *this; |
113 | 106 |
} |
114 | 107 |
|
115 | 108 |
///Divide the left hand side by a scalar |
116 | 109 |
Point<T>& operator /=(const T &u) { |
117 | 110 |
x /= u; |
118 | 111 |
y /= u; |
119 | 112 |
return *this; |
120 | 113 |
} |
121 | 114 |
|
122 | 115 |
///Return the scalar product of two vectors |
123 | 116 |
T operator *(const Point<T>& u) const { |
124 | 117 |
return x*u.x+y*u.y; |
125 | 118 |
} |
126 | 119 |
|
127 | 120 |
///Return the sum of two vectors |
128 | 121 |
Point<T> operator+(const Point<T> &u) const { |
129 | 122 |
Point<T> b=*this; |
130 | 123 |
return b+=u; |
131 | 124 |
} |
132 | 125 |
|
133 | 126 |
///Return the negative of the vector |
134 | 127 |
Point<T> operator-() const { |
135 | 128 |
Point<T> b=*this; |
136 | 129 |
b.x=-b.x; b.y=-b.y; |
137 | 130 |
return b; |
138 | 131 |
} |
139 | 132 |
|
140 | 133 |
///Return the difference of two vectors |
141 | 134 |
Point<T> operator-(const Point<T> &u) const { |
142 | 135 |
Point<T> b=*this; |
143 | 136 |
return b-=u; |
144 | 137 |
} |
145 | 138 |
|
146 | 139 |
///Return a vector multiplied by a scalar |
147 | 140 |
Point<T> operator*(const T &u) const { |
148 | 141 |
Point<T> b=*this; |
149 | 142 |
return b*=u; |
150 | 143 |
} |
151 | 144 |
|
152 | 145 |
///Return a vector divided by a scalar |
153 | 146 |
Point<T> operator/(const T &u) const { |
154 | 147 |
Point<T> b=*this; |
155 | 148 |
return b/=u; |
156 | 149 |
} |
157 | 150 |
|
158 | 151 |
///Test equality |
159 | 152 |
bool operator==(const Point<T> &u) const { |
160 | 153 |
return (x==u.x) && (y==u.y); |
161 | 154 |
} |
162 | 155 |
|
163 | 156 |
///Test inequality |
164 | 157 |
bool operator!=(Point u) const { |
165 | 158 |
return (x!=u.x) || (y!=u.y); |
166 | 159 |
} |
167 | 160 |
|
168 | 161 |
}; |
169 | 162 |
|
170 | 163 |
///Return a Point |
171 | 164 |
|
172 | 165 |
///Return a Point. |
173 | 166 |
///\relates Point |
174 | 167 |
template <typename T> |
175 | 168 |
inline Point<T> makePoint(const T& x, const T& y) { |
176 | 169 |
return Point<T>(x, y); |
177 | 170 |
} |
178 | 171 |
|
179 | 172 |
///Return a vector multiplied by a scalar |
180 | 173 |
|
181 | 174 |
///Return a vector multiplied by a scalar. |
182 | 175 |
///\relates Point |
183 | 176 |
template<typename T> Point<T> operator*(const T &u,const Point<T> &x) { |
184 | 177 |
return x*u; |
185 | 178 |
} |
186 | 179 |
|
187 | 180 |
///Read a plain vector from a stream |
188 | 181 |
|
189 | 182 |
///Read a plain vector from a stream. |
190 | 183 |
///\relates Point |
191 | 184 |
/// |
192 | 185 |
template<typename T> |
193 | 186 |
inline std::istream& operator>>(std::istream &is, Point<T> &z) { |
194 | 187 |
char c; |
195 | 188 |
if (is >> c) { |
196 | 189 |
if (c != '(') is.putback(c); |
197 | 190 |
} else { |
198 | 191 |
is.clear(); |
199 | 192 |
} |
200 | 193 |
if (!(is >> z.x)) return is; |
201 | 194 |
if (is >> c) { |
202 | 195 |
if (c != ',') is.putback(c); |
203 | 196 |
} else { |
204 | 197 |
is.clear(); |
205 | 198 |
} |
206 | 199 |
if (!(is >> z.y)) return is; |
207 | 200 |
if (is >> c) { |
208 | 201 |
if (c != ')') is.putback(c); |
209 | 202 |
} else { |
210 | 203 |
is.clear(); |
211 | 204 |
} |
212 | 205 |
return is; |
213 | 206 |
} |
214 | 207 |
|
215 | 208 |
///Write a plain vector to a stream |
216 | 209 |
|
217 | 210 |
///Write a plain vector to a stream. |
218 | 211 |
///\relates Point |
219 | 212 |
/// |
220 | 213 |
template<typename T> |
221 | 214 |
inline std::ostream& operator<<(std::ostream &os, const Point<T>& z) |
222 | 215 |
{ |
223 | 216 |
os << "(" << z.x << "," << z.y << ")"; |
224 | 217 |
return os; |
225 | 218 |
} |
226 | 219 |
|
227 | 220 |
///Rotate by 90 degrees |
228 | 221 |
|
229 | 222 |
///Returns the parameter rotated by 90 degrees in positive direction. |
230 | 223 |
///\relates Point |
231 | 224 |
/// |
232 | 225 |
template<typename T> |
233 | 226 |
inline Point<T> rot90(const Point<T> &z) |
234 | 227 |
{ |
235 | 228 |
return Point<T>(-z.y,z.x); |
236 | 229 |
} |
237 | 230 |
|
238 | 231 |
///Rotate by 180 degrees |
239 | 232 |
|
240 | 233 |
///Returns the parameter rotated by 180 degrees. |
241 | 234 |
///\relates Point |
242 | 235 |
/// |
243 | 236 |
template<typename T> |
244 | 237 |
inline Point<T> rot180(const Point<T> &z) |
245 | 238 |
{ |
246 | 239 |
return Point<T>(-z.x,-z.y); |
247 | 240 |
} |
248 | 241 |
|
249 | 242 |
///Rotate by 270 degrees |
250 | 243 |
|
251 | 244 |
///Returns the parameter rotated by 90 degrees in negative direction. |
252 | 245 |
///\relates Point |
253 | 246 |
/// |
254 | 247 |
template<typename T> |
255 | 248 |
inline Point<T> rot270(const Point<T> &z) |
256 | 249 |
{ |
257 | 250 |
return Point<T>(z.y,-z.x); |
258 | 251 |
} |
259 | 252 |
|
260 | 253 |
|
261 | 254 |
|
262 | 255 |
/// Bounding box of plain vectors (points). |
263 | 256 |
|
264 | 257 |
/// A class to calculate or store the bounding box of plain vectors |
265 | 258 |
/// (\ref Point "points"). |
266 | 259 |
template<typename T> |
267 | 260 |
class Box { |
268 | 261 |
Point<T> _bottom_left, _top_right; |
269 | 262 |
bool _empty; |
270 | 263 |
public: |
271 | 264 |
|
272 | 265 |
///Default constructor: creates an empty box |
273 | 266 |
Box() { _empty = true; } |
274 | 267 |
|
275 | 268 |
///Construct a box from one point |
276 | 269 |
Box(Point<T> a) { |
277 | 270 |
_bottom_left = _top_right = a; |
278 | 271 |
_empty = false; |
279 | 272 |
} |
280 | 273 |
|
281 | 274 |
///Construct a box from two points |
282 | 275 |
|
283 | 276 |
///Construct a box from two points. |
284 | 277 |
///\param a The bottom left corner. |
285 | 278 |
///\param b The top right corner. |
286 | 279 |
///\warning The coordinates of the bottom left corner must be no more |
287 | 280 |
///than those of the top right one. |
288 | 281 |
Box(Point<T> a,Point<T> b) |
289 | 282 |
{ |
290 | 283 |
_bottom_left = a; |
291 | 284 |
_top_right = b; |
292 | 285 |
_empty = false; |
293 | 286 |
} |
294 | 287 |
|
295 | 288 |
///Construct a box from four numbers |
296 | 289 |
|
297 | 290 |
///Construct a box from four numbers. |
298 | 291 |
///\param l The left side of the box. |
299 | 292 |
///\param b The bottom of the box. |
300 | 293 |
///\param r The right side of the box. |
301 | 294 |
///\param t The top of the box. |
302 | 295 |
///\warning The left side must be no more than the right side and |
303 | 296 |
///bottom must be no more than the top. |
304 | 297 |
Box(T l,T b,T r,T t) |
305 | 298 |
{ |
306 | 299 |
_bottom_left=Point<T>(l,b); |
307 | 300 |
_top_right=Point<T>(r,t); |
308 | 301 |
_empty = false; |
309 | 302 |
} |
310 | 303 |
|
311 | 304 |
///Return \c true if the box is empty. |
312 | 305 |
|
313 | 306 |
///Return \c true if the box is empty (i.e. return \c false |
314 | 307 |
///if at least one point was added to the box or the coordinates of |
315 | 308 |
///the box were set). |
316 | 309 |
/// |
317 | 310 |
///The coordinates of an empty box are not defined. |
318 | 311 |
bool empty() const { |
319 | 312 |
return _empty; |
320 | 313 |
} |
321 | 314 |
|
322 | 315 |
///Make the box empty |
323 | 316 |
void clear() { |
324 | 317 |
_empty = true; |
325 | 318 |
} |
326 | 319 |
|
327 | 320 |
///Give back the bottom left corner of the box |
328 | 321 |
|
329 | 322 |
///Give back the bottom left corner of the box. |
330 | 323 |
///If the box is empty, then the return value is not defined. |
331 | 324 |
Point<T> bottomLeft() const { |
332 | 325 |
return _bottom_left; |
333 | 326 |
} |
334 | 327 |
|
335 | 328 |
///Set the bottom left corner of the box |
336 | 329 |
|
337 | 330 |
///Set the bottom left corner of the box. |
338 | 331 |
///\pre The box must not be empty. |
339 | 332 |
void bottomLeft(Point<T> p) { |
340 | 333 |
_bottom_left = p; |
341 | 334 |
} |
342 | 335 |
|
343 | 336 |
///Give back the top right corner of the box |
344 | 337 |
|
345 | 338 |
///Give back the top right corner of the box. |
346 | 339 |
///If the box is empty, then the return value is not defined. |
347 | 340 |
Point<T> topRight() const { |
348 | 341 |
return _top_right; |
349 | 342 |
} |
350 | 343 |
|
351 | 344 |
///Set the top right corner of the box |
352 | 345 |
|
353 | 346 |
///Set the top right corner of the box. |
354 | 347 |
///\pre The box must not be empty. |
355 | 348 |
void topRight(Point<T> p) { |
356 | 349 |
_top_right = p; |
357 | 350 |
} |
358 | 351 |
|
359 | 352 |
///Give back the bottom right corner of the box |
360 | 353 |
|
361 | 354 |
///Give back the bottom right corner of the box. |
362 | 355 |
///If the box is empty, then the return value is not defined. |
363 | 356 |
Point<T> bottomRight() const { |
364 | 357 |
return Point<T>(_top_right.x,_bottom_left.y); |
365 | 358 |
} |
366 | 359 |
|
367 | 360 |
///Set the bottom right corner of the box |
368 | 361 |
|
369 | 362 |
///Set the bottom right corner of the box. |
370 | 363 |
///\pre The box must not be empty. |
371 | 364 |
void bottomRight(Point<T> p) { |
372 | 365 |
_top_right.x = p.x; |
373 | 366 |
_bottom_left.y = p.y; |
374 | 367 |
} |
375 | 368 |
|
376 | 369 |
///Give back the top left corner of the box |
377 | 370 |
|
378 | 371 |
///Give back the top left corner of the box. |
379 | 372 |
///If the box is empty, then the return value is not defined. |
380 | 373 |
Point<T> topLeft() const { |
381 | 374 |
return Point<T>(_bottom_left.x,_top_right.y); |
382 | 375 |
} |
383 | 376 |
|
384 | 377 |
///Set the top left corner of the box |
385 | 378 |
|
386 | 379 |
///Set the top left corner of the box. |
387 | 380 |
///\pre The box must not be empty. |
388 | 381 |
void topLeft(Point<T> p) { |
389 | 382 |
_top_right.y = p.y; |
390 | 383 |
_bottom_left.x = p.x; |
391 | 384 |
} |
392 | 385 |
|
393 | 386 |
///Give back the bottom of the box |
394 | 387 |
|
395 | 388 |
///Give back the bottom of the box. |
396 | 389 |
///If the box is empty, then the return value is not defined. |
397 | 390 |
T bottom() const { |
398 | 391 |
return _bottom_left.y; |
399 | 392 |
} |
400 | 393 |
|
401 | 394 |
///Set the bottom of the box |
402 | 395 |
|
403 | 396 |
///Set the bottom of the box. |
404 | 397 |
///\pre The box must not be empty. |
405 | 398 |
void bottom(T t) { |
406 | 399 |
_bottom_left.y = t; |
407 | 400 |
} |
408 | 401 |
|
409 | 402 |
///Give back the top of the box |
410 | 403 |
|
411 | 404 |
///Give back the top of the box. |
412 | 405 |
///If the box is empty, then the return value is not defined. |
413 | 406 |
T top() const { |
414 | 407 |
return _top_right.y; |
415 | 408 |
} |
416 | 409 |
|
417 | 410 |
///Set the top of the box |
418 | 411 |
|
419 | 412 |
///Set the top of the box. |
420 | 413 |
///\pre The box must not be empty. |
421 | 414 |
void top(T t) { |
422 | 415 |
_top_right.y = t; |
423 | 416 |
} |
424 | 417 |
|
425 | 418 |
///Give back the left side of the box |
426 | 419 |
|
427 | 420 |
///Give back the left side of the box. |
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