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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 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 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 |
|
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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 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 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". |
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|
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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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*/ |
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|
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/** |
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@defgroup min_cut Minimum Cut Algorithms |
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@ingroup algs |
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|
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\brief Algorithms for finding minimum cut in graphs. |
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|
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This group contains the algorithms for finding minimum cut in graphs. |
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|
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The \e minimum \e cut \e problem is to find a non-empty and non-complete |
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\f$X\f$ subset of the nodes with minimum overall capacity on |
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outgoing arcs. Formally, there is a \f$G=(V,A)\f$ digraph, a |
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\f$cap: A\rightarrow\mathbf{R}^+_0\f$ capacity function. The minimum |
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cut is the \f$X\f$ solution of the next optimization problem: |
376 | 397 |
|
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\f[ \min_{X \subset V, X\not\in \{\emptyset, V\}} |
378 | 399 |
\sum_{uv\in A, u\in X, v\not\in X}cap(uv) \f] |
379 | 400 |
|
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LEMON contains several algorithms related to minimum cut problems: |
381 | 402 |
|
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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 |
385 | 406 |
calculating minimum cut in undirected graphs. |
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- \ref GomoryHu "Gomory-Hu tree computation" for calculating |
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all-pairs minimum cut in undirected graphs. |
388 | 409 |
|
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If you want to find minimum cut just between two distinict nodes, |
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see the \ref max_flow "maximum flow problem". |
391 | 412 |
*/ |
392 | 413 |
|
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/** |
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@defgroup graph_properties Connectivity and Other Graph Properties |
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@ingroup algs |
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\brief Algorithms for discovering the graph properties |
397 | 418 |
|
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This group contains the algorithms for discovering the graph properties |
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like connectivity, bipartiteness, euler property, simplicity etc. |
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|
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\image html edge_biconnected_components.png |
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\image latex edge_biconnected_components.eps "bi-edge-connected components" width=\textwidth |
403 | 424 |
*/ |
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|
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/** |
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@defgroup planar Planarity Embedding and Drawing |
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@ingroup algs |
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\brief Algorithms for planarity checking, embedding and drawing |
409 | 430 |
|
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This group contains the algorithms for planarity checking, |
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embedding and drawing. |
412 | 433 |
|
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\image html planar.png |
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\image latex planar.eps "Plane graph" width=\textwidth |
415 | 436 |
*/ |
416 | 437 |
|
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/** |
418 | 439 |
@defgroup matching Matching Algorithms |
419 | 440 |
@ingroup algs |
420 | 441 |
\brief Algorithms for finding matchings in graphs and bipartite graphs. |
421 | 442 |
|
422 | 443 |
This group contains the algorithms for calculating |
423 | 444 |
matchings in graphs and bipartite graphs. The general matching problem is |
424 | 445 |
finding a subset of the edges for which each node has at most one incident |
425 | 446 |
edge. |
426 | 447 |
|
427 | 448 |
There are several different algorithms for calculate matchings in |
428 | 449 |
graphs. The matching problems in bipartite graphs are generally |
429 | 450 |
easier than in general graphs. The goal of the matching optimization |
430 | 451 |
can be finding maximum cardinality, maximum weight or minimum cost |
431 | 452 |
matching. The search can be constrained to find perfect or |
432 | 453 |
maximum cardinality matching. |
433 | 454 |
|
434 | 455 |
The matching algorithms implemented in LEMON: |
435 | 456 |
- \ref MaxBipartiteMatching Hopcroft-Karp augmenting path algorithm |
436 | 457 |
for calculating maximum cardinality matching in bipartite graphs. |
437 | 458 |
- \ref PrBipartiteMatching Push-relabel algorithm |
438 | 459 |
for calculating maximum cardinality matching in bipartite graphs. |
439 | 460 |
- \ref MaxWeightedBipartiteMatching |
440 | 461 |
Successive shortest path algorithm for calculating maximum weighted |
441 | 462 |
matching and maximum weighted bipartite matching in bipartite graphs. |
442 | 463 |
- \ref MinCostMaxBipartiteMatching |
443 | 464 |
Successive shortest path algorithm for calculating minimum cost maximum |
444 | 465 |
matching in bipartite graphs. |
445 | 466 |
- \ref MaxMatching Edmond's blossom shrinking algorithm for calculating |
446 | 467 |
maximum cardinality matching in general graphs. |
447 | 468 |
- \ref MaxWeightedMatching Edmond's blossom shrinking algorithm for calculating |
448 | 469 |
maximum weighted matching in general graphs. |
449 | 470 |
- \ref MaxWeightedPerfectMatching |
450 | 471 |
Edmond's blossom shrinking algorithm for calculating maximum weighted |
451 | 472 |
perfect matching in general graphs. |
452 | 473 |
|
453 | 474 |
\image html bipartite_matching.png |
454 | 475 |
\image latex bipartite_matching.eps "Bipartite Matching" width=\textwidth |
455 | 476 |
*/ |
456 | 477 |
|
457 | 478 |
/** |
458 | 479 |
@defgroup spantree Minimum Spanning Tree Algorithms |
459 | 480 |
@ingroup algs |
460 | 481 |
\brief Algorithms for finding minimum cost spanning trees and arborescences. |
461 | 482 |
|
462 | 483 |
This group contains the algorithms for finding minimum cost spanning |
463 | 484 |
trees and arborescences. |
464 | 485 |
*/ |
465 | 486 |
|
466 | 487 |
/** |
467 | 488 |
@defgroup auxalg Auxiliary Algorithms |
468 | 489 |
@ingroup algs |
469 | 490 |
\brief Auxiliary algorithms implemented in LEMON. |
470 | 491 |
|
471 | 492 |
This group contains some algorithms implemented in LEMON |
472 | 493 |
in order to make it easier to implement complex algorithms. |
473 | 494 |
*/ |
474 | 495 |
|
475 | 496 |
/** |
476 | 497 |
@defgroup approx Approximation Algorithms |
477 | 498 |
@ingroup algs |
478 | 499 |
\brief Approximation algorithms. |
479 | 500 |
|
480 | 501 |
This group contains the approximation and heuristic algorithms |
481 | 502 |
implemented in LEMON. |
482 | 503 |
*/ |
483 | 504 |
|
484 | 505 |
/** |
485 | 506 |
@defgroup gen_opt_group General Optimization Tools |
486 | 507 |
\brief This group contains some general optimization frameworks |
487 | 508 |
implemented in LEMON. |
488 | 509 |
|
489 | 510 |
This group contains some general optimization frameworks |
490 | 511 |
implemented in LEMON. |
491 | 512 |
*/ |
492 | 513 |
|
493 | 514 |
/** |
494 | 515 |
@defgroup lp_group Lp and Mip Solvers |
495 | 516 |
@ingroup gen_opt_group |
496 | 517 |
\brief Lp and Mip solver interfaces for LEMON. |
497 | 518 |
|
498 | 519 |
This group contains Lp and Mip solver interfaces for LEMON. The |
499 | 520 |
various LP solvers could be used in the same manner with this |
500 | 521 |
interface. |
501 | 522 |
*/ |
502 | 523 |
|
503 | 524 |
/** |
504 | 525 |
@defgroup lp_utils Tools for Lp and Mip Solvers |
505 | 526 |
@ingroup lp_group |
506 | 527 |
\brief Helper tools to the Lp and Mip solvers. |
507 | 528 |
|
508 | 529 |
This group adds some helper tools to general optimization framework |
509 | 530 |
implemented in LEMON. |
510 | 531 |
*/ |
511 | 532 |
|
512 | 533 |
/** |
513 | 534 |
@defgroup metah Metaheuristics |
514 | 535 |
@ingroup gen_opt_group |
515 | 536 |
\brief Metaheuristics for LEMON library. |
516 | 537 |
|
517 | 538 |
This group contains some metaheuristic optimization tools. |
518 | 539 |
*/ |
519 | 540 |
|
520 | 541 |
/** |
521 | 542 |
@defgroup utils Tools and Utilities |
522 | 543 |
\brief Tools and utilities for programming in LEMON |
523 | 544 |
|
524 | 545 |
Tools and utilities for programming in LEMON. |
525 | 546 |
*/ |
526 | 547 |
|
527 | 548 |
/** |
528 | 549 |
@defgroup gutils Basic Graph Utilities |
529 | 550 |
@ingroup utils |
530 | 551 |
\brief Simple basic graph utilities. |
531 | 552 |
|
532 | 553 |
This group contains some simple basic graph utilities. |
533 | 554 |
*/ |
534 | 555 |
|
535 | 556 |
/** |
536 | 557 |
@defgroup misc Miscellaneous Tools |
537 | 558 |
@ingroup utils |
538 | 559 |
\brief Tools for development, debugging and testing. |
539 | 560 |
|
540 | 561 |
This group contains several useful tools for development, |
541 | 562 |
debugging and testing. |
542 | 563 |
*/ |
543 | 564 |
|
544 | 565 |
/** |
545 | 566 |
@defgroup timecount Time Measuring and Counting |
546 | 567 |
@ingroup misc |
547 | 568 |
\brief Simple tools for measuring the performance of algorithms. |
548 | 569 |
|
549 | 570 |
This group contains simple tools for measuring the performance |
550 | 571 |
of algorithms. |
551 | 572 |
*/ |
552 | 573 |
|
553 | 574 |
/** |
554 | 575 |
@defgroup exceptions Exceptions |
555 | 576 |
@ingroup utils |
556 | 577 |
\brief Exceptions defined in LEMON. |
557 | 578 |
|
558 | 579 |
This group contains the exceptions defined in LEMON. |
559 | 580 |
*/ |
560 | 581 |
|
561 | 582 |
/** |
562 | 583 |
@defgroup io_group Input-Output |
563 | 584 |
\brief Graph Input-Output methods |
564 | 585 |
|
565 | 586 |
This group contains the tools for importing and exporting graphs |
566 | 587 |
and graph related data. Now it supports the \ref lgf-format |
567 | 588 |
"LEMON Graph Format", the \c DIMACS format and the encapsulated |
568 | 589 |
postscript (EPS) format. |
569 | 590 |
*/ |
570 | 591 |
|
571 | 592 |
/** |
572 | 593 |
@defgroup lemon_io LEMON Graph Format |
573 | 594 |
@ingroup io_group |
574 | 595 |
\brief Reading and writing LEMON Graph Format. |
575 | 596 |
|
576 | 597 |
This group contains methods for reading and writing |
577 | 598 |
\ref lgf-format "LEMON Graph Format". |
578 | 599 |
*/ |
579 | 600 |
|
580 | 601 |
/** |
581 | 602 |
@defgroup eps_io Postscript Exporting |
582 | 603 |
@ingroup io_group |
583 | 604 |
\brief General \c EPS drawer and graph exporter |
584 | 605 |
|
585 | 606 |
This group contains general \c EPS drawing methods and special |
586 | 607 |
graph exporting tools. |
587 | 608 |
*/ |
588 | 609 |
|
589 | 610 |
/** |
590 | 611 |
@defgroup dimacs_group DIMACS format |
591 | 612 |
@ingroup io_group |
592 | 613 |
\brief Read and write files in DIMACS format |
593 | 614 |
|
594 | 615 |
Tools to read a digraph from or write it to a file in DIMACS format data. |
595 | 616 |
*/ |
596 | 617 |
|
597 | 618 |
/** |
598 | 619 |
@defgroup nauty_group NAUTY Format |
599 | 620 |
@ingroup io_group |
600 | 621 |
\brief Read \e Nauty format |
601 | 622 |
|
602 | 623 |
Tool to read graphs from \e Nauty format data. |
603 | 624 |
*/ |
604 | 625 |
|
605 | 626 |
/** |
606 | 627 |
@defgroup concept Concepts |
607 | 628 |
\brief Skeleton classes and concept checking classes |
608 | 629 |
|
609 | 630 |
This group contains the data/algorithm skeletons and concept checking |
610 | 631 |
classes implemented in LEMON. |
611 | 632 |
|
612 | 633 |
The purpose of the classes in this group is fourfold. |
613 | 634 |
|
614 | 635 |
- These classes contain the documentations of the %concepts. In order |
615 | 636 |
to avoid document multiplications, an implementation of a concept |
616 | 637 |
simply refers to the corresponding concept class. |
617 | 638 |
|
618 | 639 |
- These classes declare every functions, <tt>typedef</tt>s etc. an |
619 | 640 |
implementation of the %concepts should provide, however completely |
620 | 641 |
without implementations and real data structures behind the |
621 | 642 |
interface. On the other hand they should provide nothing else. All |
622 | 643 |
the algorithms working on a data structure meeting a certain concept |
623 | 644 |
should compile with these classes. (Though it will not run properly, |
624 | 645 |
of course.) In this way it is easily to check if an algorithm |
625 | 646 |
doesn't use any extra feature of a certain implementation. |
626 | 647 |
|
627 | 648 |
- The concept descriptor classes also provide a <em>checker class</em> |
628 | 649 |
that makes it possible to check whether a certain implementation of a |
629 | 650 |
concept indeed provides all the required features. |
630 | 651 |
|
631 | 652 |
- Finally, They can serve as a skeleton of a new implementation of a concept. |
632 | 653 |
*/ |
633 | 654 |
|
634 | 655 |
/** |
635 | 656 |
@defgroup graph_concepts Graph Structure Concepts |
636 | 657 |
@ingroup concept |
637 | 658 |
\brief Skeleton and concept checking classes for graph structures |
638 | 659 |
|
639 | 660 |
This group contains the skeletons and concept checking classes of LEMON's |
640 | 661 |
graph structures and helper classes used to implement these. |
641 | 662 |
*/ |
642 | 663 |
|
643 | 664 |
/** |
644 | 665 |
@defgroup map_concepts Map Concepts |
645 | 666 |
@ingroup concept |
646 | 667 |
\brief Skeleton and concept checking classes for maps |
647 | 668 |
|
648 | 669 |
This group contains the skeletons and concept checking classes of maps. |
649 | 670 |
*/ |
650 | 671 |
|
651 | 672 |
/** |
652 | 673 |
\anchor demoprograms |
653 | 674 |
|
654 | 675 |
@defgroup demos Demo Programs |
655 | 676 |
|
656 | 677 |
Some demo programs are listed here. Their full source codes can be found in |
657 | 678 |
the \c demo subdirectory of the source tree. |
658 | 679 |
|
659 | 680 |
In order to compile them, use the <tt>make demo</tt> or the |
660 | 681 |
<tt>make check</tt> commands. |
661 | 682 |
*/ |
662 | 683 |
|
663 | 684 |
/** |
664 | 685 |
@defgroup tools Standalone Utility Applications |
665 | 686 |
|
666 | 687 |
Some utility applications are listed here. |
667 | 688 |
|
668 | 689 |
The standard compilation procedure (<tt>./configure;make</tt>) will compile |
669 | 690 |
them, as well. |
670 | 691 |
*/ |
671 | 692 |
|
672 | 693 |
} |
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_BIN_HEAP_H |
20 | 20 |
#define LEMON_BIN_HEAP_H |
21 | 21 |
|
22 |
///\ingroup |
|
22 |
///\ingroup heaps |
|
23 | 23 |
///\file |
24 | 24 |
///\brief Binary heap implementation. |
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <utility> |
28 | 28 |
#include <functional> |
29 | 29 |
|
30 | 30 |
namespace lemon { |
31 | 31 |
|
32 |
/// \ingroup |
|
32 |
/// \ingroup heaps |
|
33 | 33 |
/// |
34 | 34 |
/// \brief Binary heap data structure. |
35 | 35 |
/// |
36 | 36 |
/// This class implements the \e binary \e heap data structure. |
37 | 37 |
/// It fully conforms to the \ref concepts::Heap "heap concept". |
38 | 38 |
/// |
39 | 39 |
/// \tparam PR Type of the priorities of the items. |
40 | 40 |
/// \tparam IM A read-writable item map with \c int values, used |
41 | 41 |
/// internally to handle the cross references. |
42 | 42 |
/// \tparam CMP A functor class for comparing the priorities. |
43 | 43 |
/// The default is \c std::less<PR>. |
44 | 44 |
#ifdef DOXYGEN |
45 | 45 |
template <typename PR, typename IM, typename CMP> |
46 | 46 |
#else |
47 | 47 |
template <typename PR, typename IM, typename CMP = std::less<PR> > |
48 | 48 |
#endif |
49 | 49 |
class BinHeap { |
50 | 50 |
public: |
51 | 51 |
|
52 | 52 |
/// Type of the item-int map. |
53 | 53 |
typedef IM ItemIntMap; |
54 | 54 |
/// Type of the priorities. |
55 | 55 |
typedef PR Prio; |
56 | 56 |
/// Type of the items stored in the heap. |
57 | 57 |
typedef typename ItemIntMap::Key Item; |
58 | 58 |
/// Type of the item-priority pairs. |
59 | 59 |
typedef std::pair<Item,Prio> Pair; |
60 | 60 |
/// Functor type for comparing the priorities. |
61 | 61 |
typedef CMP Compare; |
62 | 62 |
|
63 | 63 |
/// \brief Type to represent the states of the items. |
64 | 64 |
/// |
65 | 65 |
/// Each item has a state associated to it. It can be "in heap", |
66 | 66 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
67 | 67 |
/// heap's point of view, but may be useful to the user. |
68 | 68 |
/// |
69 | 69 |
/// The item-int map must be initialized in such way that it assigns |
70 | 70 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
71 | 71 |
enum State { |
72 | 72 |
IN_HEAP = 0, ///< = 0. |
73 | 73 |
PRE_HEAP = -1, ///< = -1. |
74 | 74 |
POST_HEAP = -2 ///< = -2. |
75 | 75 |
}; |
76 | 76 |
|
77 | 77 |
private: |
78 | 78 |
std::vector<Pair> _data; |
79 | 79 |
Compare _comp; |
80 | 80 |
ItemIntMap &_iim; |
81 | 81 |
|
82 | 82 |
public: |
83 | 83 |
|
84 | 84 |
/// \brief Constructor. |
85 | 85 |
/// |
86 | 86 |
/// Constructor. |
87 | 87 |
/// \param map A map that assigns \c int values to the items. |
88 | 88 |
/// It is used internally to handle the cross references. |
89 | 89 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
90 | 90 |
explicit BinHeap(ItemIntMap &map) : _iim(map) {} |
91 | 91 |
|
92 | 92 |
/// \brief Constructor. |
93 | 93 |
/// |
94 | 94 |
/// Constructor. |
95 | 95 |
/// \param map A map that assigns \c int values to the items. |
96 | 96 |
/// It is used internally to handle the cross references. |
97 | 97 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
98 | 98 |
/// \param comp The function object used for comparing the priorities. |
99 | 99 |
BinHeap(ItemIntMap &map, const Compare &comp) |
100 | 100 |
: _iim(map), _comp(comp) {} |
101 | 101 |
|
102 | 102 |
|
103 | 103 |
/// \brief The number of items stored in the heap. |
104 | 104 |
/// |
105 | 105 |
/// This function returns the number of items stored in the heap. |
106 | 106 |
int size() const { return _data.size(); } |
107 | 107 |
|
108 | 108 |
/// \brief Check if the heap is empty. |
109 | 109 |
/// |
110 | 110 |
/// This function returns \c true if the heap is empty. |
111 | 111 |
bool empty() const { return _data.empty(); } |
112 | 112 |
|
113 | 113 |
/// \brief Make the heap empty. |
114 | 114 |
/// |
115 | 115 |
/// This functon makes the heap empty. |
116 | 116 |
/// It does not change the cross reference map. If you want to reuse |
117 | 117 |
/// a heap that is not surely empty, you should first clear it and |
118 | 118 |
/// then you should set the cross reference map to \c PRE_HEAP |
119 | 119 |
/// for each item. |
120 | 120 |
void clear() { |
121 | 121 |
_data.clear(); |
122 | 122 |
} |
123 | 123 |
|
124 | 124 |
private: |
125 | 125 |
static int parent(int i) { return (i-1)/2; } |
126 | 126 |
|
127 | 127 |
static int second_child(int i) { return 2*i+2; } |
128 | 128 |
bool less(const Pair &p1, const Pair &p2) const { |
129 | 129 |
return _comp(p1.second, p2.second); |
130 | 130 |
} |
131 | 131 |
|
132 | 132 |
int bubble_up(int hole, Pair p) { |
133 | 133 |
int par = parent(hole); |
134 | 134 |
while( hole>0 && less(p,_data[par]) ) { |
135 | 135 |
move(_data[par],hole); |
136 | 136 |
hole = par; |
137 | 137 |
par = parent(hole); |
138 | 138 |
} |
139 | 139 |
move(p, hole); |
140 | 140 |
return hole; |
141 | 141 |
} |
142 | 142 |
|
143 | 143 |
int bubble_down(int hole, Pair p, int length) { |
144 | 144 |
int child = second_child(hole); |
145 | 145 |
while(child < length) { |
146 | 146 |
if( less(_data[child-1], _data[child]) ) { |
147 | 147 |
--child; |
148 | 148 |
} |
149 | 149 |
if( !less(_data[child], p) ) |
150 | 150 |
goto ok; |
151 | 151 |
move(_data[child], hole); |
152 | 152 |
hole = child; |
153 | 153 |
child = second_child(hole); |
154 | 154 |
} |
155 | 155 |
child--; |
156 | 156 |
if( child<length && less(_data[child], p) ) { |
157 | 157 |
move(_data[child], hole); |
158 | 158 |
hole=child; |
159 | 159 |
} |
160 | 160 |
ok: |
161 | 161 |
move(p, hole); |
162 | 162 |
return hole; |
163 | 163 |
} |
164 | 164 |
|
165 | 165 |
void move(const Pair &p, int i) { |
166 | 166 |
_data[i] = p; |
167 | 167 |
_iim.set(p.first, i); |
168 | 168 |
} |
169 | 169 |
|
170 | 170 |
public: |
171 | 171 |
|
172 | 172 |
/// \brief Insert a pair of item and priority into the heap. |
173 | 173 |
/// |
174 | 174 |
/// This function inserts \c p.first to the heap with priority |
175 | 175 |
/// \c p.second. |
176 | 176 |
/// \param p The pair to insert. |
177 | 177 |
/// \pre \c p.first must not be stored in the heap. |
178 | 178 |
void push(const Pair &p) { |
179 | 179 |
int n = _data.size(); |
180 | 180 |
_data.resize(n+1); |
181 | 181 |
bubble_up(n, p); |
182 | 182 |
} |
183 | 183 |
|
184 | 184 |
/// \brief Insert an item into the heap with the given priority. |
185 | 185 |
/// |
186 | 186 |
/// This function inserts the given item into the heap with the |
187 | 187 |
/// given priority. |
188 | 188 |
/// \param i The item to insert. |
189 | 189 |
/// \param p The priority of the item. |
190 | 190 |
/// \pre \e i must not be stored in the heap. |
191 | 191 |
void push(const Item &i, const Prio &p) { push(Pair(i,p)); } |
192 | 192 |
|
193 | 193 |
/// \brief Return the item having minimum priority. |
194 | 194 |
/// |
195 | 195 |
/// This function returns the item having minimum priority. |
196 | 196 |
/// \pre The heap must be non-empty. |
197 | 197 |
Item top() const { |
198 | 198 |
return _data[0].first; |
199 | 199 |
} |
200 | 200 |
|
201 | 201 |
/// \brief The minimum priority. |
202 | 202 |
/// |
203 | 203 |
/// This function returns the minimum priority. |
204 | 204 |
/// \pre The heap must be non-empty. |
205 | 205 |
Prio prio() const { |
206 | 206 |
return _data[0].second; |
207 | 207 |
} |
208 | 208 |
|
209 | 209 |
/// \brief Remove the item having minimum priority. |
210 | 210 |
/// |
211 | 211 |
/// This function removes the item having minimum priority. |
212 | 212 |
/// \pre The heap must be non-empty. |
213 | 213 |
void pop() { |
214 | 214 |
int n = _data.size()-1; |
215 | 215 |
_iim.set(_data[0].first, POST_HEAP); |
216 | 216 |
if (n > 0) { |
217 | 217 |
bubble_down(0, _data[n], n); |
218 | 218 |
} |
219 | 219 |
_data.pop_back(); |
220 | 220 |
} |
221 | 221 |
|
222 | 222 |
/// \brief Remove the given item from the heap. |
223 | 223 |
/// |
224 | 224 |
/// This function removes the given item from the heap if it is |
225 | 225 |
/// already stored. |
226 | 226 |
/// \param i The item to delete. |
227 | 227 |
/// \pre \e i must be in the heap. |
228 | 228 |
void erase(const Item &i) { |
229 | 229 |
int h = _iim[i]; |
230 | 230 |
int n = _data.size()-1; |
231 | 231 |
_iim.set(_data[h].first, POST_HEAP); |
232 | 232 |
if( h < n ) { |
233 | 233 |
if ( bubble_up(h, _data[n]) == h) { |
234 | 234 |
bubble_down(h, _data[n], n); |
235 | 235 |
} |
236 | 236 |
} |
237 | 237 |
_data.pop_back(); |
238 | 238 |
} |
239 | 239 |
|
240 | 240 |
/// \brief The priority of the given item. |
241 | 241 |
/// |
242 | 242 |
/// This function returns the priority of the given item. |
243 | 243 |
/// \param i The item. |
244 | 244 |
/// \pre \e i must be in the heap. |
245 | 245 |
Prio operator[](const Item &i) const { |
246 | 246 |
int idx = _iim[i]; |
247 | 247 |
return _data[idx].second; |
248 | 248 |
} |
249 | 249 |
|
250 | 250 |
/// \brief Set the priority of an item or insert it, if it is |
251 | 251 |
/// not stored in the heap. |
252 | 252 |
/// |
253 | 253 |
/// This method sets the priority of the given item if it is |
254 | 254 |
/// already stored in the heap. Otherwise it inserts the given |
255 | 255 |
/// item into the heap with the given priority. |
256 | 256 |
/// \param i The item. |
257 | 257 |
/// \param p The priority. |
258 | 258 |
void set(const Item &i, const Prio &p) { |
259 | 259 |
int idx = _iim[i]; |
260 | 260 |
if( idx < 0 ) { |
261 | 261 |
push(i,p); |
262 | 262 |
} |
263 | 263 |
else if( _comp(p, _data[idx].second) ) { |
264 | 264 |
bubble_up(idx, Pair(i,p)); |
265 | 265 |
} |
266 | 266 |
else { |
267 | 267 |
bubble_down(idx, Pair(i,p), _data.size()); |
268 | 268 |
} |
269 | 269 |
} |
270 | 270 |
|
271 | 271 |
/// \brief Decrease the priority of an item to the given value. |
272 | 272 |
/// |
273 | 273 |
/// This function decreases the priority of an item to the given value. |
274 | 274 |
/// \param i The item. |
275 | 275 |
/// \param p The priority. |
276 | 276 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
277 | 277 |
void decrease(const Item &i, const Prio &p) { |
278 | 278 |
int idx = _iim[i]; |
279 | 279 |
bubble_up(idx, Pair(i,p)); |
280 | 280 |
} |
281 | 281 |
|
282 | 282 |
/// \brief Increase the priority of an item to the given value. |
283 | 283 |
/// |
284 | 284 |
/// This function increases the priority of an item to the given value. |
285 | 285 |
/// \param i The item. |
286 | 286 |
/// \param p The priority. |
287 | 287 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
288 | 288 |
void increase(const Item &i, const Prio &p) { |
289 | 289 |
int idx = _iim[i]; |
290 | 290 |
bubble_down(idx, Pair(i,p), _data.size()); |
291 | 291 |
} |
292 | 292 |
|
293 | 293 |
/// \brief Return the state of an item. |
294 | 294 |
/// |
295 | 295 |
/// This method returns \c PRE_HEAP if the given item has never |
296 | 296 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
297 | 297 |
/// and \c POST_HEAP otherwise. |
298 | 298 |
/// In the latter case it is possible that the item will get back |
299 | 299 |
/// to the heap again. |
300 | 300 |
/// \param i The item. |
301 | 301 |
State state(const Item &i) const { |
302 | 302 |
int s = _iim[i]; |
303 | 303 |
if( s>=0 ) |
304 | 304 |
s=0; |
305 | 305 |
return State(s); |
306 | 306 |
} |
307 | 307 |
|
308 | 308 |
/// \brief Set the state of an item in the heap. |
309 | 309 |
/// |
310 | 310 |
/// This function sets the state of the given item in the heap. |
311 | 311 |
/// It can be used to manually clear the heap when it is important |
312 | 312 |
/// to achive better time complexity. |
313 | 313 |
/// \param i The item. |
314 | 314 |
/// \param st The state. It should not be \c IN_HEAP. |
315 | 315 |
void state(const Item& i, State st) { |
316 | 316 |
switch (st) { |
317 | 317 |
case POST_HEAP: |
318 | 318 |
case PRE_HEAP: |
319 | 319 |
if (state(i) == IN_HEAP) { |
320 | 320 |
erase(i); |
321 | 321 |
} |
322 | 322 |
_iim[i] = st; |
323 | 323 |
break; |
324 | 324 |
case IN_HEAP: |
325 | 325 |
break; |
326 | 326 |
} |
327 | 327 |
} |
328 | 328 |
|
329 | 329 |
/// \brief Replace an item in the heap. |
330 | 330 |
/// |
331 | 331 |
/// This function replaces item \c i with item \c j. |
332 | 332 |
/// Item \c i must be in the heap, while \c j must be out of the heap. |
333 | 333 |
/// After calling this method, item \c i will be out of the |
334 | 334 |
/// heap and \c j will be in the heap with the same prioriority |
335 | 335 |
/// as item \c i had before. |
336 | 336 |
void replace(const Item& i, const Item& j) { |
337 | 337 |
int idx = _iim[i]; |
338 | 338 |
_iim.set(i, _iim[j]); |
339 | 339 |
_iim.set(j, idx); |
340 | 340 |
_data[idx].first = j; |
341 | 341 |
} |
342 | 342 |
|
343 | 343 |
}; // class BinHeap |
344 | 344 |
|
345 | 345 |
} // namespace lemon |
346 | 346 |
|
347 | 347 |
#endif // LEMON_BIN_HEAP_H |
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_BUCKET_HEAP_H |
20 | 20 |
#define LEMON_BUCKET_HEAP_H |
21 | 21 |
|
22 |
///\ingroup |
|
22 |
///\ingroup heaps |
|
23 | 23 |
///\file |
24 | 24 |
///\brief Bucket heap implementation. |
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <utility> |
28 | 28 |
#include <functional> |
29 | 29 |
|
30 | 30 |
namespace lemon { |
31 | 31 |
|
32 | 32 |
namespace _bucket_heap_bits { |
33 | 33 |
|
34 | 34 |
template <bool MIN> |
35 | 35 |
struct DirectionTraits { |
36 | 36 |
static bool less(int left, int right) { |
37 | 37 |
return left < right; |
38 | 38 |
} |
39 | 39 |
static void increase(int& value) { |
40 | 40 |
++value; |
41 | 41 |
} |
42 | 42 |
}; |
43 | 43 |
|
44 | 44 |
template <> |
45 | 45 |
struct DirectionTraits<false> { |
46 | 46 |
static bool less(int left, int right) { |
47 | 47 |
return left > right; |
48 | 48 |
} |
49 | 49 |
static void increase(int& value) { |
50 | 50 |
--value; |
51 | 51 |
} |
52 | 52 |
}; |
53 | 53 |
|
54 | 54 |
} |
55 | 55 |
|
56 |
/// \ingroup |
|
56 |
/// \ingroup heaps |
|
57 | 57 |
/// |
58 | 58 |
/// \brief Bucket heap data structure. |
59 | 59 |
/// |
60 | 60 |
/// This class implements the \e bucket \e heap data structure. |
61 | 61 |
/// It practically conforms to the \ref concepts::Heap "heap concept", |
62 | 62 |
/// but it has some limitations. |
63 | 63 |
/// |
64 | 64 |
/// The bucket heap is a very simple structure. It can store only |
65 | 65 |
/// \c int priorities and it maintains a list of items for each priority |
66 | 66 |
/// in the range <tt>[0..C)</tt>. So it should only be used when the |
67 | 67 |
/// priorities are small. It is not intended to use as a Dijkstra heap. |
68 | 68 |
/// |
69 | 69 |
/// \tparam IM A read-writable item map with \c int values, used |
70 | 70 |
/// internally to handle the cross references. |
71 | 71 |
/// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap. |
72 | 72 |
/// The default is \e min-heap. If this parameter is set to \c false, |
73 | 73 |
/// then the comparison is reversed, so the top(), prio() and pop() |
74 | 74 |
/// functions deal with the item having maximum priority instead of the |
75 | 75 |
/// minimum. |
76 | 76 |
/// |
77 | 77 |
/// \sa SimpleBucketHeap |
78 | 78 |
template <typename IM, bool MIN = true> |
79 | 79 |
class BucketHeap { |
80 | 80 |
|
81 | 81 |
public: |
82 | 82 |
|
83 | 83 |
/// Type of the item-int map. |
84 | 84 |
typedef IM ItemIntMap; |
85 | 85 |
/// Type of the priorities. |
86 | 86 |
typedef int Prio; |
87 | 87 |
/// Type of the items stored in the heap. |
88 | 88 |
typedef typename ItemIntMap::Key Item; |
89 | 89 |
/// Type of the item-priority pairs. |
90 | 90 |
typedef std::pair<Item,Prio> Pair; |
91 | 91 |
|
92 | 92 |
private: |
93 | 93 |
|
94 | 94 |
typedef _bucket_heap_bits::DirectionTraits<MIN> Direction; |
95 | 95 |
|
96 | 96 |
public: |
97 | 97 |
|
98 | 98 |
/// \brief Type to represent the states of the items. |
99 | 99 |
/// |
100 | 100 |
/// Each item has a state associated to it. It can be "in heap", |
101 | 101 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
102 | 102 |
/// heap's point of view, but may be useful to the user. |
103 | 103 |
/// |
104 | 104 |
/// The item-int map must be initialized in such way that it assigns |
105 | 105 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
106 | 106 |
enum State { |
107 | 107 |
IN_HEAP = 0, ///< = 0. |
108 | 108 |
PRE_HEAP = -1, ///< = -1. |
109 | 109 |
POST_HEAP = -2 ///< = -2. |
110 | 110 |
}; |
111 | 111 |
|
112 | 112 |
public: |
113 | 113 |
|
114 | 114 |
/// \brief Constructor. |
115 | 115 |
/// |
116 | 116 |
/// Constructor. |
117 | 117 |
/// \param map A map that assigns \c int values to the items. |
118 | 118 |
/// It is used internally to handle the cross references. |
119 | 119 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
120 | 120 |
explicit BucketHeap(ItemIntMap &map) : _iim(map), _minimum(0) {} |
121 | 121 |
|
122 | 122 |
/// \brief The number of items stored in the heap. |
123 | 123 |
/// |
124 | 124 |
/// This function returns the number of items stored in the heap. |
125 | 125 |
int size() const { return _data.size(); } |
126 | 126 |
|
127 | 127 |
/// \brief Check if the heap is empty. |
128 | 128 |
/// |
129 | 129 |
/// This function returns \c true if the heap is empty. |
130 | 130 |
bool empty() const { return _data.empty(); } |
131 | 131 |
|
132 | 132 |
/// \brief Make the heap empty. |
133 | 133 |
/// |
134 | 134 |
/// This functon makes the heap empty. |
135 | 135 |
/// It does not change the cross reference map. If you want to reuse |
136 | 136 |
/// a heap that is not surely empty, you should first clear it and |
137 | 137 |
/// then you should set the cross reference map to \c PRE_HEAP |
138 | 138 |
/// for each item. |
139 | 139 |
void clear() { |
140 | 140 |
_data.clear(); _first.clear(); _minimum = 0; |
141 | 141 |
} |
142 | 142 |
|
143 | 143 |
private: |
144 | 144 |
|
145 | 145 |
void relocate_last(int idx) { |
146 | 146 |
if (idx + 1 < int(_data.size())) { |
147 | 147 |
_data[idx] = _data.back(); |
148 | 148 |
if (_data[idx].prev != -1) { |
149 | 149 |
_data[_data[idx].prev].next = idx; |
150 | 150 |
} else { |
151 | 151 |
_first[_data[idx].value] = idx; |
152 | 152 |
} |
153 | 153 |
if (_data[idx].next != -1) { |
154 | 154 |
_data[_data[idx].next].prev = idx; |
155 | 155 |
} |
156 | 156 |
_iim[_data[idx].item] = idx; |
157 | 157 |
} |
158 | 158 |
_data.pop_back(); |
159 | 159 |
} |
160 | 160 |
|
161 | 161 |
void unlace(int idx) { |
162 | 162 |
if (_data[idx].prev != -1) { |
163 | 163 |
_data[_data[idx].prev].next = _data[idx].next; |
164 | 164 |
} else { |
165 | 165 |
_first[_data[idx].value] = _data[idx].next; |
166 | 166 |
} |
167 | 167 |
if (_data[idx].next != -1) { |
168 | 168 |
_data[_data[idx].next].prev = _data[idx].prev; |
169 | 169 |
} |
170 | 170 |
} |
171 | 171 |
|
172 | 172 |
void lace(int idx) { |
173 | 173 |
if (int(_first.size()) <= _data[idx].value) { |
174 | 174 |
_first.resize(_data[idx].value + 1, -1); |
175 | 175 |
} |
176 | 176 |
_data[idx].next = _first[_data[idx].value]; |
177 | 177 |
if (_data[idx].next != -1) { |
178 | 178 |
_data[_data[idx].next].prev = idx; |
179 | 179 |
} |
180 | 180 |
_first[_data[idx].value] = idx; |
181 | 181 |
_data[idx].prev = -1; |
182 | 182 |
} |
183 | 183 |
|
184 | 184 |
public: |
185 | 185 |
|
186 | 186 |
/// \brief Insert a pair of item and priority into the heap. |
187 | 187 |
/// |
188 | 188 |
/// This function inserts \c p.first to the heap with priority |
189 | 189 |
/// \c p.second. |
190 | 190 |
/// \param p The pair to insert. |
191 | 191 |
/// \pre \c p.first must not be stored in the heap. |
192 | 192 |
void push(const Pair& p) { |
193 | 193 |
push(p.first, p.second); |
194 | 194 |
} |
195 | 195 |
|
196 | 196 |
/// \brief Insert an item into the heap with the given priority. |
197 | 197 |
/// |
198 | 198 |
/// This function inserts the given item into the heap with the |
199 | 199 |
/// given priority. |
200 | 200 |
/// \param i The item to insert. |
201 | 201 |
/// \param p The priority of the item. |
202 | 202 |
/// \pre \e i must not be stored in the heap. |
203 | 203 |
void push(const Item &i, const Prio &p) { |
204 | 204 |
int idx = _data.size(); |
205 | 205 |
_iim[i] = idx; |
206 | 206 |
_data.push_back(BucketItem(i, p)); |
207 | 207 |
lace(idx); |
208 | 208 |
if (Direction::less(p, _minimum)) { |
209 | 209 |
_minimum = p; |
210 | 210 |
} |
211 | 211 |
} |
212 | 212 |
|
213 | 213 |
/// \brief Return the item having minimum priority. |
214 | 214 |
/// |
215 | 215 |
/// This function returns the item having minimum priority. |
216 | 216 |
/// \pre The heap must be non-empty. |
217 | 217 |
Item top() const { |
218 | 218 |
while (_first[_minimum] == -1) { |
219 | 219 |
Direction::increase(_minimum); |
220 | 220 |
} |
221 | 221 |
return _data[_first[_minimum]].item; |
222 | 222 |
} |
223 | 223 |
|
224 | 224 |
/// \brief The minimum priority. |
225 | 225 |
/// |
226 | 226 |
/// This function returns the minimum priority. |
227 | 227 |
/// \pre The heap must be non-empty. |
228 | 228 |
Prio prio() const { |
229 | 229 |
while (_first[_minimum] == -1) { |
230 | 230 |
Direction::increase(_minimum); |
231 | 231 |
} |
232 | 232 |
return _minimum; |
233 | 233 |
} |
234 | 234 |
|
235 | 235 |
/// \brief Remove the item having minimum priority. |
236 | 236 |
/// |
237 | 237 |
/// This function removes the item having minimum priority. |
238 | 238 |
/// \pre The heap must be non-empty. |
239 | 239 |
void pop() { |
240 | 240 |
while (_first[_minimum] == -1) { |
241 | 241 |
Direction::increase(_minimum); |
242 | 242 |
} |
243 | 243 |
int idx = _first[_minimum]; |
244 | 244 |
_iim[_data[idx].item] = -2; |
245 | 245 |
unlace(idx); |
246 | 246 |
relocate_last(idx); |
247 | 247 |
} |
248 | 248 |
|
249 | 249 |
/// \brief Remove the given item from the heap. |
250 | 250 |
/// |
251 | 251 |
/// This function removes the given item from the heap if it is |
252 | 252 |
/// already stored. |
253 | 253 |
/// \param i The item to delete. |
254 | 254 |
/// \pre \e i must be in the heap. |
255 | 255 |
void erase(const Item &i) { |
256 | 256 |
int idx = _iim[i]; |
257 | 257 |
_iim[_data[idx].item] = -2; |
258 | 258 |
unlace(idx); |
259 | 259 |
relocate_last(idx); |
260 | 260 |
} |
261 | 261 |
|
262 | 262 |
/// \brief The priority of the given item. |
263 | 263 |
/// |
264 | 264 |
/// This function returns the priority of the given item. |
265 | 265 |
/// \param i The item. |
266 | 266 |
/// \pre \e i must be in the heap. |
267 | 267 |
Prio operator[](const Item &i) const { |
268 | 268 |
int idx = _iim[i]; |
269 | 269 |
return _data[idx].value; |
270 | 270 |
} |
271 | 271 |
|
272 | 272 |
/// \brief Set the priority of an item or insert it, if it is |
273 | 273 |
/// not stored in the heap. |
274 | 274 |
/// |
275 | 275 |
/// This method sets the priority of the given item if it is |
276 | 276 |
/// already stored in the heap. Otherwise it inserts the given |
277 | 277 |
/// item into the heap with the given priority. |
278 | 278 |
/// \param i The item. |
279 | 279 |
/// \param p The priority. |
280 | 280 |
void set(const Item &i, const Prio &p) { |
281 | 281 |
int idx = _iim[i]; |
282 | 282 |
if (idx < 0) { |
283 | 283 |
push(i, p); |
284 | 284 |
} else if (Direction::less(p, _data[idx].value)) { |
285 | 285 |
decrease(i, p); |
286 | 286 |
} else { |
287 | 287 |
increase(i, p); |
288 | 288 |
} |
289 | 289 |
} |
290 | 290 |
|
291 | 291 |
/// \brief Decrease the priority of an item to the given value. |
292 | 292 |
/// |
293 | 293 |
/// This function decreases the priority of an item to the given value. |
294 | 294 |
/// \param i The item. |
295 | 295 |
/// \param p The priority. |
296 | 296 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
297 | 297 |
void decrease(const Item &i, const Prio &p) { |
298 | 298 |
int idx = _iim[i]; |
299 | 299 |
unlace(idx); |
300 | 300 |
_data[idx].value = p; |
301 | 301 |
if (Direction::less(p, _minimum)) { |
302 | 302 |
_minimum = p; |
303 | 303 |
} |
304 | 304 |
lace(idx); |
305 | 305 |
} |
306 | 306 |
|
307 | 307 |
/// \brief Increase the priority of an item to the given value. |
308 | 308 |
/// |
309 | 309 |
/// This function increases the priority of an item to the given value. |
310 | 310 |
/// \param i The item. |
311 | 311 |
/// \param p The priority. |
312 | 312 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
313 | 313 |
void increase(const Item &i, const Prio &p) { |
314 | 314 |
int idx = _iim[i]; |
315 | 315 |
unlace(idx); |
316 | 316 |
_data[idx].value = p; |
317 | 317 |
lace(idx); |
318 | 318 |
} |
319 | 319 |
|
320 | 320 |
/// \brief Return the state of an item. |
321 | 321 |
/// |
322 | 322 |
/// This method returns \c PRE_HEAP if the given item has never |
323 | 323 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
324 | 324 |
/// and \c POST_HEAP otherwise. |
325 | 325 |
/// In the latter case it is possible that the item will get back |
326 | 326 |
/// to the heap again. |
327 | 327 |
/// \param i The item. |
328 | 328 |
State state(const Item &i) const { |
329 | 329 |
int idx = _iim[i]; |
330 | 330 |
if (idx >= 0) idx = 0; |
331 | 331 |
return State(idx); |
332 | 332 |
} |
333 | 333 |
|
334 | 334 |
/// \brief Set the state of an item in the heap. |
335 | 335 |
/// |
336 | 336 |
/// This function sets the state of the given item in the heap. |
337 | 337 |
/// It can be used to manually clear the heap when it is important |
338 | 338 |
/// to achive better time complexity. |
339 | 339 |
/// \param i The item. |
340 | 340 |
/// \param st The state. It should not be \c IN_HEAP. |
341 | 341 |
void state(const Item& i, State st) { |
342 | 342 |
switch (st) { |
343 | 343 |
case POST_HEAP: |
344 | 344 |
case PRE_HEAP: |
345 | 345 |
if (state(i) == IN_HEAP) { |
346 | 346 |
erase(i); |
347 | 347 |
} |
348 | 348 |
_iim[i] = st; |
349 | 349 |
break; |
350 | 350 |
case IN_HEAP: |
351 | 351 |
break; |
352 | 352 |
} |
353 | 353 |
} |
354 | 354 |
|
355 | 355 |
private: |
356 | 356 |
|
357 | 357 |
struct BucketItem { |
358 | 358 |
BucketItem(const Item& _item, int _value) |
359 | 359 |
: item(_item), value(_value) {} |
360 | 360 |
|
361 | 361 |
Item item; |
362 | 362 |
int value; |
363 | 363 |
|
364 | 364 |
int prev, next; |
365 | 365 |
}; |
366 | 366 |
|
367 | 367 |
ItemIntMap& _iim; |
368 | 368 |
std::vector<int> _first; |
369 | 369 |
std::vector<BucketItem> _data; |
370 | 370 |
mutable int _minimum; |
371 | 371 |
|
372 | 372 |
}; // class BucketHeap |
373 | 373 |
|
374 |
/// \ingroup |
|
374 |
/// \ingroup heaps |
|
375 | 375 |
/// |
376 | 376 |
/// \brief Simplified bucket heap data structure. |
377 | 377 |
/// |
378 | 378 |
/// This class implements a simplified \e bucket \e heap data |
379 | 379 |
/// structure. It does not provide some functionality, but it is |
380 | 380 |
/// faster and simpler than BucketHeap. The main difference is |
381 | 381 |
/// that BucketHeap stores a doubly-linked list for each key while |
382 | 382 |
/// this class stores only simply-linked lists. It supports erasing |
383 | 383 |
/// only for the item having minimum priority and it does not support |
384 | 384 |
/// key increasing and decreasing. |
385 | 385 |
/// |
386 | 386 |
/// Note that this implementation does not conform to the |
387 | 387 |
/// \ref concepts::Heap "heap concept" due to the lack of some |
388 | 388 |
/// functionality. |
389 | 389 |
/// |
390 | 390 |
/// \tparam IM A read-writable item map with \c int values, used |
391 | 391 |
/// internally to handle the cross references. |
392 | 392 |
/// \tparam MIN Indicate if the heap is a \e min-heap or a \e max-heap. |
393 | 393 |
/// The default is \e min-heap. If this parameter is set to \c false, |
394 | 394 |
/// then the comparison is reversed, so the top(), prio() and pop() |
395 | 395 |
/// functions deal with the item having maximum priority instead of the |
396 | 396 |
/// minimum. |
397 | 397 |
/// |
398 | 398 |
/// \sa BucketHeap |
399 | 399 |
template <typename IM, bool MIN = true > |
400 | 400 |
class SimpleBucketHeap { |
401 | 401 |
|
402 | 402 |
public: |
403 | 403 |
|
404 | 404 |
/// Type of the item-int map. |
405 | 405 |
typedef IM ItemIntMap; |
406 | 406 |
/// Type of the priorities. |
407 | 407 |
typedef int Prio; |
408 | 408 |
/// Type of the items stored in the heap. |
409 | 409 |
typedef typename ItemIntMap::Key Item; |
410 | 410 |
/// Type of the item-priority pairs. |
411 | 411 |
typedef std::pair<Item,Prio> Pair; |
412 | 412 |
|
413 | 413 |
private: |
414 | 414 |
|
415 | 415 |
typedef _bucket_heap_bits::DirectionTraits<MIN> Direction; |
416 | 416 |
|
417 | 417 |
public: |
418 | 418 |
|
419 | 419 |
/// \brief Type to represent the states of the items. |
420 | 420 |
/// |
421 | 421 |
/// Each item has a state associated to it. It can be "in heap", |
422 | 422 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
423 | 423 |
/// heap's point of view, but may be useful to the user. |
424 | 424 |
/// |
425 | 425 |
/// The item-int map must be initialized in such way that it assigns |
426 | 426 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
427 | 427 |
enum State { |
428 | 428 |
IN_HEAP = 0, ///< = 0. |
429 | 429 |
PRE_HEAP = -1, ///< = -1. |
430 | 430 |
POST_HEAP = -2 ///< = -2. |
431 | 431 |
}; |
432 | 432 |
|
433 | 433 |
public: |
434 | 434 |
|
435 | 435 |
/// \brief Constructor. |
436 | 436 |
/// |
437 | 437 |
/// Constructor. |
438 | 438 |
/// \param map A map that assigns \c int values to the items. |
439 | 439 |
/// It is used internally to handle the cross references. |
440 | 440 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
441 | 441 |
explicit SimpleBucketHeap(ItemIntMap &map) |
442 | 442 |
: _iim(map), _free(-1), _num(0), _minimum(0) {} |
443 | 443 |
|
444 | 444 |
/// \brief The number of items stored in the heap. |
445 | 445 |
/// |
446 | 446 |
/// This function returns the number of items stored in the heap. |
447 | 447 |
int size() const { return _num; } |
448 | 448 |
|
449 | 449 |
/// \brief Check if the heap is empty. |
450 | 450 |
/// |
451 | 451 |
/// This function returns \c true if the heap is empty. |
452 | 452 |
bool empty() const { return _num == 0; } |
453 | 453 |
|
454 | 454 |
/// \brief Make the heap empty. |
455 | 455 |
/// |
456 | 456 |
/// This functon makes the heap empty. |
457 | 457 |
/// It does not change the cross reference map. If you want to reuse |
458 | 458 |
/// a heap that is not surely empty, you should first clear it and |
459 | 459 |
/// then you should set the cross reference map to \c PRE_HEAP |
460 | 460 |
/// for each item. |
461 | 461 |
void clear() { |
462 | 462 |
_data.clear(); _first.clear(); _free = -1; _num = 0; _minimum = 0; |
463 | 463 |
} |
464 | 464 |
|
465 | 465 |
/// \brief Insert a pair of item and priority into the heap. |
466 | 466 |
/// |
467 | 467 |
/// This function inserts \c p.first to the heap with priority |
468 | 468 |
/// \c p.second. |
469 | 469 |
/// \param p The pair to insert. |
470 | 470 |
/// \pre \c p.first must not be stored in the heap. |
471 | 471 |
void push(const Pair& p) { |
472 | 472 |
push(p.first, p.second); |
473 | 473 |
} |
474 | 474 |
|
475 | 475 |
/// \brief Insert an item into the heap with the given priority. |
476 | 476 |
/// |
477 | 477 |
/// This function inserts the given item into the heap with the |
478 | 478 |
/// given priority. |
479 | 479 |
/// \param i The item to insert. |
480 | 480 |
/// \param p The priority of the item. |
481 | 481 |
/// \pre \e i must not be stored in the heap. |
482 | 482 |
void push(const Item &i, const Prio &p) { |
483 | 483 |
int idx; |
484 | 484 |
if (_free == -1) { |
485 | 485 |
idx = _data.size(); |
486 | 486 |
_data.push_back(BucketItem(i)); |
487 | 487 |
} else { |
488 | 488 |
idx = _free; |
489 | 489 |
_free = _data[idx].next; |
490 | 490 |
_data[idx].item = i; |
491 | 491 |
} |
492 | 492 |
_iim[i] = idx; |
493 | 493 |
if (p >= int(_first.size())) _first.resize(p + 1, -1); |
494 | 494 |
_data[idx].next = _first[p]; |
495 | 495 |
_first[p] = idx; |
496 | 496 |
if (Direction::less(p, _minimum)) { |
497 | 497 |
_minimum = p; |
498 | 498 |
} |
499 | 499 |
++_num; |
500 | 500 |
} |
501 | 501 |
|
502 | 502 |
/// \brief Return the item having minimum priority. |
503 | 503 |
/// |
504 | 504 |
/// This function returns the item having minimum priority. |
505 | 505 |
/// \pre The heap must be non-empty. |
506 | 506 |
Item top() const { |
507 | 507 |
while (_first[_minimum] == -1) { |
508 | 508 |
Direction::increase(_minimum); |
509 | 509 |
} |
510 | 510 |
return _data[_first[_minimum]].item; |
511 | 511 |
} |
512 | 512 |
|
513 | 513 |
/// \brief The minimum priority. |
514 | 514 |
/// |
515 | 515 |
/// This function returns the minimum priority. |
516 | 516 |
/// \pre The heap must be non-empty. |
517 | 517 |
Prio prio() const { |
518 | 518 |
while (_first[_minimum] == -1) { |
519 | 519 |
Direction::increase(_minimum); |
520 | 520 |
} |
521 | 521 |
return _minimum; |
522 | 522 |
} |
523 | 523 |
|
524 | 524 |
/// \brief Remove the item having minimum priority. |
525 | 525 |
/// |
526 | 526 |
/// This function removes the item having minimum priority. |
527 | 527 |
/// \pre The heap must be non-empty. |
528 | 528 |
void pop() { |
529 | 529 |
while (_first[_minimum] == -1) { |
530 | 530 |
Direction::increase(_minimum); |
531 | 531 |
} |
532 | 532 |
int idx = _first[_minimum]; |
533 | 533 |
_iim[_data[idx].item] = -2; |
534 | 534 |
_first[_minimum] = _data[idx].next; |
535 | 535 |
_data[idx].next = _free; |
536 | 536 |
_free = idx; |
537 | 537 |
--_num; |
538 | 538 |
} |
539 | 539 |
|
540 | 540 |
/// \brief The priority of the given item. |
541 | 541 |
/// |
542 | 542 |
/// This function returns the priority of the given item. |
543 | 543 |
/// \param i The item. |
544 | 544 |
/// \pre \e i must be in the heap. |
545 | 545 |
/// \warning This operator is not a constant time function because |
546 | 546 |
/// it scans the whole data structure to find the proper value. |
547 | 547 |
Prio operator[](const Item &i) const { |
548 | 548 |
for (int k = 0; k < int(_first.size()); ++k) { |
549 | 549 |
int idx = _first[k]; |
550 | 550 |
while (idx != -1) { |
551 | 551 |
if (_data[idx].item == i) { |
552 | 552 |
return k; |
553 | 553 |
} |
554 | 554 |
idx = _data[idx].next; |
555 | 555 |
} |
556 | 556 |
} |
557 | 557 |
return -1; |
558 | 558 |
} |
559 | 559 |
|
560 | 560 |
/// \brief Return the state of an item. |
561 | 561 |
/// |
562 | 562 |
/// This method returns \c PRE_HEAP if the given item has never |
563 | 563 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
564 | 564 |
/// and \c POST_HEAP otherwise. |
565 | 565 |
/// In the latter case it is possible that the item will get back |
566 | 566 |
/// to the heap again. |
567 | 567 |
/// \param i The item. |
568 | 568 |
State state(const Item &i) const { |
569 | 569 |
int idx = _iim[i]; |
570 | 570 |
if (idx >= 0) idx = 0; |
571 | 571 |
return State(idx); |
572 | 572 |
} |
573 | 573 |
|
574 | 574 |
private: |
575 | 575 |
|
576 | 576 |
struct BucketItem { |
577 | 577 |
BucketItem(const Item& _item) |
578 | 578 |
: item(_item) {} |
579 | 579 |
|
580 | 580 |
Item item; |
581 | 581 |
int next; |
582 | 582 |
}; |
583 | 583 |
|
584 | 584 |
ItemIntMap& _iim; |
585 | 585 |
std::vector<int> _first; |
586 | 586 |
std::vector<BucketItem> _data; |
587 | 587 |
int _free, _num; |
588 | 588 |
mutable int _minimum; |
589 | 589 |
|
590 | 590 |
}; // class SimpleBucketHeap |
591 | 591 |
|
592 | 592 |
} |
593 | 593 |
|
594 | 594 |
#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_HEAP_H |
20 | 20 |
#define LEMON_CONCEPTS_HEAP_H |
21 | 21 |
|
22 | 22 |
///\ingroup concept |
23 | 23 |
///\file |
24 | 24 |
///\brief The concept of heaps. |
25 | 25 |
|
26 | 26 |
#include <lemon/core.h> |
27 | 27 |
#include <lemon/concept_check.h> |
28 | 28 |
|
29 | 29 |
namespace lemon { |
30 | 30 |
|
31 | 31 |
namespace concepts { |
32 | 32 |
|
33 | 33 |
/// \addtogroup concept |
34 | 34 |
/// @{ |
35 | 35 |
|
36 | 36 |
/// \brief The heap concept. |
37 | 37 |
/// |
38 | 38 |
/// This concept class describes the main interface of heaps. |
39 |
/// The various heap structures are efficient |
|
39 |
/// The various \ref heaps "heap structures" are efficient |
|
40 | 40 |
/// implementations of the abstract data type \e priority \e queue. |
41 | 41 |
/// They store items with specified values called \e priorities |
42 | 42 |
/// in such a way that finding and removing the item with minimum |
43 | 43 |
/// priority are efficient. The basic operations are adding and |
44 | 44 |
/// erasing items, changing the priority of an item, etc. |
45 | 45 |
/// |
46 | 46 |
/// Heaps are crucial in several algorithms, such as Dijkstra and Prim. |
47 | 47 |
/// Any class that conforms to this concept can be used easily in such |
48 | 48 |
/// algorithms. |
49 | 49 |
/// |
50 | 50 |
/// \tparam PR Type of the priorities of the items. |
51 | 51 |
/// \tparam IM A read-writable item map with \c int values, used |
52 | 52 |
/// internally to handle the cross references. |
53 | 53 |
/// \tparam CMP A functor class for comparing the priorities. |
54 | 54 |
/// The default is \c std::less<PR>. |
55 | 55 |
#ifdef DOXYGEN |
56 | 56 |
template <typename PR, typename IM, typename CMP> |
57 | 57 |
#else |
58 | 58 |
template <typename PR, typename IM, typename CMP = std::less<PR> > |
59 | 59 |
#endif |
60 | 60 |
class Heap { |
61 | 61 |
public: |
62 | 62 |
|
63 | 63 |
/// Type of the item-int map. |
64 | 64 |
typedef IM ItemIntMap; |
65 | 65 |
/// Type of the priorities. |
66 | 66 |
typedef PR Prio; |
67 | 67 |
/// Type of the items stored in the heap. |
68 | 68 |
typedef typename ItemIntMap::Key Item; |
69 | 69 |
|
70 | 70 |
/// \brief Type to represent the states of the items. |
71 | 71 |
/// |
72 | 72 |
/// Each item has a state associated to it. It can be "in heap", |
73 | 73 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
74 | 74 |
/// heap's point of view, but may be useful to the user. |
75 | 75 |
/// |
76 | 76 |
/// The item-int map must be initialized in such way that it assigns |
77 | 77 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
78 | 78 |
enum State { |
79 | 79 |
IN_HEAP = 0, ///< = 0. The "in heap" state constant. |
80 | 80 |
PRE_HEAP = -1, ///< = -1. The "pre-heap" state constant. |
81 | 81 |
POST_HEAP = -2 ///< = -2. The "post-heap" state constant. |
82 | 82 |
}; |
83 | 83 |
|
84 | 84 |
/// \brief Constructor. |
85 | 85 |
/// |
86 | 86 |
/// Constructor. |
87 | 87 |
/// \param map A map that assigns \c int values to keys of type |
88 | 88 |
/// \c Item. It is used internally by the heap implementations to |
89 | 89 |
/// handle the cross references. The assigned value must be |
90 | 90 |
/// \c PRE_HEAP (<tt>-1</tt>) for each item. |
91 | 91 |
explicit Heap(ItemIntMap &map) {} |
92 | 92 |
|
93 | 93 |
/// \brief Constructor. |
94 | 94 |
/// |
95 | 95 |
/// Constructor. |
96 | 96 |
/// \param map A map that assigns \c int values to keys of type |
97 | 97 |
/// \c Item. It is used internally by the heap implementations to |
98 | 98 |
/// handle the cross references. The assigned value must be |
99 | 99 |
/// \c PRE_HEAP (<tt>-1</tt>) for each item. |
100 | 100 |
/// \param comp The function object used for comparing the priorities. |
101 | 101 |
explicit Heap(ItemIntMap &map, const CMP &comp) {} |
102 | 102 |
|
103 | 103 |
/// \brief The number of items stored in the heap. |
104 | 104 |
/// |
105 | 105 |
/// This function returns the number of items stored in the heap. |
106 | 106 |
int size() const { return 0; } |
107 | 107 |
|
108 | 108 |
/// \brief Check if the heap is empty. |
109 | 109 |
/// |
110 | 110 |
/// This function returns \c true if the heap is empty. |
111 | 111 |
bool empty() const { return false; } |
112 | 112 |
|
113 | 113 |
/// \brief Make the heap empty. |
114 | 114 |
/// |
115 | 115 |
/// This functon makes the heap empty. |
116 | 116 |
/// It does not change the cross reference map. If you want to reuse |
117 | 117 |
/// a heap that is not surely empty, you should first clear it and |
118 | 118 |
/// then you should set the cross reference map to \c PRE_HEAP |
119 | 119 |
/// for each item. |
120 | 120 |
void clear() {} |
121 | 121 |
|
122 | 122 |
/// \brief Insert an item into the heap with the given priority. |
123 | 123 |
/// |
124 | 124 |
/// This function inserts the given item into the heap with the |
125 | 125 |
/// given priority. |
126 | 126 |
/// \param i The item to insert. |
127 | 127 |
/// \param p The priority of the item. |
128 | 128 |
/// \pre \e i must not be stored in the heap. |
129 | 129 |
void push(const Item &i, const Prio &p) {} |
130 | 130 |
|
131 | 131 |
/// \brief Return the item having minimum priority. |
132 | 132 |
/// |
133 | 133 |
/// This function returns the item having minimum priority. |
134 | 134 |
/// \pre The heap must be non-empty. |
135 | 135 |
Item top() const {} |
136 | 136 |
|
137 | 137 |
/// \brief The minimum priority. |
138 | 138 |
/// |
139 | 139 |
/// This function returns the minimum priority. |
140 | 140 |
/// \pre The heap must be non-empty. |
141 | 141 |
Prio prio() const {} |
142 | 142 |
|
143 | 143 |
/// \brief Remove the item having minimum priority. |
144 | 144 |
/// |
145 | 145 |
/// This function removes the item having minimum priority. |
146 | 146 |
/// \pre The heap must be non-empty. |
147 | 147 |
void pop() {} |
148 | 148 |
|
149 | 149 |
/// \brief Remove the given item from the heap. |
150 | 150 |
/// |
151 | 151 |
/// This function removes the given item from the heap if it is |
152 | 152 |
/// already stored. |
153 | 153 |
/// \param i The item to delete. |
154 | 154 |
/// \pre \e i must be in the heap. |
155 | 155 |
void erase(const Item &i) {} |
156 | 156 |
|
157 | 157 |
/// \brief The priority of the given item. |
158 | 158 |
/// |
159 | 159 |
/// This function returns the priority of the given item. |
160 | 160 |
/// \param i The item. |
161 | 161 |
/// \pre \e i must be in the heap. |
162 | 162 |
Prio operator[](const Item &i) const {} |
163 | 163 |
|
164 | 164 |
/// \brief Set the priority of an item or insert it, if it is |
165 | 165 |
/// not stored in the heap. |
166 | 166 |
/// |
167 | 167 |
/// This method sets the priority of the given item if it is |
168 | 168 |
/// already stored in the heap. Otherwise it inserts the given |
169 | 169 |
/// item into the heap with the given priority. |
170 | 170 |
/// |
171 | 171 |
/// \param i The item. |
172 | 172 |
/// \param p The priority. |
173 | 173 |
void set(const Item &i, const Prio &p) {} |
174 | 174 |
|
175 | 175 |
/// \brief Decrease the priority of an item to the given value. |
176 | 176 |
/// |
177 | 177 |
/// This function decreases the priority of an item to the given value. |
178 | 178 |
/// \param i The item. |
179 | 179 |
/// \param p The priority. |
180 | 180 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
181 | 181 |
void decrease(const Item &i, const Prio &p) {} |
182 | 182 |
|
183 | 183 |
/// \brief Increase the priority of an item to the given value. |
184 | 184 |
/// |
185 | 185 |
/// This function increases the priority of an item to the given value. |
186 | 186 |
/// \param i The item. |
187 | 187 |
/// \param p The priority. |
188 | 188 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
189 | 189 |
void increase(const Item &i, const Prio &p) {} |
190 | 190 |
|
191 | 191 |
/// \brief Return the state of an item. |
192 | 192 |
/// |
193 | 193 |
/// This method returns \c PRE_HEAP if the given item has never |
194 | 194 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
195 | 195 |
/// and \c POST_HEAP otherwise. |
196 | 196 |
/// In the latter case it is possible that the item will get back |
197 | 197 |
/// to the heap again. |
198 | 198 |
/// \param i The item. |
199 | 199 |
State state(const Item &i) const {} |
200 | 200 |
|
201 | 201 |
/// \brief Set the state of an item in the heap. |
202 | 202 |
/// |
203 | 203 |
/// This function sets the state of the given item in the heap. |
204 | 204 |
/// It can be used to manually clear the heap when it is important |
205 | 205 |
/// to achive better time complexity. |
206 | 206 |
/// \param i The item. |
207 | 207 |
/// \param st The state. It should not be \c IN_HEAP. |
208 | 208 |
void state(const Item& i, State st) {} |
209 | 209 |
|
210 | 210 |
|
211 | 211 |
template <typename _Heap> |
212 | 212 |
struct Constraints { |
213 | 213 |
public: |
214 | 214 |
void constraints() { |
215 | 215 |
typedef typename _Heap::Item OwnItem; |
216 | 216 |
typedef typename _Heap::Prio OwnPrio; |
217 | 217 |
typedef typename _Heap::State OwnState; |
218 | 218 |
|
219 | 219 |
Item item; |
220 | 220 |
Prio prio; |
221 | 221 |
item=Item(); |
222 | 222 |
prio=Prio(); |
223 | 223 |
ignore_unused_variable_warning(item); |
224 | 224 |
ignore_unused_variable_warning(prio); |
225 | 225 |
|
226 | 226 |
OwnItem own_item; |
227 | 227 |
OwnPrio own_prio; |
228 | 228 |
OwnState own_state; |
229 | 229 |
own_item=Item(); |
230 | 230 |
own_prio=Prio(); |
231 | 231 |
ignore_unused_variable_warning(own_item); |
232 | 232 |
ignore_unused_variable_warning(own_prio); |
233 | 233 |
ignore_unused_variable_warning(own_state); |
234 | 234 |
|
235 | 235 |
_Heap heap1(map); |
236 | 236 |
_Heap heap2 = heap1; |
237 | 237 |
ignore_unused_variable_warning(heap1); |
238 | 238 |
ignore_unused_variable_warning(heap2); |
239 | 239 |
|
240 | 240 |
int s = heap.size(); |
241 | 241 |
ignore_unused_variable_warning(s); |
242 | 242 |
bool e = heap.empty(); |
243 | 243 |
ignore_unused_variable_warning(e); |
244 | 244 |
|
245 | 245 |
prio = heap.prio(); |
246 | 246 |
item = heap.top(); |
247 | 247 |
prio = heap[item]; |
248 | 248 |
own_prio = heap.prio(); |
249 | 249 |
own_item = heap.top(); |
250 | 250 |
own_prio = heap[own_item]; |
251 | 251 |
|
252 | 252 |
heap.push(item, prio); |
253 | 253 |
heap.push(own_item, own_prio); |
254 | 254 |
heap.pop(); |
255 | 255 |
|
256 | 256 |
heap.set(item, prio); |
257 | 257 |
heap.decrease(item, prio); |
258 | 258 |
heap.increase(item, prio); |
259 | 259 |
heap.set(own_item, own_prio); |
260 | 260 |
heap.decrease(own_item, own_prio); |
261 | 261 |
heap.increase(own_item, own_prio); |
262 | 262 |
|
263 | 263 |
heap.erase(item); |
264 | 264 |
heap.erase(own_item); |
265 | 265 |
heap.clear(); |
266 | 266 |
|
267 | 267 |
own_state = heap.state(own_item); |
268 | 268 |
heap.state(own_item, own_state); |
269 | 269 |
|
270 | 270 |
own_state = _Heap::PRE_HEAP; |
271 | 271 |
own_state = _Heap::IN_HEAP; |
272 | 272 |
own_state = _Heap::POST_HEAP; |
273 | 273 |
} |
274 | 274 |
|
275 | 275 |
_Heap& heap; |
276 | 276 |
ItemIntMap& map; |
277 | 277 |
}; |
278 | 278 |
}; |
279 | 279 |
|
280 | 280 |
/// @} |
281 | 281 |
} // namespace lemon |
282 | 282 |
} |
283 | 283 |
#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_FIB_HEAP_H |
20 | 20 |
#define LEMON_FIB_HEAP_H |
21 | 21 |
|
22 | 22 |
///\file |
23 |
///\ingroup |
|
23 |
///\ingroup heaps |
|
24 | 24 |
///\brief Fibonacci heap implementation. |
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <utility> |
28 | 28 |
#include <functional> |
29 | 29 |
#include <lemon/math.h> |
30 | 30 |
|
31 | 31 |
namespace lemon { |
32 | 32 |
|
33 |
/// \ingroup |
|
33 |
/// \ingroup heaps |
|
34 | 34 |
/// |
35 | 35 |
/// \brief Fibonacci heap data structure. |
36 | 36 |
/// |
37 | 37 |
/// This class implements the \e Fibonacci \e heap data structure. |
38 | 38 |
/// It fully conforms to the \ref concepts::Heap "heap concept". |
39 | 39 |
/// |
40 | 40 |
/// The methods \ref increase() and \ref erase() are not efficient in a |
41 | 41 |
/// Fibonacci heap. In case of many calls of these operations, it is |
42 | 42 |
/// better to use other heap structure, e.g. \ref BinHeap "binary heap". |
43 | 43 |
/// |
44 | 44 |
/// \tparam PR Type of the priorities of the items. |
45 | 45 |
/// \tparam IM A read-writable item map with \c int values, used |
46 | 46 |
/// internally to handle the cross references. |
47 | 47 |
/// \tparam CMP A functor class for comparing the priorities. |
48 | 48 |
/// The default is \c std::less<PR>. |
49 | 49 |
#ifdef DOXYGEN |
50 | 50 |
template <typename PR, typename IM, typename CMP> |
51 | 51 |
#else |
52 | 52 |
template <typename PR, typename IM, typename CMP = std::less<PR> > |
53 | 53 |
#endif |
54 | 54 |
class FibHeap { |
55 | 55 |
public: |
56 | 56 |
|
57 | 57 |
/// Type of the item-int map. |
58 | 58 |
typedef IM ItemIntMap; |
59 | 59 |
/// Type of the priorities. |
60 | 60 |
typedef PR Prio; |
61 | 61 |
/// Type of the items stored in the heap. |
62 | 62 |
typedef typename ItemIntMap::Key Item; |
63 | 63 |
/// Type of the item-priority pairs. |
64 | 64 |
typedef std::pair<Item,Prio> Pair; |
65 | 65 |
/// Functor type for comparing the priorities. |
66 | 66 |
typedef CMP Compare; |
67 | 67 |
|
68 | 68 |
private: |
69 | 69 |
class Store; |
70 | 70 |
|
71 | 71 |
std::vector<Store> _data; |
72 | 72 |
int _minimum; |
73 | 73 |
ItemIntMap &_iim; |
74 | 74 |
Compare _comp; |
75 | 75 |
int _num; |
76 | 76 |
|
77 | 77 |
public: |
78 | 78 |
|
79 | 79 |
/// \brief Type to represent the states of the items. |
80 | 80 |
/// |
81 | 81 |
/// Each item has a state associated to it. It can be "in heap", |
82 | 82 |
/// "pre-heap" or "post-heap". The latter two are indifferent from the |
83 | 83 |
/// heap's point of view, but may be useful to the user. |
84 | 84 |
/// |
85 | 85 |
/// The item-int map must be initialized in such way that it assigns |
86 | 86 |
/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
87 | 87 |
enum State { |
88 | 88 |
IN_HEAP = 0, ///< = 0. |
89 | 89 |
PRE_HEAP = -1, ///< = -1. |
90 | 90 |
POST_HEAP = -2 ///< = -2. |
91 | 91 |
}; |
92 | 92 |
|
93 | 93 |
/// \brief Constructor. |
94 | 94 |
/// |
95 | 95 |
/// Constructor. |
96 | 96 |
/// \param map A map that assigns \c int values to the items. |
97 | 97 |
/// It is used internally to handle the cross references. |
98 | 98 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
99 | 99 |
explicit FibHeap(ItemIntMap &map) |
100 | 100 |
: _minimum(0), _iim(map), _num() {} |
101 | 101 |
|
102 | 102 |
/// \brief Constructor. |
103 | 103 |
/// |
104 | 104 |
/// Constructor. |
105 | 105 |
/// \param map A map that assigns \c int values to the items. |
106 | 106 |
/// It is used internally to handle the cross references. |
107 | 107 |
/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
108 | 108 |
/// \param comp The function object used for comparing the priorities. |
109 | 109 |
FibHeap(ItemIntMap &map, const Compare &comp) |
110 | 110 |
: _minimum(0), _iim(map), _comp(comp), _num() {} |
111 | 111 |
|
112 | 112 |
/// \brief The number of items stored in the heap. |
113 | 113 |
/// |
114 | 114 |
/// This function returns the number of items stored in the heap. |
115 | 115 |
int size() const { return _num; } |
116 | 116 |
|
117 | 117 |
/// \brief Check if the heap is empty. |
118 | 118 |
/// |
119 | 119 |
/// This function returns \c true if the heap is empty. |
120 | 120 |
bool empty() const { return _num==0; } |
121 | 121 |
|
122 | 122 |
/// \brief Make the heap empty. |
123 | 123 |
/// |
124 | 124 |
/// This functon makes the heap empty. |
125 | 125 |
/// It does not change the cross reference map. If you want to reuse |
126 | 126 |
/// a heap that is not surely empty, you should first clear it and |
127 | 127 |
/// then you should set the cross reference map to \c PRE_HEAP |
128 | 128 |
/// for each item. |
129 | 129 |
void clear() { |
130 | 130 |
_data.clear(); _minimum = 0; _num = 0; |
131 | 131 |
} |
132 | 132 |
|
133 | 133 |
/// \brief Insert an item into the heap with the given priority. |
134 | 134 |
/// |
135 | 135 |
/// This function inserts the given item into the heap with the |
136 | 136 |
/// given priority. |
137 | 137 |
/// \param item The item to insert. |
138 | 138 |
/// \param prio The priority of the item. |
139 | 139 |
/// \pre \e item must not be stored in the heap. |
140 | 140 |
void push (const Item& item, const Prio& prio) { |
141 | 141 |
int i=_iim[item]; |
142 | 142 |
if ( i < 0 ) { |
143 | 143 |
int s=_data.size(); |
144 | 144 |
_iim.set( item, s ); |
145 | 145 |
Store st; |
146 | 146 |
st.name=item; |
147 | 147 |
_data.push_back(st); |
148 | 148 |
i=s; |
149 | 149 |
} else { |
150 | 150 |
_data[i].parent=_data[i].child=-1; |
151 | 151 |
_data[i].degree=0; |
152 | 152 |
_data[i].in=true; |
153 | 153 |
_data[i].marked=false; |
154 | 154 |
} |
155 | 155 |
|
156 | 156 |
if ( _num ) { |
157 | 157 |
_data[_data[_minimum].right_neighbor].left_neighbor=i; |
158 | 158 |
_data[i].right_neighbor=_data[_minimum].right_neighbor; |
159 | 159 |
_data[_minimum].right_neighbor=i; |
160 | 160 |
_data[i].left_neighbor=_minimum; |
161 | 161 |
if ( _comp( prio, _data[_minimum].prio) ) _minimum=i; |
162 | 162 |
} else { |
163 | 163 |
_data[i].right_neighbor=_data[i].left_neighbor=i; |
164 | 164 |
_minimum=i; |
165 | 165 |
} |
166 | 166 |
_data[i].prio=prio; |
167 | 167 |
++_num; |
168 | 168 |
} |
169 | 169 |
|
170 | 170 |
/// \brief Return the item having minimum priority. |
171 | 171 |
/// |
172 | 172 |
/// This function returns the item having minimum priority. |
173 | 173 |
/// \pre The heap must be non-empty. |
174 | 174 |
Item top() const { return _data[_minimum].name; } |
175 | 175 |
|
176 | 176 |
/// \brief The minimum priority. |
177 | 177 |
/// |
178 | 178 |
/// This function returns the minimum priority. |
179 | 179 |
/// \pre The heap must be non-empty. |
180 | 180 |
Prio prio() const { return _data[_minimum].prio; } |
181 | 181 |
|
182 | 182 |
/// \brief Remove the item having minimum priority. |
183 | 183 |
/// |
184 | 184 |
/// This function removes the item having minimum priority. |
185 | 185 |
/// \pre The heap must be non-empty. |
186 | 186 |
void pop() { |
187 | 187 |
/*The first case is that there are only one root.*/ |
188 | 188 |
if ( _data[_minimum].left_neighbor==_minimum ) { |
189 | 189 |
_data[_minimum].in=false; |
190 | 190 |
if ( _data[_minimum].degree!=0 ) { |
191 | 191 |
makeroot(_data[_minimum].child); |
192 | 192 |
_minimum=_data[_minimum].child; |
193 | 193 |
balance(); |
194 | 194 |
} |
195 | 195 |
} else { |
196 | 196 |
int right=_data[_minimum].right_neighbor; |
197 | 197 |
unlace(_minimum); |
198 | 198 |
_data[_minimum].in=false; |
199 | 199 |
if ( _data[_minimum].degree > 0 ) { |
200 | 200 |
int left=_data[_minimum].left_neighbor; |
201 | 201 |
int child=_data[_minimum].child; |
202 | 202 |
int last_child=_data[child].left_neighbor; |
203 | 203 |
|
204 | 204 |
makeroot(child); |
205 | 205 |
|
206 | 206 |
_data[left].right_neighbor=child; |
207 | 207 |
_data[child].left_neighbor=left; |
208 | 208 |
_data[right].left_neighbor=last_child; |
209 | 209 |
_data[last_child].right_neighbor=right; |
210 | 210 |
} |
211 | 211 |
_minimum=right; |
212 | 212 |
balance(); |
213 | 213 |
} // the case where there are more roots |
214 | 214 |
--_num; |
215 | 215 |
} |
216 | 216 |
|
217 | 217 |
/// \brief Remove the given item from the heap. |
218 | 218 |
/// |
219 | 219 |
/// This function removes the given item from the heap if it is |
220 | 220 |
/// already stored. |
221 | 221 |
/// \param item The item to delete. |
222 | 222 |
/// \pre \e item must be in the heap. |
223 | 223 |
void erase (const Item& item) { |
224 | 224 |
int i=_iim[item]; |
225 | 225 |
|
226 | 226 |
if ( i >= 0 && _data[i].in ) { |
227 | 227 |
if ( _data[i].parent!=-1 ) { |
228 | 228 |
int p=_data[i].parent; |
229 | 229 |
cut(i,p); |
230 | 230 |
cascade(p); |
231 | 231 |
} |
232 | 232 |
_minimum=i; //As if its prio would be -infinity |
233 | 233 |
pop(); |
234 | 234 |
} |
235 | 235 |
} |
236 | 236 |
|
237 | 237 |
/// \brief The priority of the given item. |
238 | 238 |
/// |
239 | 239 |
/// This function returns the priority of the given item. |
240 | 240 |
/// \param item The item. |
241 | 241 |
/// \pre \e item must be in the heap. |
242 | 242 |
Prio operator[](const Item& item) const { |
243 | 243 |
return _data[_iim[item]].prio; |
244 | 244 |
} |
245 | 245 |
|
246 | 246 |
/// \brief Set the priority of an item or insert it, if it is |
247 | 247 |
/// not stored in the heap. |
248 | 248 |
/// |
249 | 249 |
/// This method sets the priority of the given item if it is |
250 | 250 |
/// already stored in the heap. Otherwise it inserts the given |
251 | 251 |
/// item into the heap with the given priority. |
252 | 252 |
/// \param item The item. |
253 | 253 |
/// \param prio The priority. |
254 | 254 |
void set (const Item& item, const Prio& prio) { |
255 | 255 |
int i=_iim[item]; |
256 | 256 |
if ( i >= 0 && _data[i].in ) { |
257 | 257 |
if ( _comp(prio, _data[i].prio) ) decrease(item, prio); |
258 | 258 |
if ( _comp(_data[i].prio, prio) ) increase(item, prio); |
259 | 259 |
} else push(item, prio); |
260 | 260 |
} |
261 | 261 |
|
262 | 262 |
/// \brief Decrease the priority of an item to the given value. |
263 | 263 |
/// |
264 | 264 |
/// This function decreases the priority of an item to the given value. |
265 | 265 |
/// \param item The item. |
266 | 266 |
/// \param prio The priority. |
267 | 267 |
/// \pre \e item must be stored in the heap with priority at least \e prio. |
268 | 268 |
void decrease (const Item& item, const Prio& prio) { |
269 | 269 |
int i=_iim[item]; |
270 | 270 |
_data[i].prio=prio; |
271 | 271 |
int p=_data[i].parent; |
272 | 272 |
|
273 | 273 |
if ( p!=-1 && _comp(prio, _data[p].prio) ) { |
274 | 274 |
cut(i,p); |
275 | 275 |
cascade(p); |
276 | 276 |
} |
277 | 277 |
if ( _comp(prio, _data[_minimum].prio) ) _minimum=i; |
278 | 278 |
} |
279 | 279 |
|
280 | 280 |
/// \brief Increase the priority of an item to the given value. |
281 | 281 |
/// |
282 | 282 |
/// This function increases the priority of an item to the given value. |
283 | 283 |
/// \param item The item. |
284 | 284 |
/// \param prio The priority. |
285 | 285 |
/// \pre \e item must be stored in the heap with priority at most \e prio. |
286 | 286 |
void increase (const Item& item, const Prio& prio) { |
287 | 287 |
erase(item); |
288 | 288 |
push(item, prio); |
289 | 289 |
} |
290 | 290 |
|
291 | 291 |
/// \brief Return the state of an item. |
292 | 292 |
/// |
293 | 293 |
/// This method returns \c PRE_HEAP if the given item has never |
294 | 294 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
295 | 295 |
/// and \c POST_HEAP otherwise. |
296 | 296 |
/// In the latter case it is possible that the item will get back |
297 | 297 |
/// to the heap again. |
298 | 298 |
/// \param item The item. |
299 | 299 |
State state(const Item &item) const { |
300 | 300 |
int i=_iim[item]; |
301 | 301 |
if( i>=0 ) { |
302 | 302 |
if ( _data[i].in ) i=0; |
303 | 303 |
else i=-2; |
304 | 304 |
} |
305 | 305 |
return State(i); |
306 | 306 |
} |
307 | 307 |
|
308 | 308 |
/// \brief Set the state of an item in the heap. |
309 | 309 |
/// |
310 | 310 |
/// This function sets the state of the given item in the heap. |
311 | 311 |
/// It can be used to manually clear the heap when it is important |
312 | 312 |
/// to achive better time complexity. |
313 | 313 |
/// \param i The item. |
314 | 314 |
/// \param st The state. It should not be \c IN_HEAP. |
315 | 315 |
void state(const Item& i, State st) { |
316 | 316 |
switch (st) { |
317 | 317 |
case POST_HEAP: |
318 | 318 |
case PRE_HEAP: |
319 | 319 |
if (state(i) == IN_HEAP) { |
320 | 320 |
erase(i); |
321 | 321 |
} |
322 | 322 |
_iim[i] = st; |
323 | 323 |
break; |
324 | 324 |
case IN_HEAP: |
325 | 325 |
break; |
326 | 326 |
} |
327 | 327 |
} |
328 | 328 |
|
329 | 329 |
private: |
330 | 330 |
|
331 | 331 |
void balance() { |
332 | 332 |
|
333 | 333 |
int maxdeg=int( std::floor( 2.08*log(double(_data.size()))))+1; |
334 | 334 |
|
335 | 335 |
std::vector<int> A(maxdeg,-1); |
336 | 336 |
|
337 | 337 |
/* |
338 | 338 |
*Recall that now minimum does not point to the minimum prio element. |
339 | 339 |
*We set minimum to this during balance(). |
340 | 340 |
*/ |
341 | 341 |
int anchor=_data[_minimum].left_neighbor; |
342 | 342 |
int next=_minimum; |
343 | 343 |
bool end=false; |
344 | 344 |
|
345 | 345 |
do { |
346 | 346 |
int active=next; |
347 | 347 |
if ( anchor==active ) end=true; |
348 | 348 |
int d=_data[active].degree; |
349 | 349 |
next=_data[active].right_neighbor; |
350 | 350 |
|
351 | 351 |
while (A[d]!=-1) { |
352 | 352 |
if( _comp(_data[active].prio, _data[A[d]].prio) ) { |
353 | 353 |
fuse(active,A[d]); |
354 | 354 |
} else { |
355 | 355 |
fuse(A[d],active); |
356 | 356 |
active=A[d]; |
357 | 357 |
} |
358 | 358 |
A[d]=-1; |
359 | 359 |
++d; |
360 | 360 |
} |
361 | 361 |
A[d]=active; |
362 | 362 |
} while ( !end ); |
363 | 363 |
|
364 | 364 |
|
365 | 365 |
while ( _data[_minimum].parent >=0 ) |
366 | 366 |
_minimum=_data[_minimum].parent; |
367 | 367 |
int s=_minimum; |
368 | 368 |
int m=_minimum; |
369 | 369 |
do { |
370 | 370 |
if ( _comp(_data[s].prio, _data[_minimum].prio) ) _minimum=s; |
371 | 371 |
s=_data[s].right_neighbor; |
372 | 372 |
} while ( s != m ); |
373 | 373 |
} |
374 | 374 |
|
375 | 375 |
void makeroot(int c) { |
376 | 376 |
int s=c; |
377 | 377 |
do { |
378 | 378 |
_data[s].parent=-1; |
379 | 379 |
s=_data[s].right_neighbor; |
380 | 380 |
} while ( s != c ); |
381 | 381 |
} |
382 | 382 |
|
383 | 383 |
void cut(int a, int b) { |
384 | 384 |
/* |
385 | 385 |
*Replacing a from the children of b. |
386 | 386 |
*/ |
387 | 387 |
--_data[b].degree; |
388 | 388 |
|
389 | 389 |
if ( _data[b].degree !=0 ) { |
390 | 390 |
int child=_data[b].child; |
391 | 391 |
if ( child==a ) |
392 | 392 |
_data[b].child=_data[child].right_neighbor; |
393 | 393 |
unlace(a); |
394 | 394 |
} |
395 | 395 |
|
396 | 396 |
|
397 | 397 |
/*Lacing a to the roots.*/ |
398 | 398 |
int right=_data[_minimum].right_neighbor; |
399 | 399 |
_data[_minimum].right_neighbor=a; |
400 | 400 |
_data[a].left_neighbor=_minimum; |
401 | 401 |
_data[a].right_neighbor=right; |
402 | 402 |
_data[right].left_neighbor=a; |
403 | 403 |
|
404 | 404 |
_data[a].parent=-1; |
405 | 405 |
_data[a].marked=false; |
406 | 406 |
} |
407 | 407 |
|
408 | 408 |
void cascade(int a) { |
409 | 409 |
if ( _data[a].parent!=-1 ) { |
410 | 410 |
int p=_data[a].parent; |
411 | 411 |
|
412 | 412 |
if ( _data[a].marked==false ) _data[a].marked=true; |
413 | 413 |
else { |
414 | 414 |
cut(a,p); |
415 | 415 |
cascade(p); |
416 | 416 |
} |
417 | 417 |
} |
418 | 418 |
} |
419 | 419 |
|
420 | 420 |
void fuse(int a, int b) { |
421 | 421 |
unlace(b); |
422 | 422 |
|
423 | 423 |
/*Lacing b under a.*/ |
424 | 424 |
_data[b].parent=a; |
425 | 425 |
|
426 | 426 |
if (_data[a].degree==0) { |
427 | 427 |
_data[b].left_neighbor=b; |
428 | 428 |
_data[b].right_neighbor=b; |
429 | 429 |
_data[a].child=b; |
430 | 430 |
} else { |
431 | 431 |
int child=_data[a].child; |
432 | 432 |
int last_child=_data[child].left_neighbor; |
433 | 433 |
_data[child].left_neighbor=b; |
434 | 434 |
_data[b].right_neighbor=child; |
435 | 435 |
_data[last_child].right_neighbor=b; |
436 | 436 |
_data[b].left_neighbor=last_child; |
437 | 437 |
} |
438 | 438 |
|
439 | 439 |
++_data[a].degree; |
440 | 440 |
|
441 | 441 |
_data[b].marked=false; |
442 | 442 |
} |
443 | 443 |
|
444 | 444 |
/* |
445 | 445 |
*It is invoked only if a has siblings. |
446 | 446 |
*/ |
447 | 447 |
void unlace(int a) { |
448 | 448 |
int leftn=_data[a].left_neighbor; |
449 | 449 |
int rightn=_data[a].right_neighbor; |
450 | 450 |
_data[leftn].right_neighbor=rightn; |
451 | 451 |
_data[rightn].left_neighbor=leftn; |
452 | 452 |
} |
453 | 453 |
|
454 | 454 |
|
455 | 455 |
class Store { |
456 | 456 |
friend class FibHeap; |
457 | 457 |
|
458 | 458 |
Item name; |
459 | 459 |
int parent; |
460 | 460 |
int left_neighbor; |
461 | 461 |
int right_neighbor; |
462 | 462 |
int child; |
463 | 463 |
int degree; |
464 | 464 |
bool marked; |
465 | 465 |
bool in; |
466 | 466 |
Prio prio; |
467 | 467 |
|
468 | 468 |
Store() : parent(-1), child(-1), degree(), marked(false), in(true) {} |
469 | 469 |
}; |
470 | 470 |
}; |
471 | 471 |
|
472 | 472 |
} //namespace lemon |
473 | 473 |
|
474 | 474 |
#endif //LEMON_FIB_HEAP_H |
475 | 475 |
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_RADIX_HEAP_H |
20 | 20 |
#define LEMON_RADIX_HEAP_H |
21 | 21 |
|
22 |
///\ingroup |
|
22 |
///\ingroup heaps |
|
23 | 23 |
///\file |
24 | 24 |
///\brief Radix heap implementation. |
25 | 25 |
|
26 | 26 |
#include <vector> |
27 | 27 |
#include <lemon/error.h> |
28 | 28 |
|
29 | 29 |
namespace lemon { |
30 | 30 |
|
31 | 31 |
|
32 |
/// \ingroup |
|
32 |
/// \ingroup heaps |
|
33 | 33 |
/// |
34 | 34 |
/// \brief Radix heap data structure. |
35 | 35 |
/// |
36 | 36 |
/// This class implements the \e radix \e heap data structure. |
37 | 37 |
/// It practically conforms to the \ref concepts::Heap "heap concept", |
38 | 38 |
/// but it has some limitations due its special implementation. |
39 | 39 |
/// The type of the priorities must be \c int and the priority of an |
40 | 40 |
/// item cannot be decreased under the priority of the last removed item. |
41 | 41 |
/// |
42 | 42 |
/// \tparam IM A read-writable item map with \c int values, used |
43 | 43 |
/// internally to handle the cross references. |
44 | 44 |
template <typename IM> |
45 | 45 |
class RadixHeap { |
46 | 46 |
|
47 | 47 |
public: |
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|
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/// Type of the item-int map. |
50 | 50 |
typedef IM ItemIntMap; |
51 | 51 |
/// Type of the priorities. |
52 | 52 |
typedef int Prio; |
53 | 53 |
/// Type of the items stored in the heap. |
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typedef typename ItemIntMap::Key Item; |
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|
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/// \brief Exception thrown by RadixHeap. |
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/// |
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/// This exception is thrown when an item is inserted into a |
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/// RadixHeap with a priority smaller than the last erased one. |
60 | 60 |
/// \see RadixHeap |
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class UnderFlowPriorityError : public Exception { |
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public: |
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virtual const char* what() const throw() { |
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return "lemon::RadixHeap::UnderFlowPriorityError"; |
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} |
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}; |
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|
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/// \brief Type to represent the states of the items. |
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/// |
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/// Each item has a state associated to it. It can be "in heap", |
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/// "pre-heap" or "post-heap". The latter two are indifferent from the |
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/// heap's point of view, but may be useful to the user. |
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/// |
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/// The item-int map must be initialized in such way that it assigns |
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/// \c PRE_HEAP (<tt>-1</tt>) to any element to be put in the heap. |
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enum State { |
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IN_HEAP = 0, ///< = 0. |
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PRE_HEAP = -1, ///< = -1. |
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POST_HEAP = -2 ///< = -2. |
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}; |
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|
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private: |
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|
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struct RadixItem { |
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int prev, next, box; |
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Item item; |
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int prio; |
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RadixItem(Item _item, int _prio) : item(_item), prio(_prio) {} |
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}; |
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|
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struct RadixBox { |
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int first; |
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int min, size; |
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RadixBox(int _min, int _size) : first(-1), min(_min), size(_size) {} |
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}; |
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|
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std::vector<RadixItem> data; |
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std::vector<RadixBox> boxes; |
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|
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ItemIntMap &_iim; |
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|
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public: |
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|
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/// \brief Constructor. |
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/// |
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/// Constructor. |
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/// \param map A map that assigns \c int values to the items. |
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/// It is used internally to handle the cross references. |
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/// The assigned value must be \c PRE_HEAP (<tt>-1</tt>) for each item. |
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/// \param minimum The initial minimum value of the heap. |
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/// \param capacity The initial capacity of the heap. |
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RadixHeap(ItemIntMap &map, int minimum = 0, int capacity = 0) |
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: _iim(map) |
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{ |
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boxes.push_back(RadixBox(minimum, 1)); |
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boxes.push_back(RadixBox(minimum + 1, 1)); |
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while (lower(boxes.size() - 1, capacity + minimum - 1)) { |
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extend(); |
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} |
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} |
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|
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/// \brief The number of items stored in the heap. |
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/// |
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/// This function returns the number of items stored in the heap. |
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int size() const { return data.size(); } |
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|
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/// \brief Check if the heap is empty. |
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/// |
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/// This function returns \c true if the heap is empty. |
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bool empty() const { return data.empty(); } |
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|
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/// \brief Make the heap empty. |
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/// |
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/// This functon makes the heap empty. |
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/// It does not change the cross reference map. If you want to reuse |
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/// a heap that is not surely empty, you should first clear it and |
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/// then you should set the cross reference map to \c PRE_HEAP |
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/// for each item. |
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/// \param minimum The minimum value of the heap. |
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/// \param capacity The capacity of the heap. |
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void clear(int minimum = 0, int capacity = 0) { |
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data.clear(); boxes.clear(); |
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boxes.push_back(RadixBox(minimum, 1)); |
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boxes.push_back(RadixBox(minimum + 1, 1)); |
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while (lower(boxes.size() - 1, capacity + minimum - 1)) { |
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extend(); |
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} |
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} |
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|
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private: |
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|
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bool upper(int box, Prio pr) { |
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return pr < boxes[box].min; |
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} |
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|
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bool lower(int box, Prio pr) { |
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return pr >= boxes[box].min + boxes[box].size; |
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} |
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|
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// Remove item from the box list |
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void remove(int index) { |
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if (data[index].prev >= 0) { |
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data[data[index].prev].next = data[index].next; |
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} else { |
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boxes[data[index].box].first = data[index].next; |
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} |
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if (data[index].next >= 0) { |
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data[data[index].next].prev = data[index].prev; |
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} |
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} |
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|
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// Insert item into the box list |
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void insert(int box, int index) { |
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if (boxes[box].first == -1) { |
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boxes[box].first = index; |
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data[index].next = data[index].prev = -1; |
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} else { |
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data[index].next = boxes[box].first; |
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data[boxes[box].first].prev = index; |
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data[index].prev = -1; |
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boxes[box].first = index; |
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} |
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data[index].box = box; |
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} |
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|
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// Add a new box to the box list |
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void extend() { |
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int min = boxes.back().min + boxes.back().size; |
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int bs = 2 * boxes.back().size; |
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boxes.push_back(RadixBox(min, bs)); |
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} |
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|
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// Move an item up into the proper box. |
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void bubble_up(int index) { |
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if (!lower(data[index].box, data[index].prio)) return; |
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remove(index); |
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int box = findUp(data[index].box, data[index].prio); |
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insert(box, index); |
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} |
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|
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// Find up the proper box for the item with the given priority |
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int findUp(int start, int pr) { |
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while (lower(start, pr)) { |
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if (++start == int(boxes.size())) { |
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extend(); |
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} |
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} |
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return start; |
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} |
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|
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// Move an item down into the proper box |
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void bubble_down(int index) { |
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if (!upper(data[index].box, data[index].prio)) return; |
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remove(index); |
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int box = findDown(data[index].box, data[index].prio); |
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insert(box, index); |
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} |
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|
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// Find down the proper box for the item with the given priority |
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int findDown(int start, int pr) { |
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while (upper(start, pr)) { |
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if (--start < 0) throw UnderFlowPriorityError(); |
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} |
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return start; |
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} |
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|
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// Find the first non-empty box |
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int findFirst() { |
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int first = 0; |
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while (boxes[first].first == -1) ++first; |
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return first; |
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} |
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|
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// Gives back the minimum priority of the given box |
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int minValue(int box) { |
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int min = data[boxes[box].first].prio; |
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for (int k = boxes[box].first; k != -1; k = data[k].next) { |
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if (data[k].prio < min) min = data[k].prio; |
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} |
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return min; |
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} |
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|
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// Rearrange the items of the heap and make the first box non-empty |
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void moveDown() { |
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int box = findFirst(); |
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if (box == 0) return; |
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int min = minValue(box); |
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for (int i = 0; i <= box; ++i) { |
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boxes[i].min = min; |
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min += boxes[i].size; |
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} |
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int curr = boxes[box].first, next; |
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while (curr != -1) { |
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next = data[curr].next; |
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bubble_down(curr); |
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curr = next; |
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} |
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} |
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|
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void relocate_last(int index) { |
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if (index != int(data.size()) - 1) { |
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data[index] = data.back(); |
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if (data[index].prev != -1) { |
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data[data[index].prev].next = index; |
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} else { |
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boxes[data[index].box].first = index; |
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} |
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if (data[index].next != -1) { |
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data[data[index].next].prev = index; |
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} |
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_iim[data[index].item] = index; |
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} |
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data.pop_back(); |
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} |
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|
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public: |
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|
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/// \brief Insert an item into the heap with the given priority. |
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/// |
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/// This function inserts the given item into the heap with the |
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/// given priority. |
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/// \param i The item to insert. |
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/// \param p The priority of the item. |
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/// \pre \e i must not be stored in the heap. |
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/// \warning This method may throw an \c UnderFlowPriorityException. |
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void push(const Item &i, const Prio &p) { |
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int n = data.size(); |
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_iim.set(i, n); |
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data.push_back(RadixItem(i, p)); |
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while (lower(boxes.size() - 1, p)) { |
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extend(); |
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} |
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int box = findDown(boxes.size() - 1, p); |
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insert(box, n); |
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} |
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|
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/// \brief Return the item having minimum priority. |
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/// |
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/// This function returns the item having minimum priority. |
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/// \pre The heap must be non-empty. |
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Item top() const { |
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const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown(); |
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return data[boxes[0].first].item; |
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} |
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|
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/// \brief The minimum priority. |
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/// |
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/// This function returns the minimum priority. |
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/// \pre The heap must be non-empty. |
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Prio prio() const { |
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const_cast<RadixHeap<ItemIntMap>&>(*this).moveDown(); |
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return data[boxes[0].first].prio; |
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} |
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|
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/// \brief Remove the item having minimum priority. |
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/// |
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/// This function removes the item having minimum priority. |
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/// \pre The heap must be non-empty. |
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void pop() { |
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moveDown(); |
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int index = boxes[0].first; |
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_iim[data[index].item] = POST_HEAP; |
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remove(index); |
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relocate_last(index); |
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} |
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|
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/// \brief Remove the given item from the heap. |
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/// |
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/// This function removes the given item from the heap if it is |
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/// already stored. |
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/// \param i The item to delete. |
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/// \pre \e i must be in the heap. |
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void erase(const Item &i) { |
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int index = _iim[i]; |
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_iim[i] = POST_HEAP; |
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remove(index); |
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relocate_last(index); |
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} |
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|
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/// \brief The priority of the given item. |
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/// |
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/// This function returns the priority of the given item. |
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/// \param i The item. |
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/// \pre \e i must be in the heap. |
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Prio operator[](const Item &i) const { |
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int idx = _iim[i]; |
347 | 347 |
return data[idx].prio; |
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} |
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|
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/// \brief Set the priority of an item or insert it, if it is |
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/// not stored in the heap. |
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/// |
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/// This method sets the priority of the given item if it is |
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/// already stored in the heap. Otherwise it inserts the given |
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/// item into the heap with the given priority. |
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/// \param i The item. |
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/// \param p The priority. |
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/// \pre \e i must be in the heap. |
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/// \warning This method may throw an \c UnderFlowPriorityException. |
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void set(const Item &i, const Prio &p) { |
361 | 361 |
int idx = _iim[i]; |
362 | 362 |
if( idx < 0 ) { |
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push(i, p); |
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} |
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else if( p >= data[idx].prio ) { |
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data[idx].prio = p; |
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bubble_up(idx); |
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} else { |
369 | 369 |
data[idx].prio = p; |
370 | 370 |
bubble_down(idx); |
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} |
372 | 372 |
} |
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|
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/// \brief Decrease the priority of an item to the given value. |
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/// |
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/// This function decreases the priority of an item to the given value. |
377 | 377 |
/// \param i The item. |
378 | 378 |
/// \param p The priority. |
379 | 379 |
/// \pre \e i must be stored in the heap with priority at least \e p. |
380 | 380 |
/// \warning This method may throw an \c UnderFlowPriorityException. |
381 | 381 |
void decrease(const Item &i, const Prio &p) { |
382 | 382 |
int idx = _iim[i]; |
383 | 383 |
data[idx].prio = p; |
384 | 384 |
bubble_down(idx); |
385 | 385 |
} |
386 | 386 |
|
387 | 387 |
/// \brief Increase the priority of an item to the given value. |
388 | 388 |
/// |
389 | 389 |
/// This function increases the priority of an item to the given value. |
390 | 390 |
/// \param i The item. |
391 | 391 |
/// \param p The priority. |
392 | 392 |
/// \pre \e i must be stored in the heap with priority at most \e p. |
393 | 393 |
void increase(const Item &i, const Prio &p) { |
394 | 394 |
int idx = _iim[i]; |
395 | 395 |
data[idx].prio = p; |
396 | 396 |
bubble_up(idx); |
397 | 397 |
} |
398 | 398 |
|
399 | 399 |
/// \brief Return the state of an item. |
400 | 400 |
/// |
401 | 401 |
/// This method returns \c PRE_HEAP if the given item has never |
402 | 402 |
/// been in the heap, \c IN_HEAP if it is in the heap at the moment, |
403 | 403 |
/// and \c POST_HEAP otherwise. |
404 | 404 |
/// In the latter case it is possible that the item will get back |
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/// to the heap again. |
406 | 406 |
/// \param i The item. |
407 | 407 |
State state(const Item &i) const { |
408 | 408 |
int s = _iim[i]; |
409 | 409 |
if( s >= 0 ) s = 0; |
410 | 410 |
return State(s); |
411 | 411 |
} |
412 | 412 |
|
413 | 413 |
/// \brief Set the state of an item in the heap. |
414 | 414 |
/// |
415 | 415 |
/// This function sets the state of the given item in the heap. |
416 | 416 |
/// It can be used to manually clear the heap when it is important |
417 | 417 |
/// to achive better time complexity. |
418 | 418 |
/// \param i The item. |
419 | 419 |
/// \param st The state. It should not be \c IN_HEAP. |
420 | 420 |
void state(const Item& i, State st) { |
421 | 421 |
switch (st) { |
422 | 422 |
case POST_HEAP: |
423 | 423 |
case PRE_HEAP: |
424 | 424 |
if (state(i) == IN_HEAP) { |
425 | 425 |
erase(i); |
426 | 426 |
} |
427 | 427 |
_iim[i] = st; |
428 | 428 |
break; |
429 | 429 |
case IN_HEAP: |
430 | 430 |
break; |
431 | 431 |
} |
432 | 432 |
} |
433 | 433 |
|
434 | 434 |
}; // class RadixHeap |
435 | 435 |
|
436 | 436 |
} // namespace lemon |
437 | 437 |
|
438 | 438 |
#endif // LEMON_RADIX_HEAP_H |
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