[906] | 1 | /* -*- C++ -*- |
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| 2 | * |
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[1956] | 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2006 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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[1359] | 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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[906] | 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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[921] | 19 | #ifndef LEMON_DFS_H |
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| 20 | #define LEMON_DFS_H |
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[780] | 21 | |
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| 22 | ///\ingroup flowalgs |
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| 23 | ///\file |
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[1218] | 24 | ///\brief Dfs algorithm. |
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[780] | 25 | |
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[1218] | 26 | #include <lemon/list_graph.h> |
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[946] | 27 | #include <lemon/graph_utils.h> |
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[1993] | 28 | #include <lemon/bits/invalid.h> |
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[1218] | 29 | #include <lemon/error.h> |
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| 30 | #include <lemon/maps.h> |
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[780] | 31 | |
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[1749] | 32 | #include <lemon/concept_check.h> |
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| 33 | |
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[921] | 34 | namespace lemon { |
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[780] | 35 | |
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[1218] | 36 | |
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| 37 | ///Default traits class of Dfs class. |
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| 38 | |
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| 39 | ///Default traits class of Dfs class. |
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| 40 | ///\param GR Graph type. |
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| 41 | template<class GR> |
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| 42 | struct DfsDefaultTraits |
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| 43 | { |
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| 44 | ///The graph type the algorithm runs on. |
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| 45 | typedef GR Graph; |
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| 46 | ///\brief The type of the map that stores the last |
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| 47 | ///edges of the %DFS paths. |
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| 48 | /// |
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| 49 | ///The type of the map that stores the last |
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| 50 | ///edges of the %DFS paths. |
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| 51 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 52 | /// |
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| 53 | typedef typename Graph::template NodeMap<typename GR::Edge> PredMap; |
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| 54 | ///Instantiates a PredMap. |
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| 55 | |
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| 56 | ///This function instantiates a \ref PredMap. |
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| 57 | ///\param G is the graph, to which we would like to define the PredMap. |
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| 58 | ///\todo The graph alone may be insufficient to initialize |
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| 59 | static PredMap *createPredMap(const GR &G) |
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| 60 | { |
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| 61 | return new PredMap(G); |
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| 62 | } |
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| 63 | |
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| 64 | ///The type of the map that indicates which nodes are processed. |
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| 65 | |
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| 66 | ///The type of the map that indicates which nodes are processed. |
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| 67 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 68 | ///\todo named parameter to set this type, function to read and write. |
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| 69 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
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| 70 | ///Instantiates a ProcessedMap. |
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| 71 | |
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| 72 | ///This function instantiates a \ref ProcessedMap. |
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[1536] | 73 | ///\param g is the graph, to which |
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[1218] | 74 | ///we would like to define the \ref ProcessedMap |
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[1536] | 75 | #ifdef DOXYGEN |
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| 76 | static ProcessedMap *createProcessedMap(const GR &g) |
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| 77 | #else |
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[1367] | 78 | static ProcessedMap *createProcessedMap(const GR &) |
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[1536] | 79 | #endif |
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[1218] | 80 | { |
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| 81 | return new ProcessedMap(); |
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| 82 | } |
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| 83 | ///The type of the map that indicates which nodes are reached. |
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| 84 | |
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| 85 | ///The type of the map that indicates which nodes are reached. |
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| 86 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 87 | ///\todo named parameter to set this type, function to read and write. |
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| 88 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
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| 89 | ///Instantiates a ReachedMap. |
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| 90 | |
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| 91 | ///This function instantiates a \ref ReachedMap. |
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| 92 | ///\param G is the graph, to which |
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| 93 | ///we would like to define the \ref ReachedMap. |
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| 94 | static ReachedMap *createReachedMap(const GR &G) |
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| 95 | { |
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| 96 | return new ReachedMap(G); |
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| 97 | } |
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| 98 | ///The type of the map that stores the dists of the nodes. |
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| 99 | |
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| 100 | ///The type of the map that stores the dists of the nodes. |
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| 101 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
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| 102 | /// |
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| 103 | typedef typename Graph::template NodeMap<int> DistMap; |
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| 104 | ///Instantiates a DistMap. |
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| 105 | |
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| 106 | ///This function instantiates a \ref DistMap. |
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| 107 | ///\param G is the graph, to which we would like to define the \ref DistMap |
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| 108 | static DistMap *createDistMap(const GR &G) |
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| 109 | { |
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| 110 | return new DistMap(G); |
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| 111 | } |
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| 112 | }; |
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| 113 | |
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[781] | 114 | ///%DFS algorithm class. |
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[1218] | 115 | |
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| 116 | ///\ingroup flowalgs |
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| 117 | ///This class provides an efficient implementation of the %DFS algorithm. |
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[780] | 118 | /// |
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[1218] | 119 | ///\param GR The graph type the algorithm runs on. The default value is |
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| 120 | ///\ref ListGraph. The value of GR is not used directly by Dfs, it |
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| 121 | ///is only passed to \ref DfsDefaultTraits. |
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| 122 | ///\param TR Traits class to set various data types used by the algorithm. |
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| 123 | ///The default traits class is |
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| 124 | ///\ref DfsDefaultTraits "DfsDefaultTraits<GR>". |
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| 125 | ///See \ref DfsDefaultTraits for the documentation of |
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| 126 | ///a Dfs traits class. |
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[780] | 127 | /// |
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[1218] | 128 | ///\author Jacint Szabo and Alpar Juttner |
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[780] | 129 | #ifdef DOXYGEN |
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[1218] | 130 | template <typename GR, |
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| 131 | typename TR> |
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[780] | 132 | #else |
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[1218] | 133 | template <typename GR=ListGraph, |
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| 134 | typename TR=DfsDefaultTraits<GR> > |
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[780] | 135 | #endif |
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[1218] | 136 | class Dfs { |
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[780] | 137 | public: |
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[1218] | 138 | /** |
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| 139 | * \brief \ref Exception for uninitialized parameters. |
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| 140 | * |
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| 141 | * This error represents problems in the initialization |
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| 142 | * of the parameters of the algorithms. |
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| 143 | */ |
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| 144 | class UninitializedParameter : public lemon::UninitializedParameter { |
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| 145 | public: |
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| 146 | virtual const char* exceptionName() const { |
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| 147 | return "lemon::Dfs::UninitializedParameter"; |
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| 148 | } |
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| 149 | }; |
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| 150 | |
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| 151 | typedef TR Traits; |
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[780] | 152 | ///The type of the underlying graph. |
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[1218] | 153 | typedef typename TR::Graph Graph; |
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[911] | 154 | ///\e |
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[780] | 155 | typedef typename Graph::Node Node; |
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[911] | 156 | ///\e |
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[780] | 157 | typedef typename Graph::NodeIt NodeIt; |
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[911] | 158 | ///\e |
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[780] | 159 | typedef typename Graph::Edge Edge; |
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[911] | 160 | ///\e |
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[780] | 161 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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| 162 | |
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| 163 | ///\brief The type of the map that stores the last |
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[1218] | 164 | ///edges of the %DFS paths. |
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| 165 | typedef typename TR::PredMap PredMap; |
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| 166 | ///The type of the map indicating which nodes are reached. |
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| 167 | typedef typename TR::ReachedMap ReachedMap; |
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| 168 | ///The type of the map indicating which nodes are processed. |
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| 169 | typedef typename TR::ProcessedMap ProcessedMap; |
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| 170 | ///The type of the map that stores the dists of the nodes. |
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| 171 | typedef typename TR::DistMap DistMap; |
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[780] | 172 | private: |
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[802] | 173 | /// Pointer to the underlying graph. |
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[780] | 174 | const Graph *G; |
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[802] | 175 | ///Pointer to the map of predecessors edges. |
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[1218] | 176 | PredMap *_pred; |
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| 177 | ///Indicates if \ref _pred is locally allocated (\c true) or not. |
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| 178 | bool local_pred; |
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[802] | 179 | ///Pointer to the map of distances. |
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[1218] | 180 | DistMap *_dist; |
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| 181 | ///Indicates if \ref _dist is locally allocated (\c true) or not. |
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| 182 | bool local_dist; |
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| 183 | ///Pointer to the map of reached status of the nodes. |
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| 184 | ReachedMap *_reached; |
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| 185 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
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| 186 | bool local_reached; |
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| 187 | ///Pointer to the map of processed status of the nodes. |
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| 188 | ProcessedMap *_processed; |
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| 189 | ///Indicates if \ref _processed is locally allocated (\c true) or not. |
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| 190 | bool local_processed; |
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[780] | 191 | |
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[1218] | 192 | std::vector<typename Graph::OutEdgeIt> _stack; |
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| 193 | int _stack_head; |
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[780] | 194 | |
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[1218] | 195 | ///Creates the maps if necessary. |
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| 196 | |
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| 197 | ///\todo Better memory allocation (instead of new). |
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| 198 | void create_maps() |
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[780] | 199 | { |
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[1218] | 200 | if(!_pred) { |
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| 201 | local_pred = true; |
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| 202 | _pred = Traits::createPredMap(*G); |
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[780] | 203 | } |
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[1218] | 204 | if(!_dist) { |
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| 205 | local_dist = true; |
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| 206 | _dist = Traits::createDistMap(*G); |
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[780] | 207 | } |
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[1218] | 208 | if(!_reached) { |
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| 209 | local_reached = true; |
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| 210 | _reached = Traits::createReachedMap(*G); |
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| 211 | } |
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| 212 | if(!_processed) { |
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| 213 | local_processed = true; |
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| 214 | _processed = Traits::createProcessedMap(*G); |
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[780] | 215 | } |
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| 216 | } |
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[1710] | 217 | |
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| 218 | protected: |
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| 219 | |
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| 220 | Dfs() {} |
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[780] | 221 | |
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[1710] | 222 | public: |
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[1709] | 223 | |
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| 224 | typedef Dfs Create; |
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| 225 | |
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[1218] | 226 | ///\name Named template parameters |
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| 227 | |
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| 228 | ///@{ |
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| 229 | |
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| 230 | template <class T> |
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| 231 | struct DefPredMapTraits : public Traits { |
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| 232 | typedef T PredMap; |
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| 233 | static PredMap *createPredMap(const Graph &G) |
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| 234 | { |
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| 235 | throw UninitializedParameter(); |
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| 236 | } |
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| 237 | }; |
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| 238 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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| 239 | |
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| 240 | ///\ref named-templ-param "Named parameter" for setting PredMap type |
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| 241 | /// |
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| 242 | template <class T> |
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[1709] | 243 | struct DefPredMap : public Dfs<Graph, DefPredMapTraits<T> > { |
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| 244 | typedef Dfs<Graph, DefPredMapTraits<T> > Create; |
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| 245 | }; |
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[1218] | 246 | |
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| 247 | |
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| 248 | template <class T> |
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| 249 | struct DefDistMapTraits : public Traits { |
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| 250 | typedef T DistMap; |
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| 251 | static DistMap *createDistMap(const Graph &G) |
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| 252 | { |
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| 253 | throw UninitializedParameter(); |
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| 254 | } |
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| 255 | }; |
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| 256 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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| 257 | |
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| 258 | ///\ref named-templ-param "Named parameter" for setting DistMap type |
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| 259 | /// |
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| 260 | template <class T> |
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[1709] | 261 | struct DefDistMap { |
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| 262 | typedef Dfs<Graph, DefDistMapTraits<T> > Create; |
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| 263 | }; |
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[1218] | 264 | |
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| 265 | template <class T> |
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| 266 | struct DefReachedMapTraits : public Traits { |
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| 267 | typedef T ReachedMap; |
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| 268 | static ReachedMap *createReachedMap(const Graph &G) |
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| 269 | { |
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| 270 | throw UninitializedParameter(); |
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| 271 | } |
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| 272 | }; |
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| 273 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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| 274 | |
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| 275 | ///\ref named-templ-param "Named parameter" for setting ReachedMap type |
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| 276 | /// |
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| 277 | template <class T> |
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[1749] | 278 | struct DefReachedMap : public Dfs< Graph, DefReachedMapTraits<T> > { |
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[1709] | 279 | typedef Dfs< Graph, DefReachedMapTraits<T> > Create; |
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[1218] | 280 | }; |
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[1709] | 281 | |
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[1218] | 282 | template <class T> |
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| 283 | struct DefProcessedMapTraits : public Traits { |
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| 284 | typedef T ProcessedMap; |
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| 285 | static ProcessedMap *createProcessedMap(const Graph &G) |
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| 286 | { |
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| 287 | throw UninitializedParameter(); |
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| 288 | } |
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| 289 | }; |
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| 290 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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| 291 | |
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| 292 | ///\ref named-templ-param "Named parameter" for setting ProcessedMap type |
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| 293 | /// |
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| 294 | template <class T> |
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[1694] | 295 | struct DefProcessedMap : public Dfs< Graph, DefProcessedMapTraits<T> > { |
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[1709] | 296 | typedef Dfs< Graph, DefProcessedMapTraits<T> > Create; |
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[1694] | 297 | }; |
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[1218] | 298 | |
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| 299 | struct DefGraphProcessedMapTraits : public Traits { |
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| 300 | typedef typename Graph::template NodeMap<bool> ProcessedMap; |
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| 301 | static ProcessedMap *createProcessedMap(const Graph &G) |
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| 302 | { |
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| 303 | return new ProcessedMap(G); |
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| 304 | } |
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| 305 | }; |
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| 306 | ///\brief \ref named-templ-param "Named parameter" |
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| 307 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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| 308 | /// |
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| 309 | ///\ref named-templ-param "Named parameter" |
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| 310 | ///for setting the ProcessedMap type to be Graph::NodeMap<bool>. |
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| 311 | ///If you don't set it explicitely, it will be automatically allocated. |
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| 312 | template <class T> |
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| 313 | class DefProcessedMapToBeDefaultMap : |
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[1709] | 314 | public Dfs< Graph, DefGraphProcessedMapTraits> { |
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| 315 | typedef Dfs< Graph, DefGraphProcessedMapTraits> Create; |
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| 316 | }; |
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[1218] | 317 | |
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| 318 | ///@} |
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| 319 | |
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| 320 | public: |
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| 321 | |
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[802] | 322 | ///Constructor. |
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| 323 | |
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| 324 | ///\param _G the graph the algorithm will run on. |
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[911] | 325 | /// |
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[780] | 326 | Dfs(const Graph& _G) : |
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| 327 | G(&_G), |
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[1218] | 328 | _pred(NULL), local_pred(false), |
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| 329 | _dist(NULL), local_dist(false), |
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| 330 | _reached(NULL), local_reached(false), |
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| 331 | _processed(NULL), local_processed(false) |
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[780] | 332 | { } |
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| 333 | |
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[802] | 334 | ///Destructor. |
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[780] | 335 | ~Dfs() |
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| 336 | { |
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[1218] | 337 | if(local_pred) delete _pred; |
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| 338 | if(local_dist) delete _dist; |
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| 339 | if(local_reached) delete _reached; |
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| 340 | if(local_processed) delete _processed; |
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[780] | 341 | } |
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| 342 | |
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| 343 | ///Sets the map storing the predecessor edges. |
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| 344 | |
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| 345 | ///Sets the map storing the predecessor edges. |
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| 346 | ///If you don't use this function before calling \ref run(), |
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| 347 | ///it will allocate one. The destuctor deallocates this |
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| 348 | ///automatically allocated map, of course. |
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| 349 | ///\return <tt> (*this) </tt> |
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[1218] | 350 | Dfs &predMap(PredMap &m) |
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[780] | 351 | { |
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[1218] | 352 | if(local_pred) { |
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| 353 | delete _pred; |
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| 354 | local_pred=false; |
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[780] | 355 | } |
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[1218] | 356 | _pred = &m; |
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[780] | 357 | return *this; |
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| 358 | } |
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| 359 | |
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| 360 | ///Sets the map storing the distances calculated by the algorithm. |
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| 361 | |
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| 362 | ///Sets the map storing the distances calculated by the algorithm. |
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| 363 | ///If you don't use this function before calling \ref run(), |
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| 364 | ///it will allocate one. The destuctor deallocates this |
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| 365 | ///automatically allocated map, of course. |
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| 366 | ///\return <tt> (*this) </tt> |
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[1218] | 367 | Dfs &distMap(DistMap &m) |
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[780] | 368 | { |
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[1218] | 369 | if(local_dist) { |
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| 370 | delete _dist; |
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| 371 | local_dist=false; |
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[780] | 372 | } |
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[1218] | 373 | _dist = &m; |
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[780] | 374 | return *this; |
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| 375 | } |
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| 376 | |
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[1220] | 377 | ///Sets the map indicating if a node is reached. |
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| 378 | |
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| 379 | ///Sets the map indicating if a node is reached. |
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| 380 | ///If you don't use this function before calling \ref run(), |
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| 381 | ///it will allocate one. The destuctor deallocates this |
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| 382 | ///automatically allocated map, of course. |
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| 383 | ///\return <tt> (*this) </tt> |
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| 384 | Dfs &reachedMap(ReachedMap &m) |
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| 385 | { |
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| 386 | if(local_reached) { |
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| 387 | delete _reached; |
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| 388 | local_reached=false; |
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| 389 | } |
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| 390 | _reached = &m; |
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| 391 | return *this; |
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| 392 | } |
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| 393 | |
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| 394 | ///Sets the map indicating if a node is processed. |
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| 395 | |
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| 396 | ///Sets the map indicating if a node is processed. |
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| 397 | ///If you don't use this function before calling \ref run(), |
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| 398 | ///it will allocate one. The destuctor deallocates this |
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| 399 | ///automatically allocated map, of course. |
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| 400 | ///\return <tt> (*this) </tt> |
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| 401 | Dfs &processedMap(ProcessedMap &m) |
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| 402 | { |
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| 403 | if(local_processed) { |
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| 404 | delete _processed; |
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| 405 | local_processed=false; |
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| 406 | } |
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| 407 | _processed = &m; |
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| 408 | return *this; |
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| 409 | } |
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| 410 | |
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[1218] | 411 | public: |
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| 412 | ///\name Execution control |
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| 413 | ///The simplest way to execute the algorithm is to use |
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| 414 | ///one of the member functions called \c run(...). |
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| 415 | ///\n |
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| 416 | ///If you need more control on the execution, |
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[1761] | 417 | ///first you must call \ref init(), then you can add a source node |
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[1218] | 418 | ///with \ref addSource(). |
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| 419 | ///Finally \ref start() will perform the actual path |
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| 420 | ///computation. |
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| 421 | |
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| 422 | ///@{ |
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| 423 | |
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| 424 | ///Initializes the internal data structures. |
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| 425 | |
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| 426 | ///Initializes the internal data structures. |
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| 427 | /// |
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| 428 | void init() |
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| 429 | { |
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| 430 | create_maps(); |
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| 431 | _stack.resize(countNodes(*G)); |
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| 432 | _stack_head=-1; |
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[780] | 433 | for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
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[1218] | 434 | _pred->set(u,INVALID); |
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| 435 | // _predNode->set(u,INVALID); |
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| 436 | _reached->set(u,false); |
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| 437 | _processed->set(u,false); |
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[780] | 438 | } |
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| 439 | } |
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| 440 | |
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[1218] | 441 | ///Adds a new source node. |
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[780] | 442 | |
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[1218] | 443 | ///Adds a new source node to the set of nodes to be processed. |
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| 444 | /// |
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[1874] | 445 | ///\warning dists are wrong (or at least strange) |
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| 446 | ///in case of multiple sources. |
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[1218] | 447 | void addSource(Node s) |
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| 448 | { |
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| 449 | if(!(*_reached)[s]) |
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| 450 | { |
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| 451 | _reached->set(s,true); |
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| 452 | _pred->set(s,INVALID); |
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[1664] | 453 | OutEdgeIt e(*G,s); |
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[1666] | 454 | if(e!=INVALID) { |
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| 455 | _stack[++_stack_head]=e; |
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| 456 | _dist->set(s,_stack_head); |
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| 457 | } |
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| 458 | else { |
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| 459 | _processed->set(s,true); |
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| 460 | _dist->set(s,0); |
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| 461 | } |
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[1218] | 462 | } |
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| 463 | } |
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| 464 | |
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[1529] | 465 | ///Processes the next edge. |
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[1218] | 466 | |
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[1529] | 467 | ///Processes the next edge. |
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[1218] | 468 | /// |
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[1516] | 469 | ///\return The processed edge. |
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| 470 | /// |
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[1443] | 471 | ///\pre The stack must not be empty! |
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[1516] | 472 | Edge processNextEdge() |
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[1218] | 473 | { |
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| 474 | Node m; |
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| 475 | Edge e=_stack[_stack_head]; |
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| 476 | if(!(*_reached)[m=G->target(e)]) { |
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| 477 | _pred->set(m,e); |
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| 478 | _reached->set(m,true); |
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[1233] | 479 | ++_stack_head; |
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| 480 | _stack[_stack_head] = OutEdgeIt(*G, m); |
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[1218] | 481 | _dist->set(m,_stack_head); |
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| 482 | } |
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| 483 | else { |
---|
[1663] | 484 | m=G->source(e); |
---|
| 485 | ++_stack[_stack_head]; |
---|
| 486 | } |
---|
| 487 | while(_stack_head>=0 && _stack[_stack_head]==INVALID) { |
---|
| 488 | _processed->set(m,true); |
---|
| 489 | --_stack_head; |
---|
| 490 | if(_stack_head>=0) { |
---|
| 491 | m=G->source(_stack[_stack_head]); |
---|
| 492 | ++_stack[_stack_head]; |
---|
| 493 | } |
---|
[1218] | 494 | } |
---|
[1516] | 495 | return e; |
---|
[1218] | 496 | } |
---|
[1665] | 497 | ///Next edge to be processed. |
---|
| 498 | |
---|
| 499 | ///Next edge to be processed. |
---|
| 500 | /// |
---|
| 501 | ///\return The next edge to be processed or INVALID if the stack is |
---|
| 502 | /// empty. |
---|
[1694] | 503 | OutEdgeIt nextEdge() |
---|
[1665] | 504 | { |
---|
| 505 | return _stack_head>=0?_stack[_stack_head]:INVALID; |
---|
| 506 | } |
---|
[1694] | 507 | |
---|
[1218] | 508 | ///\brief Returns \c false if there are nodes |
---|
| 509 | ///to be processed in the queue |
---|
| 510 | /// |
---|
| 511 | ///Returns \c false if there are nodes |
---|
| 512 | ///to be processed in the queue |
---|
| 513 | bool emptyQueue() { return _stack_head<0; } |
---|
| 514 | ///Returns the number of the nodes to be processed. |
---|
| 515 | |
---|
| 516 | ///Returns the number of the nodes to be processed in the queue. |
---|
| 517 | int queueSize() { return _stack_head+1; } |
---|
| 518 | |
---|
| 519 | ///Executes the algorithm. |
---|
| 520 | |
---|
| 521 | ///Executes the algorithm. |
---|
| 522 | /// |
---|
| 523 | ///\pre init() must be called and at least one node should be added |
---|
| 524 | ///with addSource() before using this function. |
---|
| 525 | /// |
---|
| 526 | ///This method runs the %DFS algorithm from the root node(s) |
---|
| 527 | ///in order to |
---|
| 528 | ///compute the |
---|
| 529 | ///%DFS path to each node. The algorithm computes |
---|
| 530 | ///- The %DFS tree. |
---|
[1443] | 531 | ///- The distance of each node from the root(s) in the %DFS tree. |
---|
[1218] | 532 | /// |
---|
| 533 | void start() |
---|
| 534 | { |
---|
| 535 | while ( !emptyQueue() ) processNextEdge(); |
---|
| 536 | } |
---|
| 537 | |
---|
| 538 | ///Executes the algorithm until \c dest is reached. |
---|
| 539 | |
---|
| 540 | ///Executes the algorithm until \c dest is reached. |
---|
| 541 | /// |
---|
| 542 | ///\pre init() must be called and at least one node should be added |
---|
| 543 | ///with addSource() before using this function. |
---|
| 544 | /// |
---|
| 545 | ///This method runs the %DFS algorithm from the root node(s) |
---|
| 546 | ///in order to |
---|
| 547 | ///compute the |
---|
| 548 | ///%DFS path to \c dest. The algorithm computes |
---|
| 549 | ///- The %DFS path to \c dest. |
---|
[1443] | 550 | ///- The distance of \c dest from the root(s) in the %DFS tree. |
---|
[1218] | 551 | /// |
---|
| 552 | void start(Node dest) |
---|
| 553 | { |
---|
[1233] | 554 | while ( !emptyQueue() && G->target(_stack[_stack_head])!=dest ) |
---|
| 555 | processNextEdge(); |
---|
[1218] | 556 | } |
---|
| 557 | |
---|
| 558 | ///Executes the algorithm until a condition is met. |
---|
| 559 | |
---|
| 560 | ///Executes the algorithm until a condition is met. |
---|
| 561 | /// |
---|
| 562 | ///\pre init() must be called and at least one node should be added |
---|
| 563 | ///with addSource() before using this function. |
---|
| 564 | /// |
---|
[1865] | 565 | ///\param em must be a bool (or convertible) edge map. The algorithm |
---|
| 566 | ///will stop when it reaches an edge \c e with \code em[e]==true \endcode. |
---|
[1443] | 567 | /// |
---|
[1749] | 568 | ///\warning Contrary to \ref Dfs and \ref Dijkstra, \c em is an edge map, |
---|
[1233] | 569 | ///not a node map. |
---|
[1749] | 570 | template<class EM> |
---|
| 571 | void start(const EM &em) |
---|
| 572 | { |
---|
| 573 | while ( !emptyQueue() && !em[_stack[_stack_head]] ) processNextEdge(); |
---|
| 574 | } |
---|
| 575 | |
---|
[1981] | 576 | ///Runs %DFS algorithm to visit all nodes in the graph. |
---|
| 577 | |
---|
| 578 | ///This method runs the %DFS algorithm in order to |
---|
| 579 | ///compute the |
---|
| 580 | ///%DFS path to each node. The algorithm computes |
---|
| 581 | ///- The %DFS tree. |
---|
| 582 | ///- The distance of each node from the root in the %DFS tree. |
---|
| 583 | /// |
---|
| 584 | ///\note d.run() is just a shortcut of the following code. |
---|
| 585 | ///\code |
---|
| 586 | /// d.init(); |
---|
| 587 | /// for (NodeIt it(graph); it != INVALID; ++it) { |
---|
| 588 | /// if (!d.reached(it)) { |
---|
| 589 | /// d.addSource(it); |
---|
| 590 | /// d.start(); |
---|
| 591 | /// } |
---|
| 592 | /// } |
---|
| 593 | ///\endcode |
---|
| 594 | void run() { |
---|
| 595 | init(); |
---|
| 596 | for (NodeIt it(*G); it != INVALID; ++it) { |
---|
| 597 | if (!reached(it)) { |
---|
| 598 | addSource(it); |
---|
| 599 | start(); |
---|
| 600 | } |
---|
| 601 | } |
---|
| 602 | } |
---|
| 603 | |
---|
[1218] | 604 | ///Runs %DFS algorithm from node \c s. |
---|
| 605 | |
---|
| 606 | ///This method runs the %DFS algorithm from a root node \c s |
---|
| 607 | ///in order to |
---|
| 608 | ///compute the |
---|
| 609 | ///%DFS path to each node. The algorithm computes |
---|
| 610 | ///- The %DFS tree. |
---|
[1443] | 611 | ///- The distance of each node from the root in the %DFS tree. |
---|
[1218] | 612 | /// |
---|
| 613 | ///\note d.run(s) is just a shortcut of the following code. |
---|
| 614 | ///\code |
---|
| 615 | /// d.init(); |
---|
| 616 | /// d.addSource(s); |
---|
| 617 | /// d.start(); |
---|
| 618 | ///\endcode |
---|
| 619 | void run(Node s) { |
---|
| 620 | init(); |
---|
| 621 | addSource(s); |
---|
| 622 | start(); |
---|
| 623 | } |
---|
| 624 | |
---|
| 625 | ///Finds the %DFS path between \c s and \c t. |
---|
| 626 | |
---|
| 627 | ///Finds the %DFS path between \c s and \c t. |
---|
| 628 | /// |
---|
| 629 | ///\return The length of the %DFS s---t path if there exists one, |
---|
| 630 | ///0 otherwise. |
---|
[1540] | 631 | ///\note Apart from the return value, d.run(s,t) is |
---|
[1218] | 632 | ///just a shortcut of the following code. |
---|
| 633 | ///\code |
---|
| 634 | /// d.init(); |
---|
| 635 | /// d.addSource(s); |
---|
| 636 | /// d.start(t); |
---|
| 637 | ///\endcode |
---|
| 638 | int run(Node s,Node t) { |
---|
| 639 | init(); |
---|
| 640 | addSource(s); |
---|
| 641 | start(t); |
---|
[1233] | 642 | return reached(t)?_stack_head+1:0; |
---|
[1218] | 643 | } |
---|
| 644 | |
---|
| 645 | ///@} |
---|
| 646 | |
---|
| 647 | ///\name Query Functions |
---|
| 648 | ///The result of the %DFS algorithm can be obtained using these |
---|
| 649 | ///functions.\n |
---|
| 650 | ///Before the use of these functions, |
---|
| 651 | ///either run() or start() must be called. |
---|
| 652 | |
---|
| 653 | ///@{ |
---|
| 654 | |
---|
[1283] | 655 | ///Copies the path to \c t on the DFS tree into \c p |
---|
| 656 | |
---|
[1443] | 657 | ///This function copies the path to \c t on the DFS tree into \c p. |
---|
[1438] | 658 | ///If \c t is a source itself or unreachable, then it does not |
---|
[1283] | 659 | ///alter \c p. |
---|
[1438] | 660 | /// |
---|
[1283] | 661 | ///\return Returns \c true if a path to \c t was actually copied to \c p, |
---|
| 662 | ///\c false otherwise. |
---|
| 663 | ///\sa DirPath |
---|
| 664 | template<class P> |
---|
| 665 | bool getPath(P &p,Node t) |
---|
| 666 | { |
---|
| 667 | if(reached(t)) { |
---|
| 668 | p.clear(); |
---|
| 669 | typename P::Builder b(p); |
---|
[1763] | 670 | for(b.setStartNode(t);predEdge(t)!=INVALID;t=predNode(t)) |
---|
| 671 | b.pushFront(predEdge(t)); |
---|
[1283] | 672 | b.commit(); |
---|
| 673 | return true; |
---|
| 674 | } |
---|
| 675 | return false; |
---|
| 676 | } |
---|
| 677 | |
---|
[1218] | 678 | ///The distance of a node from the root(s). |
---|
| 679 | |
---|
| 680 | ///Returns the distance of a node from the root(s). |
---|
[780] | 681 | ///\pre \ref run() must be called before using this function. |
---|
[1981] | 682 | ///\warning If node \c v is unreachable from the root(s) then the return |
---|
| 683 | ///value of this funcion is undefined. |
---|
[1218] | 684 | int dist(Node v) const { return (*_dist)[v]; } |
---|
[780] | 685 | |
---|
[1218] | 686 | ///Returns the 'previous edge' of the %DFS tree. |
---|
[780] | 687 | |
---|
[1218] | 688 | ///For a node \c v it returns the 'previous edge' |
---|
| 689 | ///of the %DFS path, |
---|
| 690 | ///i.e. it returns the last edge of a %DFS path from the root(s) to \c |
---|
[780] | 691 | ///v. It is \ref INVALID |
---|
[1218] | 692 | ///if \c v is unreachable from the root(s) or \c v is a root. The |
---|
[781] | 693 | ///%DFS tree used here is equal to the %DFS tree used in |
---|
[1631] | 694 | ///\ref predNode(). |
---|
[1218] | 695 | ///\pre Either \ref run() or \ref start() must be called before using |
---|
[780] | 696 | ///this function. |
---|
[1763] | 697 | Edge predEdge(Node v) const { return (*_pred)[v];} |
---|
[780] | 698 | |
---|
[781] | 699 | ///Returns the 'previous node' of the %DFS tree. |
---|
[780] | 700 | |
---|
[1218] | 701 | ///For a node \c v it returns the 'previous node' |
---|
| 702 | ///of the %DFS tree, |
---|
| 703 | ///i.e. it returns the last but one node from a %DFS path from the |
---|
| 704 | ///root(a) to \c /v. |
---|
| 705 | ///It is INVALID if \c v is unreachable from the root(s) or |
---|
| 706 | ///if \c v itself a root. |
---|
| 707 | ///The %DFS tree used here is equal to the %DFS |
---|
[1763] | 708 | ///tree used in \ref predEdge(). |
---|
[1218] | 709 | ///\pre Either \ref run() or \ref start() must be called before |
---|
[780] | 710 | ///using this function. |
---|
[1218] | 711 | Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
---|
| 712 | G->source((*_pred)[v]); } |
---|
[780] | 713 | |
---|
[1218] | 714 | ///Returns a reference to the NodeMap of distances. |
---|
| 715 | |
---|
| 716 | ///Returns a reference to the NodeMap of distances. |
---|
| 717 | ///\pre Either \ref run() or \ref init() must |
---|
[780] | 718 | ///be called before using this function. |
---|
[1218] | 719 | const DistMap &distMap() const { return *_dist;} |
---|
[780] | 720 | |
---|
[1218] | 721 | ///Returns a reference to the %DFS edge-tree map. |
---|
[780] | 722 | |
---|
| 723 | ///Returns a reference to the NodeMap of the edges of the |
---|
[781] | 724 | ///%DFS tree. |
---|
[1218] | 725 | ///\pre Either \ref run() or \ref init() |
---|
| 726 | ///must be called before using this function. |
---|
| 727 | const PredMap &predMap() const { return *_pred;} |
---|
[780] | 728 | |
---|
| 729 | ///Checks if a node is reachable from the root. |
---|
| 730 | |
---|
[1438] | 731 | ///Returns \c true if \c v is reachable from the root(s). |
---|
| 732 | ///\warning The source nodes are inditated as unreachable. |
---|
[1218] | 733 | ///\pre Either \ref run() or \ref start() |
---|
| 734 | ///must be called before using this function. |
---|
[780] | 735 | /// |
---|
[1218] | 736 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 737 | |
---|
| 738 | ///@} |
---|
| 739 | }; |
---|
| 740 | |
---|
| 741 | ///Default traits class of Dfs function. |
---|
| 742 | |
---|
| 743 | ///Default traits class of Dfs function. |
---|
| 744 | ///\param GR Graph type. |
---|
| 745 | template<class GR> |
---|
| 746 | struct DfsWizardDefaultTraits |
---|
| 747 | { |
---|
| 748 | ///The graph type the algorithm runs on. |
---|
| 749 | typedef GR Graph; |
---|
| 750 | ///\brief The type of the map that stores the last |
---|
| 751 | ///edges of the %DFS paths. |
---|
| 752 | /// |
---|
| 753 | ///The type of the map that stores the last |
---|
| 754 | ///edges of the %DFS paths. |
---|
| 755 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
[780] | 756 | /// |
---|
[1218] | 757 | typedef NullMap<typename Graph::Node,typename GR::Edge> PredMap; |
---|
| 758 | ///Instantiates a PredMap. |
---|
| 759 | |
---|
| 760 | ///This function instantiates a \ref PredMap. |
---|
[1536] | 761 | ///\param g is the graph, to which we would like to define the PredMap. |
---|
[1218] | 762 | ///\todo The graph alone may be insufficient to initialize |
---|
[1536] | 763 | #ifdef DOXYGEN |
---|
| 764 | static PredMap *createPredMap(const GR &g) |
---|
| 765 | #else |
---|
[1367] | 766 | static PredMap *createPredMap(const GR &) |
---|
[1536] | 767 | #endif |
---|
[1218] | 768 | { |
---|
| 769 | return new PredMap(); |
---|
| 770 | } |
---|
| 771 | |
---|
| 772 | ///The type of the map that indicates which nodes are processed. |
---|
| 773 | |
---|
| 774 | ///The type of the map that indicates which nodes are processed. |
---|
| 775 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 776 | ///\todo named parameter to set this type, function to read and write. |
---|
| 777 | typedef NullMap<typename Graph::Node,bool> ProcessedMap; |
---|
| 778 | ///Instantiates a ProcessedMap. |
---|
| 779 | |
---|
| 780 | ///This function instantiates a \ref ProcessedMap. |
---|
[1536] | 781 | ///\param g is the graph, to which |
---|
[1218] | 782 | ///we would like to define the \ref ProcessedMap |
---|
[1536] | 783 | #ifdef DOXYGEN |
---|
| 784 | static ProcessedMap *createProcessedMap(const GR &g) |
---|
| 785 | #else |
---|
[1367] | 786 | static ProcessedMap *createProcessedMap(const GR &) |
---|
[1536] | 787 | #endif |
---|
[1218] | 788 | { |
---|
| 789 | return new ProcessedMap(); |
---|
| 790 | } |
---|
| 791 | ///The type of the map that indicates which nodes are reached. |
---|
| 792 | |
---|
| 793 | ///The type of the map that indicates which nodes are reached. |
---|
| 794 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 795 | ///\todo named parameter to set this type, function to read and write. |
---|
| 796 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 797 | ///Instantiates a ReachedMap. |
---|
| 798 | |
---|
| 799 | ///This function instantiates a \ref ReachedMap. |
---|
| 800 | ///\param G is the graph, to which |
---|
| 801 | ///we would like to define the \ref ReachedMap. |
---|
| 802 | static ReachedMap *createReachedMap(const GR &G) |
---|
| 803 | { |
---|
| 804 | return new ReachedMap(G); |
---|
| 805 | } |
---|
| 806 | ///The type of the map that stores the dists of the nodes. |
---|
| 807 | |
---|
| 808 | ///The type of the map that stores the dists of the nodes. |
---|
| 809 | ///It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 810 | /// |
---|
| 811 | typedef NullMap<typename Graph::Node,int> DistMap; |
---|
| 812 | ///Instantiates a DistMap. |
---|
| 813 | |
---|
| 814 | ///This function instantiates a \ref DistMap. |
---|
[1536] | 815 | ///\param g is the graph, to which we would like to define the \ref DistMap |
---|
| 816 | #ifdef DOXYGEN |
---|
| 817 | static DistMap *createDistMap(const GR &g) |
---|
| 818 | #else |
---|
[1367] | 819 | static DistMap *createDistMap(const GR &) |
---|
[1536] | 820 | #endif |
---|
[1218] | 821 | { |
---|
| 822 | return new DistMap(); |
---|
| 823 | } |
---|
| 824 | }; |
---|
| 825 | |
---|
| 826 | /// Default traits used by \ref DfsWizard |
---|
| 827 | |
---|
| 828 | /// To make it easier to use Dfs algorithm |
---|
| 829 | ///we have created a wizard class. |
---|
| 830 | /// This \ref DfsWizard class needs default traits, |
---|
| 831 | ///as well as the \ref Dfs class. |
---|
| 832 | /// The \ref DfsWizardBase is a class to be the default traits of the |
---|
| 833 | /// \ref DfsWizard class. |
---|
| 834 | template<class GR> |
---|
| 835 | class DfsWizardBase : public DfsWizardDefaultTraits<GR> |
---|
| 836 | { |
---|
| 837 | |
---|
| 838 | typedef DfsWizardDefaultTraits<GR> Base; |
---|
| 839 | protected: |
---|
| 840 | /// Type of the nodes in the graph. |
---|
| 841 | typedef typename Base::Graph::Node Node; |
---|
| 842 | |
---|
| 843 | /// Pointer to the underlying graph. |
---|
| 844 | void *_g; |
---|
| 845 | ///Pointer to the map of reached nodes. |
---|
| 846 | void *_reached; |
---|
| 847 | ///Pointer to the map of processed nodes. |
---|
| 848 | void *_processed; |
---|
| 849 | ///Pointer to the map of predecessors edges. |
---|
| 850 | void *_pred; |
---|
| 851 | ///Pointer to the map of distances. |
---|
| 852 | void *_dist; |
---|
| 853 | ///Pointer to the source node. |
---|
| 854 | Node _source; |
---|
| 855 | |
---|
| 856 | public: |
---|
| 857 | /// Constructor. |
---|
| 858 | |
---|
| 859 | /// This constructor does not require parameters, therefore it initiates |
---|
| 860 | /// all of the attributes to default values (0, INVALID). |
---|
| 861 | DfsWizardBase() : _g(0), _reached(0), _processed(0), _pred(0), |
---|
| 862 | _dist(0), _source(INVALID) {} |
---|
| 863 | |
---|
| 864 | /// Constructor. |
---|
| 865 | |
---|
| 866 | /// This constructor requires some parameters, |
---|
| 867 | /// listed in the parameters list. |
---|
| 868 | /// Others are initiated to 0. |
---|
| 869 | /// \param g is the initial value of \ref _g |
---|
| 870 | /// \param s is the initial value of \ref _source |
---|
| 871 | DfsWizardBase(const GR &g, Node s=INVALID) : |
---|
| 872 | _g((void *)&g), _reached(0), _processed(0), _pred(0), |
---|
| 873 | _dist(0), _source(s) {} |
---|
| 874 | |
---|
| 875 | }; |
---|
| 876 | |
---|
[1443] | 877 | /// A class to make the usage of the Dfs algorithm easier |
---|
[1218] | 878 | |
---|
[1443] | 879 | /// This class is created to make it easier to use the Dfs algorithm. |
---|
[1218] | 880 | /// It uses the functions and features of the plain \ref Dfs, |
---|
| 881 | /// but it is much simpler to use it. |
---|
| 882 | /// |
---|
| 883 | /// Simplicity means that the way to change the types defined |
---|
| 884 | /// in the traits class is based on functions that returns the new class |
---|
| 885 | /// and not on templatable built-in classes. |
---|
| 886 | /// When using the plain \ref Dfs |
---|
| 887 | /// the new class with the modified type comes from |
---|
| 888 | /// the original class by using the :: |
---|
| 889 | /// operator. In the case of \ref DfsWizard only |
---|
| 890 | /// a function have to be called and it will |
---|
| 891 | /// return the needed class. |
---|
| 892 | /// |
---|
| 893 | /// It does not have own \ref run method. When its \ref run method is called |
---|
[1438] | 894 | /// it initiates a plain \ref Dfs object, and calls the \ref Dfs::run |
---|
[1218] | 895 | /// method of it. |
---|
| 896 | template<class TR> |
---|
| 897 | class DfsWizard : public TR |
---|
| 898 | { |
---|
| 899 | typedef TR Base; |
---|
| 900 | |
---|
| 901 | ///The type of the underlying graph. |
---|
| 902 | typedef typename TR::Graph Graph; |
---|
| 903 | //\e |
---|
| 904 | typedef typename Graph::Node Node; |
---|
| 905 | //\e |
---|
| 906 | typedef typename Graph::NodeIt NodeIt; |
---|
| 907 | //\e |
---|
| 908 | typedef typename Graph::Edge Edge; |
---|
| 909 | //\e |
---|
| 910 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 911 | |
---|
| 912 | ///\brief The type of the map that stores |
---|
| 913 | ///the reached nodes |
---|
| 914 | typedef typename TR::ReachedMap ReachedMap; |
---|
| 915 | ///\brief The type of the map that stores |
---|
| 916 | ///the processed nodes |
---|
| 917 | typedef typename TR::ProcessedMap ProcessedMap; |
---|
| 918 | ///\brief The type of the map that stores the last |
---|
| 919 | ///edges of the %DFS paths. |
---|
| 920 | typedef typename TR::PredMap PredMap; |
---|
[1443] | 921 | ///The type of the map that stores the distances of the nodes. |
---|
[1218] | 922 | typedef typename TR::DistMap DistMap; |
---|
| 923 | |
---|
| 924 | public: |
---|
| 925 | /// Constructor. |
---|
| 926 | DfsWizard() : TR() {} |
---|
| 927 | |
---|
| 928 | /// Constructor that requires parameters. |
---|
| 929 | |
---|
| 930 | /// Constructor that requires parameters. |
---|
| 931 | /// These parameters will be the default values for the traits class. |
---|
| 932 | DfsWizard(const Graph &g, Node s=INVALID) : |
---|
| 933 | TR(g,s) {} |
---|
| 934 | |
---|
| 935 | ///Copy constructor |
---|
| 936 | DfsWizard(const TR &b) : TR(b) {} |
---|
| 937 | |
---|
| 938 | ~DfsWizard() {} |
---|
| 939 | |
---|
| 940 | ///Runs Dfs algorithm from a given node. |
---|
| 941 | |
---|
| 942 | ///Runs Dfs algorithm from a given node. |
---|
| 943 | ///The node can be given by the \ref source function. |
---|
| 944 | void run() |
---|
| 945 | { |
---|
| 946 | if(Base::_source==INVALID) throw UninitializedParameter(); |
---|
| 947 | Dfs<Graph,TR> alg(*(Graph*)Base::_g); |
---|
| 948 | if(Base::_reached) alg.reachedMap(*(ReachedMap*)Base::_reached); |
---|
| 949 | if(Base::_processed) alg.processedMap(*(ProcessedMap*)Base::_processed); |
---|
| 950 | if(Base::_pred) alg.predMap(*(PredMap*)Base::_pred); |
---|
| 951 | if(Base::_dist) alg.distMap(*(DistMap*)Base::_dist); |
---|
| 952 | alg.run(Base::_source); |
---|
| 953 | } |
---|
| 954 | |
---|
| 955 | ///Runs Dfs algorithm from the given node. |
---|
| 956 | |
---|
| 957 | ///Runs Dfs algorithm from the given node. |
---|
| 958 | ///\param s is the given source. |
---|
| 959 | void run(Node s) |
---|
| 960 | { |
---|
| 961 | Base::_source=s; |
---|
| 962 | run(); |
---|
| 963 | } |
---|
| 964 | |
---|
| 965 | template<class T> |
---|
| 966 | struct DefPredMapBase : public Base { |
---|
| 967 | typedef T PredMap; |
---|
[1367] | 968 | static PredMap *createPredMap(const Graph &) { return 0; }; |
---|
[1236] | 969 | DefPredMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 970 | }; |
---|
| 971 | |
---|
| 972 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 973 | ///function for setting PredMap type |
---|
| 974 | /// |
---|
| 975 | /// \ref named-templ-param "Named parameter" |
---|
| 976 | ///function for setting PredMap type |
---|
| 977 | /// |
---|
| 978 | template<class T> |
---|
| 979 | DfsWizard<DefPredMapBase<T> > predMap(const T &t) |
---|
| 980 | { |
---|
| 981 | Base::_pred=(void *)&t; |
---|
| 982 | return DfsWizard<DefPredMapBase<T> >(*this); |
---|
| 983 | } |
---|
| 984 | |
---|
| 985 | |
---|
| 986 | template<class T> |
---|
| 987 | struct DefReachedMapBase : public Base { |
---|
| 988 | typedef T ReachedMap; |
---|
[1367] | 989 | static ReachedMap *createReachedMap(const Graph &) { return 0; }; |
---|
[1236] | 990 | DefReachedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 991 | }; |
---|
| 992 | |
---|
| 993 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 994 | ///function for setting ReachedMap |
---|
| 995 | /// |
---|
| 996 | /// \ref named-templ-param "Named parameter" |
---|
| 997 | ///function for setting ReachedMap |
---|
| 998 | /// |
---|
| 999 | template<class T> |
---|
| 1000 | DfsWizard<DefReachedMapBase<T> > reachedMap(const T &t) |
---|
| 1001 | { |
---|
| 1002 | Base::_pred=(void *)&t; |
---|
| 1003 | return DfsWizard<DefReachedMapBase<T> >(*this); |
---|
| 1004 | } |
---|
| 1005 | |
---|
| 1006 | |
---|
| 1007 | template<class T> |
---|
| 1008 | struct DefProcessedMapBase : public Base { |
---|
| 1009 | typedef T ProcessedMap; |
---|
[1367] | 1010 | static ProcessedMap *createProcessedMap(const Graph &) { return 0; }; |
---|
[1236] | 1011 | DefProcessedMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1012 | }; |
---|
| 1013 | |
---|
| 1014 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1015 | ///function for setting ProcessedMap |
---|
| 1016 | /// |
---|
| 1017 | /// \ref named-templ-param "Named parameter" |
---|
| 1018 | ///function for setting ProcessedMap |
---|
| 1019 | /// |
---|
| 1020 | template<class T> |
---|
| 1021 | DfsWizard<DefProcessedMapBase<T> > processedMap(const T &t) |
---|
| 1022 | { |
---|
| 1023 | Base::_pred=(void *)&t; |
---|
| 1024 | return DfsWizard<DefProcessedMapBase<T> >(*this); |
---|
| 1025 | } |
---|
| 1026 | |
---|
| 1027 | template<class T> |
---|
| 1028 | struct DefDistMapBase : public Base { |
---|
| 1029 | typedef T DistMap; |
---|
[1367] | 1030 | static DistMap *createDistMap(const Graph &) { return 0; }; |
---|
[1236] | 1031 | DefDistMapBase(const TR &b) : TR(b) {} |
---|
[1218] | 1032 | }; |
---|
| 1033 | |
---|
| 1034 | ///\brief \ref named-templ-param "Named parameter" |
---|
| 1035 | ///function for setting DistMap type |
---|
| 1036 | /// |
---|
| 1037 | /// \ref named-templ-param "Named parameter" |
---|
| 1038 | ///function for setting DistMap type |
---|
| 1039 | /// |
---|
| 1040 | template<class T> |
---|
| 1041 | DfsWizard<DefDistMapBase<T> > distMap(const T &t) |
---|
| 1042 | { |
---|
| 1043 | Base::_dist=(void *)&t; |
---|
| 1044 | return DfsWizard<DefDistMapBase<T> >(*this); |
---|
| 1045 | } |
---|
| 1046 | |
---|
| 1047 | /// Sets the source node, from which the Dfs algorithm runs. |
---|
| 1048 | |
---|
| 1049 | /// Sets the source node, from which the Dfs algorithm runs. |
---|
| 1050 | /// \param s is the source node. |
---|
| 1051 | DfsWizard<TR> &source(Node s) |
---|
| 1052 | { |
---|
| 1053 | Base::_source=s; |
---|
| 1054 | return *this; |
---|
| 1055 | } |
---|
[780] | 1056 | |
---|
| 1057 | }; |
---|
| 1058 | |
---|
[1218] | 1059 | ///Function type interface for Dfs algorithm. |
---|
| 1060 | |
---|
| 1061 | /// \ingroup flowalgs |
---|
| 1062 | ///Function type interface for Dfs algorithm. |
---|
| 1063 | /// |
---|
| 1064 | ///This function also has several |
---|
| 1065 | ///\ref named-templ-func-param "named parameters", |
---|
| 1066 | ///they are declared as the members of class \ref DfsWizard. |
---|
| 1067 | ///The following |
---|
| 1068 | ///example shows how to use these parameters. |
---|
| 1069 | ///\code |
---|
| 1070 | /// dfs(g,source).predMap(preds).run(); |
---|
| 1071 | ///\endcode |
---|
| 1072 | ///\warning Don't forget to put the \ref DfsWizard::run() "run()" |
---|
| 1073 | ///to the end of the parameter list. |
---|
| 1074 | ///\sa DfsWizard |
---|
| 1075 | ///\sa Dfs |
---|
| 1076 | template<class GR> |
---|
| 1077 | DfsWizard<DfsWizardBase<GR> > |
---|
| 1078 | dfs(const GR &g,typename GR::Node s=INVALID) |
---|
| 1079 | { |
---|
| 1080 | return DfsWizard<DfsWizardBase<GR> >(g,s); |
---|
| 1081 | } |
---|
| 1082 | |
---|
[1799] | 1083 | #ifdef DOXYGEN |
---|
[1749] | 1084 | /// \brief Visitor class for dfs. |
---|
| 1085 | /// |
---|
| 1086 | /// It gives a simple interface for a functional interface for dfs |
---|
| 1087 | /// traversal. The traversal on a linear data structure. |
---|
| 1088 | template <typename _Graph> |
---|
| 1089 | struct DfsVisitor { |
---|
| 1090 | typedef _Graph Graph; |
---|
| 1091 | typedef typename Graph::Edge Edge; |
---|
| 1092 | typedef typename Graph::Node Node; |
---|
| 1093 | /// \brief Called when the edge reach a node. |
---|
| 1094 | /// |
---|
| 1095 | /// It is called when the dfs find an edge which target is not |
---|
| 1096 | /// reached yet. |
---|
| 1097 | void discover(const Edge& edge) {} |
---|
| 1098 | /// \brief Called when the node reached first time. |
---|
| 1099 | /// |
---|
| 1100 | /// It is Called when the node reached first time. |
---|
| 1101 | void reach(const Node& node) {} |
---|
| 1102 | /// \brief Called when we step back on an edge. |
---|
| 1103 | /// |
---|
| 1104 | /// It is called when the dfs should step back on the edge. |
---|
| 1105 | void backtrack(const Edge& edge) {} |
---|
| 1106 | /// \brief Called when we step back from the node. |
---|
| 1107 | /// |
---|
| 1108 | /// It is called when we step back from the node. |
---|
| 1109 | void leave(const Node& node) {} |
---|
| 1110 | /// \brief Called when the edge examined but target of the edge |
---|
| 1111 | /// already discovered. |
---|
| 1112 | /// |
---|
| 1113 | /// It called when the edge examined but the target of the edge |
---|
| 1114 | /// already discovered. |
---|
| 1115 | void examine(const Edge& edge) {} |
---|
| 1116 | /// \brief Called for the source node of the dfs. |
---|
| 1117 | /// |
---|
| 1118 | /// It is called for the source node of the dfs. |
---|
[1799] | 1119 | void start(const Node& node) {} |
---|
[1749] | 1120 | /// \brief Called when we leave the source node of the dfs. |
---|
| 1121 | /// |
---|
| 1122 | /// It is called when we leave the source node of the dfs. |
---|
[1799] | 1123 | void stop(const Node& node) {} |
---|
| 1124 | |
---|
| 1125 | }; |
---|
| 1126 | #else |
---|
| 1127 | template <typename _Graph> |
---|
| 1128 | struct DfsVisitor { |
---|
| 1129 | typedef _Graph Graph; |
---|
| 1130 | typedef typename Graph::Edge Edge; |
---|
| 1131 | typedef typename Graph::Node Node; |
---|
| 1132 | void discover(const Edge&) {} |
---|
| 1133 | void reach(const Node&) {} |
---|
| 1134 | void backtrack(const Edge&) {} |
---|
| 1135 | void leave(const Node&) {} |
---|
| 1136 | void examine(const Edge&) {} |
---|
| 1137 | void start(const Node&) {} |
---|
[1749] | 1138 | void stop(const Node&) {} |
---|
| 1139 | |
---|
| 1140 | template <typename _Visitor> |
---|
| 1141 | struct Constraints { |
---|
| 1142 | void constraints() { |
---|
| 1143 | Edge edge; |
---|
| 1144 | Node node; |
---|
| 1145 | visitor.discover(edge); |
---|
| 1146 | visitor.reach(node); |
---|
| 1147 | visitor.backtrack(edge); |
---|
| 1148 | visitor.leave(node); |
---|
| 1149 | visitor.examine(edge); |
---|
| 1150 | visitor.start(node); |
---|
| 1151 | visitor.stop(edge); |
---|
| 1152 | } |
---|
| 1153 | _Visitor& visitor; |
---|
| 1154 | }; |
---|
| 1155 | }; |
---|
[1799] | 1156 | #endif |
---|
[1749] | 1157 | |
---|
| 1158 | /// \brief Default traits class of DfsVisit class. |
---|
| 1159 | /// |
---|
| 1160 | /// Default traits class of DfsVisit class. |
---|
| 1161 | /// \param _Graph Graph type. |
---|
| 1162 | template<class _Graph> |
---|
| 1163 | struct DfsVisitDefaultTraits { |
---|
| 1164 | |
---|
| 1165 | /// \brief The graph type the algorithm runs on. |
---|
| 1166 | typedef _Graph Graph; |
---|
| 1167 | |
---|
| 1168 | /// \brief The type of the map that indicates which nodes are reached. |
---|
| 1169 | /// |
---|
| 1170 | /// The type of the map that indicates which nodes are reached. |
---|
| 1171 | /// It must meet the \ref concept::WriteMap "WriteMap" concept. |
---|
| 1172 | /// \todo named parameter to set this type, function to read and write. |
---|
| 1173 | typedef typename Graph::template NodeMap<bool> ReachedMap; |
---|
| 1174 | |
---|
| 1175 | /// \brief Instantiates a ReachedMap. |
---|
| 1176 | /// |
---|
| 1177 | /// This function instantiates a \ref ReachedMap. |
---|
[1865] | 1178 | /// \param graph is the graph, to which |
---|
[1749] | 1179 | /// we would like to define the \ref ReachedMap. |
---|
| 1180 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1181 | return new ReachedMap(graph); |
---|
| 1182 | } |
---|
| 1183 | |
---|
| 1184 | }; |
---|
| 1185 | |
---|
| 1186 | /// %DFS Visit algorithm class. |
---|
| 1187 | |
---|
| 1188 | /// \ingroup flowalgs |
---|
| 1189 | /// This class provides an efficient implementation of the %DFS algorithm |
---|
| 1190 | /// with visitor interface. |
---|
| 1191 | /// |
---|
| 1192 | /// The %DfsVisit class provides an alternative interface to the Dfs |
---|
| 1193 | /// class. It works with callback mechanism, the DfsVisit object calls |
---|
| 1194 | /// on every dfs event the \c Visitor class member functions. |
---|
| 1195 | /// |
---|
| 1196 | /// \param _Graph The graph type the algorithm runs on. The default value is |
---|
| 1197 | /// \ref ListGraph. The value of _Graph is not used directly by Dfs, it |
---|
| 1198 | /// is only passed to \ref DfsDefaultTraits. |
---|
| 1199 | /// \param _Visitor The Visitor object for the algorithm. The |
---|
| 1200 | /// \ref DfsVisitor "DfsVisitor<_Graph>" is an empty Visitor which |
---|
| 1201 | /// does not observe the Dfs events. If you want to observe the dfs |
---|
| 1202 | /// events you should implement your own Visitor class. |
---|
| 1203 | /// \param _Traits Traits class to set various data types used by the |
---|
| 1204 | /// algorithm. The default traits class is |
---|
| 1205 | /// \ref DfsVisitDefaultTraits "DfsVisitDefaultTraits<_Graph>". |
---|
| 1206 | /// See \ref DfsVisitDefaultTraits for the documentation of |
---|
| 1207 | /// a Dfs visit traits class. |
---|
| 1208 | /// |
---|
| 1209 | /// \author Jacint Szabo, Alpar Juttner and Balazs Dezso |
---|
| 1210 | #ifdef DOXYGEN |
---|
| 1211 | template <typename _Graph, typename _Visitor, typename _Traits> |
---|
| 1212 | #else |
---|
| 1213 | template <typename _Graph = ListGraph, |
---|
| 1214 | typename _Visitor = DfsVisitor<_Graph>, |
---|
| 1215 | typename _Traits = DfsDefaultTraits<_Graph> > |
---|
| 1216 | #endif |
---|
| 1217 | class DfsVisit { |
---|
| 1218 | public: |
---|
| 1219 | |
---|
| 1220 | /// \brief \ref Exception for uninitialized parameters. |
---|
| 1221 | /// |
---|
| 1222 | /// This error represents problems in the initialization |
---|
| 1223 | /// of the parameters of the algorithms. |
---|
| 1224 | class UninitializedParameter : public lemon::UninitializedParameter { |
---|
| 1225 | public: |
---|
| 1226 | virtual const char* exceptionName() const { |
---|
| 1227 | return "lemon::DfsVisit::UninitializedParameter"; |
---|
| 1228 | } |
---|
| 1229 | }; |
---|
| 1230 | |
---|
| 1231 | typedef _Traits Traits; |
---|
| 1232 | |
---|
| 1233 | typedef typename Traits::Graph Graph; |
---|
| 1234 | |
---|
| 1235 | typedef _Visitor Visitor; |
---|
| 1236 | |
---|
| 1237 | ///The type of the map indicating which nodes are reached. |
---|
| 1238 | typedef typename Traits::ReachedMap ReachedMap; |
---|
| 1239 | |
---|
| 1240 | private: |
---|
| 1241 | |
---|
| 1242 | typedef typename Graph::Node Node; |
---|
| 1243 | typedef typename Graph::NodeIt NodeIt; |
---|
| 1244 | typedef typename Graph::Edge Edge; |
---|
| 1245 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
| 1246 | |
---|
| 1247 | /// Pointer to the underlying graph. |
---|
| 1248 | const Graph *_graph; |
---|
| 1249 | /// Pointer to the visitor object. |
---|
| 1250 | Visitor *_visitor; |
---|
| 1251 | ///Pointer to the map of reached status of the nodes. |
---|
| 1252 | ReachedMap *_reached; |
---|
| 1253 | ///Indicates if \ref _reached is locally allocated (\c true) or not. |
---|
| 1254 | bool local_reached; |
---|
| 1255 | |
---|
| 1256 | std::vector<typename Graph::Edge> _stack; |
---|
| 1257 | int _stack_head; |
---|
| 1258 | |
---|
| 1259 | /// \brief Creates the maps if necessary. |
---|
| 1260 | /// |
---|
| 1261 | /// Creates the maps if necessary. |
---|
| 1262 | void create_maps() { |
---|
| 1263 | if(!_reached) { |
---|
| 1264 | local_reached = true; |
---|
| 1265 | _reached = Traits::createReachedMap(*_graph); |
---|
| 1266 | } |
---|
| 1267 | } |
---|
| 1268 | |
---|
| 1269 | protected: |
---|
| 1270 | |
---|
| 1271 | DfsVisit() {} |
---|
| 1272 | |
---|
| 1273 | public: |
---|
| 1274 | |
---|
| 1275 | typedef DfsVisit Create; |
---|
| 1276 | |
---|
| 1277 | /// \name Named template parameters |
---|
| 1278 | |
---|
| 1279 | ///@{ |
---|
| 1280 | template <class T> |
---|
| 1281 | struct DefReachedMapTraits : public Traits { |
---|
| 1282 | typedef T ReachedMap; |
---|
| 1283 | static ReachedMap *createReachedMap(const Graph &graph) { |
---|
| 1284 | throw UninitializedParameter(); |
---|
| 1285 | } |
---|
| 1286 | }; |
---|
| 1287 | /// \brief \ref named-templ-param "Named parameter" for setting |
---|
| 1288 | /// ReachedMap type |
---|
| 1289 | /// |
---|
| 1290 | /// \ref named-templ-param "Named parameter" for setting ReachedMap type |
---|
| 1291 | template <class T> |
---|
[1773] | 1292 | struct DefReachedMap : public DfsVisit< Graph, Visitor, |
---|
| 1293 | DefReachedMapTraits<T> > { |
---|
| 1294 | typedef DfsVisit< Graph, Visitor, DefReachedMapTraits<T> > Create; |
---|
[1749] | 1295 | }; |
---|
| 1296 | ///@} |
---|
| 1297 | |
---|
| 1298 | public: |
---|
| 1299 | |
---|
| 1300 | /// \brief Constructor. |
---|
| 1301 | /// |
---|
| 1302 | /// Constructor. |
---|
| 1303 | /// |
---|
| 1304 | /// \param graph the graph the algorithm will run on. |
---|
| 1305 | /// \param visitor The visitor of the algorithm. |
---|
| 1306 | /// |
---|
| 1307 | DfsVisit(const Graph& graph, Visitor& visitor) |
---|
| 1308 | : _graph(&graph), _visitor(&visitor), |
---|
| 1309 | _reached(0), local_reached(false) {} |
---|
| 1310 | |
---|
| 1311 | /// \brief Destructor. |
---|
| 1312 | /// |
---|
| 1313 | /// Destructor. |
---|
| 1314 | ~DfsVisit() { |
---|
| 1315 | if(local_reached) delete _reached; |
---|
| 1316 | } |
---|
| 1317 | |
---|
| 1318 | /// \brief Sets the map indicating if a node is reached. |
---|
| 1319 | /// |
---|
| 1320 | /// Sets the map indicating if a node is reached. |
---|
| 1321 | /// If you don't use this function before calling \ref run(), |
---|
| 1322 | /// it will allocate one. The destuctor deallocates this |
---|
| 1323 | /// automatically allocated map, of course. |
---|
| 1324 | /// \return <tt> (*this) </tt> |
---|
| 1325 | DfsVisit &reachedMap(ReachedMap &m) { |
---|
| 1326 | if(local_reached) { |
---|
| 1327 | delete _reached; |
---|
| 1328 | local_reached=false; |
---|
| 1329 | } |
---|
| 1330 | _reached = &m; |
---|
| 1331 | return *this; |
---|
| 1332 | } |
---|
| 1333 | |
---|
| 1334 | public: |
---|
| 1335 | /// \name Execution control |
---|
| 1336 | /// The simplest way to execute the algorithm is to use |
---|
| 1337 | /// one of the member functions called \c run(...). |
---|
| 1338 | /// \n |
---|
| 1339 | /// If you need more control on the execution, |
---|
[1761] | 1340 | /// first you must call \ref init(), then you can adda source node |
---|
[1749] | 1341 | /// with \ref addSource(). |
---|
| 1342 | /// Finally \ref start() will perform the actual path |
---|
| 1343 | /// computation. |
---|
| 1344 | |
---|
| 1345 | /// @{ |
---|
| 1346 | /// \brief Initializes the internal data structures. |
---|
| 1347 | /// |
---|
| 1348 | /// Initializes the internal data structures. |
---|
| 1349 | /// |
---|
| 1350 | void init() { |
---|
| 1351 | create_maps(); |
---|
| 1352 | _stack.resize(countNodes(*_graph)); |
---|
| 1353 | _stack_head = -1; |
---|
| 1354 | for (NodeIt u(*_graph) ; u != INVALID ; ++u) { |
---|
| 1355 | _reached->set(u, false); |
---|
| 1356 | } |
---|
| 1357 | } |
---|
| 1358 | |
---|
| 1359 | /// \brief Adds a new source node. |
---|
| 1360 | /// |
---|
| 1361 | /// Adds a new source node to the set of nodes to be processed. |
---|
| 1362 | void addSource(Node s) { |
---|
| 1363 | if(!(*_reached)[s]) { |
---|
| 1364 | _reached->set(s,true); |
---|
| 1365 | _visitor->start(s); |
---|
| 1366 | _visitor->reach(s); |
---|
| 1367 | Edge e; |
---|
| 1368 | _graph->firstOut(e, s); |
---|
| 1369 | if (e != INVALID) { |
---|
| 1370 | _stack[++_stack_head] = e; |
---|
| 1371 | } else { |
---|
| 1372 | _visitor->leave(s); |
---|
| 1373 | } |
---|
| 1374 | } |
---|
| 1375 | } |
---|
| 1376 | |
---|
| 1377 | /// \brief Processes the next edge. |
---|
| 1378 | /// |
---|
| 1379 | /// Processes the next edge. |
---|
| 1380 | /// |
---|
| 1381 | /// \return The processed edge. |
---|
| 1382 | /// |
---|
| 1383 | /// \pre The stack must not be empty! |
---|
| 1384 | Edge processNextEdge() { |
---|
| 1385 | Edge e = _stack[_stack_head]; |
---|
| 1386 | Node m = _graph->target(e); |
---|
| 1387 | if(!(*_reached)[m]) { |
---|
| 1388 | _visitor->discover(e); |
---|
| 1389 | _visitor->reach(m); |
---|
| 1390 | _reached->set(m, true); |
---|
| 1391 | _graph->firstOut(_stack[++_stack_head], m); |
---|
| 1392 | } else { |
---|
| 1393 | _visitor->examine(e); |
---|
| 1394 | m = _graph->source(e); |
---|
| 1395 | _graph->nextOut(_stack[_stack_head]); |
---|
| 1396 | } |
---|
| 1397 | while (_stack_head>=0 && _stack[_stack_head] == INVALID) { |
---|
| 1398 | _visitor->leave(m); |
---|
| 1399 | --_stack_head; |
---|
| 1400 | if (_stack_head >= 0) { |
---|
| 1401 | _visitor->backtrack(_stack[_stack_head]); |
---|
| 1402 | m = _graph->source(_stack[_stack_head]); |
---|
| 1403 | _graph->nextOut(_stack[_stack_head]); |
---|
| 1404 | } else { |
---|
| 1405 | _visitor->stop(m); |
---|
| 1406 | } |
---|
| 1407 | } |
---|
| 1408 | return e; |
---|
| 1409 | } |
---|
| 1410 | |
---|
| 1411 | /// \brief Next edge to be processed. |
---|
| 1412 | /// |
---|
| 1413 | /// Next edge to be processed. |
---|
| 1414 | /// |
---|
| 1415 | /// \return The next edge to be processed or INVALID if the stack is |
---|
| 1416 | /// empty. |
---|
| 1417 | Edge nextEdge() { |
---|
| 1418 | return _stack_head >= 0 ? _stack[_stack_head] : INVALID; |
---|
| 1419 | } |
---|
| 1420 | |
---|
| 1421 | /// \brief Returns \c false if there are nodes |
---|
| 1422 | /// to be processed in the queue |
---|
| 1423 | /// |
---|
| 1424 | /// Returns \c false if there are nodes |
---|
| 1425 | /// to be processed in the queue |
---|
| 1426 | bool emptyQueue() { return _stack_head < 0; } |
---|
| 1427 | |
---|
| 1428 | /// \brief Returns the number of the nodes to be processed. |
---|
| 1429 | /// |
---|
| 1430 | /// Returns the number of the nodes to be processed in the queue. |
---|
| 1431 | int queueSize() { return _stack_head + 1; } |
---|
| 1432 | |
---|
| 1433 | /// \brief Executes the algorithm. |
---|
| 1434 | /// |
---|
| 1435 | /// Executes the algorithm. |
---|
| 1436 | /// |
---|
| 1437 | /// \pre init() must be called and at least one node should be added |
---|
| 1438 | /// with addSource() before using this function. |
---|
| 1439 | void start() { |
---|
| 1440 | while ( !emptyQueue() ) processNextEdge(); |
---|
| 1441 | } |
---|
| 1442 | |
---|
| 1443 | /// \brief Executes the algorithm until \c dest is reached. |
---|
| 1444 | /// |
---|
| 1445 | /// Executes the algorithm until \c dest is reached. |
---|
| 1446 | /// |
---|
| 1447 | /// \pre init() must be called and at least one node should be added |
---|
| 1448 | /// with addSource() before using this function. |
---|
| 1449 | void start(Node dest) { |
---|
| 1450 | while ( !emptyQueue() && _graph->target(_stack[_stack_head]) != dest) |
---|
| 1451 | processNextEdge(); |
---|
| 1452 | } |
---|
| 1453 | |
---|
| 1454 | /// \brief Executes the algorithm until a condition is met. |
---|
| 1455 | /// |
---|
| 1456 | /// Executes the algorithm until a condition is met. |
---|
| 1457 | /// |
---|
| 1458 | /// \pre init() must be called and at least one node should be added |
---|
| 1459 | /// with addSource() before using this function. |
---|
| 1460 | /// |
---|
[1865] | 1461 | /// \param em must be a bool (or convertible) edge map. The algorithm |
---|
| 1462 | /// will stop when it reaches an edge \c e with \code nm[e]==true \endcode. |
---|
[1749] | 1463 | /// |
---|
| 1464 | /// \warning Contrary to \ref Dfs and \ref Dijkstra, \c em is an edge map, |
---|
| 1465 | /// not a node map. |
---|
| 1466 | template <typename EM> |
---|
| 1467 | void start(const EM &em) { |
---|
| 1468 | while (!emptyQueue() && !em[_stack[_stack_head]]) processNextEdge(); |
---|
| 1469 | } |
---|
| 1470 | |
---|
[1981] | 1471 | /// \brief Runs %DFSVisit algorithm from node \c s. |
---|
[1749] | 1472 | /// |
---|
| 1473 | /// This method runs the %DFS algorithm from a root node \c s. |
---|
| 1474 | /// \note d.run(s) is just a shortcut of the following code. |
---|
[1946] | 1475 | ///\code |
---|
[1749] | 1476 | /// d.init(); |
---|
| 1477 | /// d.addSource(s); |
---|
| 1478 | /// d.start(); |
---|
[1946] | 1479 | ///\endcode |
---|
[1749] | 1480 | void run(Node s) { |
---|
| 1481 | init(); |
---|
| 1482 | addSource(s); |
---|
| 1483 | start(); |
---|
| 1484 | } |
---|
[1981] | 1485 | |
---|
| 1486 | /// \brief Runs %DFSVisit algorithm to visit all nodes in the graph. |
---|
| 1487 | |
---|
| 1488 | /// This method runs the %DFS algorithm in order to |
---|
| 1489 | /// compute the %DFS path to each node. The algorithm computes |
---|
| 1490 | /// - The %DFS tree. |
---|
| 1491 | /// - The distance of each node from the root in the %DFS tree. |
---|
| 1492 | /// |
---|
| 1493 | ///\note d.run() is just a shortcut of the following code. |
---|
| 1494 | ///\code |
---|
| 1495 | /// d.init(); |
---|
| 1496 | /// for (NodeIt it(graph); it != INVALID; ++it) { |
---|
| 1497 | /// if (!d.reached(it)) { |
---|
| 1498 | /// d.addSource(it); |
---|
| 1499 | /// d.start(); |
---|
| 1500 | /// } |
---|
| 1501 | /// } |
---|
| 1502 | ///\endcode |
---|
| 1503 | void run() { |
---|
| 1504 | init(); |
---|
| 1505 | for (NodeIt it(*_graph); it != INVALID; ++it) { |
---|
| 1506 | if (!reached(it)) { |
---|
| 1507 | addSource(it); |
---|
| 1508 | start(); |
---|
| 1509 | } |
---|
| 1510 | } |
---|
| 1511 | } |
---|
[1749] | 1512 | ///@} |
---|
| 1513 | |
---|
| 1514 | /// \name Query Functions |
---|
| 1515 | /// The result of the %DFS algorithm can be obtained using these |
---|
| 1516 | /// functions.\n |
---|
| 1517 | /// Before the use of these functions, |
---|
| 1518 | /// either run() or start() must be called. |
---|
| 1519 | ///@{ |
---|
| 1520 | /// \brief Checks if a node is reachable from the root. |
---|
| 1521 | /// |
---|
| 1522 | /// Returns \c true if \c v is reachable from the root(s). |
---|
| 1523 | /// \warning The source nodes are inditated as unreachable. |
---|
| 1524 | /// \pre Either \ref run() or \ref start() |
---|
| 1525 | /// must be called before using this function. |
---|
| 1526 | /// |
---|
| 1527 | bool reached(Node v) { return (*_reached)[v]; } |
---|
| 1528 | ///@} |
---|
| 1529 | }; |
---|
| 1530 | |
---|
| 1531 | |
---|
[921] | 1532 | } //END OF NAMESPACE LEMON |
---|
[780] | 1533 | |
---|
| 1534 | #endif |
---|
| 1535 | |
---|