1 | /* -*- C++ -*- |
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2 | * lemon/topology.h - Part of LEMON, a generic C++ optimization library |
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3 | * |
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4 | * Copyright (C) 2006 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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5 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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6 | * |
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7 | * Permission to use, modify and distribute this software is granted |
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8 | * provided that this copyright notice appears in all copies. For |
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9 | * precise terms see the accompanying LICENSE file. |
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10 | * |
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11 | * This software is provided "AS IS" with no warranty of any kind, |
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12 | * express or implied, and with no claim as to its suitability for any |
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13 | * purpose. |
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14 | * |
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15 | */ |
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16 | |
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17 | #ifndef LEMON_TOPOLOGY_H |
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18 | #define LEMON_TOPOLOGY_H |
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19 | |
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20 | #include <lemon/dfs.h> |
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21 | #include <lemon/bfs.h> |
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22 | #include <lemon/graph_utils.h> |
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23 | #include <lemon/graph_adaptor.h> |
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24 | #include <lemon/maps.h> |
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25 | |
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26 | #include <lemon/concept/graph.h> |
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27 | #include <lemon/concept/ugraph.h> |
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28 | #include <lemon/concept_check.h> |
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29 | |
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30 | #include <lemon/bin_heap.h> |
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31 | #include <lemon/linear_heap.h> |
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32 | |
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33 | #include <stack> |
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34 | #include <functional> |
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35 | |
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36 | /// \ingroup topology |
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37 | /// \file |
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38 | /// \brief Topology related algorithms |
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39 | /// |
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40 | /// Topology related algorithms |
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41 | |
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42 | namespace lemon { |
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43 | |
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44 | /// \ingroup topology |
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45 | /// |
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46 | /// \brief Check that the given undirected graph is connected. |
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47 | /// |
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48 | /// Check that the given undirected graph connected. |
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49 | /// \param graph The undirected graph. |
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50 | /// \return %True when there is path between any two nodes in the graph. |
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51 | /// \note By definition, the empty graph is connected. |
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52 | template <typename UGraph> |
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53 | bool connected(const UGraph& graph) { |
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54 | checkConcept<concept::UGraph, UGraph>(); |
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55 | typedef typename UGraph::NodeIt NodeIt; |
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56 | if (NodeIt(graph) == INVALID) return true; |
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57 | Dfs<UGraph> dfs(graph); |
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58 | dfs.run(NodeIt(graph)); |
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59 | for (NodeIt it(graph); it != INVALID; ++it) { |
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60 | if (!dfs.reached(it)) { |
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61 | return false; |
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62 | } |
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63 | } |
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64 | return true; |
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65 | } |
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66 | |
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67 | /// \ingroup topology |
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68 | /// |
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69 | /// \brief Count the number of connected components of an undirected graph |
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70 | /// |
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71 | /// Count the number of connected components of an undirected graph |
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72 | /// |
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73 | /// \param graph The graph. It should be undirected. |
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74 | /// \return The number of components |
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75 | /// \note By definition, the empty graph consists |
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76 | /// of zero connected components. |
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77 | template <typename UGraph> |
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78 | int countConnectedComponents(const UGraph &graph) { |
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79 | checkConcept<concept::UGraph, UGraph>(); |
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80 | typedef typename UGraph::Node Node; |
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81 | typedef typename UGraph::Edge Edge; |
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82 | |
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83 | typedef NullMap<Node, Edge> PredMap; |
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84 | typedef NullMap<Node, int> DistMap; |
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85 | |
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86 | int compNum = 0; |
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87 | typename Bfs<UGraph>:: |
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88 | template DefPredMap<PredMap>:: |
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89 | template DefDistMap<DistMap>:: |
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90 | Create bfs(graph); |
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91 | |
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92 | PredMap predMap; |
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93 | bfs.predMap(predMap); |
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94 | |
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95 | DistMap distMap; |
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96 | bfs.distMap(distMap); |
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97 | |
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98 | bfs.init(); |
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99 | for(typename UGraph::NodeIt n(graph); n != INVALID; ++n) { |
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100 | if (!bfs.reached(n)) { |
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101 | bfs.addSource(n); |
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102 | bfs.start(); |
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103 | ++compNum; |
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104 | } |
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105 | } |
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106 | return compNum; |
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107 | } |
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108 | |
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109 | /// \ingroup topology |
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110 | /// |
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111 | /// \brief Find the connected components of an undirected graph |
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112 | /// |
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113 | /// Find the connected components of an undirected graph. |
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114 | /// |
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115 | /// \image html connected_components.png |
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116 | /// \image latex connected_components.eps "Connected components" width=\textwidth |
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117 | /// |
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118 | /// \param graph The graph. It should be undirected. |
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119 | /// \retval compMap A writable node map. The values will be set from 0 to |
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120 | /// the number of the connected components minus one. Each values of the map |
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121 | /// will be set exactly once, the values of a certain component will be |
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122 | /// set continuously. |
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123 | /// \return The number of components |
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124 | /// |
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125 | template <class UGraph, class NodeMap> |
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126 | int connectedComponents(const UGraph &graph, NodeMap &compMap) { |
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127 | checkConcept<concept::UGraph, UGraph>(); |
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128 | typedef typename UGraph::Node Node; |
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129 | typedef typename UGraph::Edge Edge; |
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130 | checkConcept<concept::WriteMap<Node, int>, NodeMap>(); |
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131 | |
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132 | typedef NullMap<Node, Edge> PredMap; |
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133 | typedef NullMap<Node, int> DistMap; |
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134 | |
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135 | int compNum = 0; |
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136 | typename Bfs<UGraph>:: |
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137 | template DefPredMap<PredMap>:: |
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138 | template DefDistMap<DistMap>:: |
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139 | Create bfs(graph); |
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140 | |
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141 | PredMap predMap; |
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142 | bfs.predMap(predMap); |
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143 | |
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144 | DistMap distMap; |
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145 | bfs.distMap(distMap); |
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146 | |
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147 | bfs.init(); |
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148 | for(typename UGraph::NodeIt n(graph); n != INVALID; ++n) { |
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149 | if(!bfs.reached(n)) { |
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150 | bfs.addSource(n); |
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151 | while (!bfs.emptyQueue()) { |
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152 | compMap.set(bfs.nextNode(), compNum); |
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153 | bfs.processNextNode(); |
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154 | } |
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155 | ++compNum; |
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156 | } |
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157 | } |
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158 | return compNum; |
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159 | } |
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160 | |
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161 | namespace _topology_bits { |
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162 | |
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163 | template <typename Graph, typename Iterator > |
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164 | struct LeaveOrderVisitor : public DfsVisitor<Graph> { |
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165 | public: |
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166 | typedef typename Graph::Node Node; |
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167 | LeaveOrderVisitor(Iterator it) : _it(it) {} |
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168 | |
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169 | void leave(const Node& node) { |
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170 | *(_it++) = node; |
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171 | } |
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172 | |
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173 | private: |
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174 | Iterator _it; |
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175 | }; |
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176 | |
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177 | template <typename Graph, typename Map> |
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178 | struct FillMapVisitor : public DfsVisitor<Graph> { |
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179 | public: |
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180 | typedef typename Graph::Node Node; |
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181 | typedef typename Map::Value Value; |
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182 | |
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183 | FillMapVisitor(Map& map, Value& value) |
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184 | : _map(map), _value(value) {} |
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185 | |
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186 | void reach(const Node& node) { |
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187 | _map.set(node, _value); |
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188 | } |
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189 | private: |
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190 | Map& _map; |
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191 | Value& _value; |
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192 | }; |
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193 | |
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194 | template <typename Graph, typename EdgeMap> |
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195 | struct StronglyConnectedCutEdgesVisitor : public DfsVisitor<Graph> { |
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196 | public: |
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197 | typedef typename Graph::Node Node; |
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198 | typedef typename Graph::Edge Edge; |
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199 | |
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200 | StronglyConnectedCutEdgesVisitor(const Graph& graph, EdgeMap& cutMap, |
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201 | int& cutNum) |
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202 | : _graph(graph), _cutMap(cutMap), _cutNum(cutNum), |
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203 | _compMap(graph), _num(0) { |
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204 | } |
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205 | |
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206 | void stop(const Node&) { |
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207 | ++_num; |
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208 | } |
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209 | |
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210 | void reach(const Node& node) { |
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211 | _compMap.set(node, _num); |
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212 | } |
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213 | |
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214 | void examine(const Edge& edge) { |
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215 | if (_compMap[_graph.source(edge)] != _compMap[_graph.target(edge)]) { |
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216 | _cutMap.set(edge, true); |
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217 | ++_cutNum; |
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218 | } |
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219 | } |
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220 | private: |
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221 | const Graph& _graph; |
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222 | EdgeMap& _cutMap; |
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223 | int& _cutNum; |
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224 | |
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225 | typename Graph::template NodeMap<int> _compMap; |
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226 | int _num; |
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227 | }; |
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228 | |
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229 | } |
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230 | |
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231 | |
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232 | /// \ingroup topology |
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233 | /// |
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234 | /// \brief Check that the given directed graph is strongly connected. |
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235 | /// |
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236 | /// Check that the given directed graph is strongly connected. The |
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237 | /// graph is strongly connected when any two nodes of the graph are |
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238 | /// connected with directed paths in both direction. |
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239 | /// \return %False when the graph is not strongly connected. |
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240 | /// \see connected |
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241 | /// |
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242 | /// \note By definition, the empty graph is strongly connected. |
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243 | template <typename Graph> |
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244 | bool stronglyConnected(const Graph& graph) { |
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245 | checkConcept<concept::StaticGraph, Graph>(); |
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246 | if (NodeIt(graph) == INVALID) return true; |
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247 | |
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248 | typedef typename Graph::Node Node; |
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249 | typedef typename Graph::NodeIt NodeIt; |
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250 | |
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251 | using namespace _topology_bits; |
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252 | |
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253 | typedef DfsVisitor<Graph> Visitor; |
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254 | Visitor visitor; |
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255 | |
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256 | DfsVisit<Graph, Visitor> dfs(graph, visitor); |
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257 | dfs.init(); |
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258 | dfs.addSource(NodeIt(graph)); |
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259 | dfs.start(); |
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260 | |
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261 | for (NodeIt it(graph); it != INVALID; ++it) { |
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262 | if (!dfs.reached(it)) { |
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263 | return false; |
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264 | } |
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265 | } |
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266 | |
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267 | typedef RevGraphAdaptor<const Graph> RGraph; |
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268 | RGraph rgraph(graph); |
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269 | |
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270 | typedef DfsVisitor<Graph> RVisitor; |
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271 | RVisitor rvisitor; |
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272 | |
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273 | DfsVisit<RGraph, RVisitor> rdfs(rgraph, rvisitor); |
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274 | rdfs.init(); |
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275 | rdfs.addSource(NodeIt(graph)); |
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276 | rdfs.start(); |
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277 | |
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278 | for (NodeIt it(graph); it != INVALID; ++it) { |
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279 | if (!rdfs.reached(it)) { |
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280 | return false; |
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281 | } |
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282 | } |
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283 | |
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284 | return true; |
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285 | } |
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286 | |
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287 | /// \ingroup topology |
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288 | /// |
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289 | /// \brief Count the strongly connected components of a directed graph |
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290 | /// |
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291 | /// Count the strongly connected components of a directed graph. |
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292 | /// The strongly connected components are the classes of an equivalence |
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293 | /// relation on the nodes of the graph. Two nodes are connected with |
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294 | /// directed paths in both direction. |
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295 | /// |
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296 | /// \param graph The graph. |
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297 | /// \return The number of components |
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298 | /// \note By definition, the empty graph has zero |
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299 | /// strongly connected components. |
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300 | template <typename Graph> |
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301 | int countStronglyConnectedComponents(const Graph& graph) { |
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302 | checkConcept<concept::StaticGraph, Graph>(); |
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303 | |
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304 | using namespace _topology_bits; |
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305 | |
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306 | typedef typename Graph::Node Node; |
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307 | typedef typename Graph::Edge Edge; |
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308 | typedef typename Graph::NodeIt NodeIt; |
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309 | typedef typename Graph::EdgeIt EdgeIt; |
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310 | |
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311 | typedef std::vector<Node> Container; |
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312 | typedef typename Container::iterator Iterator; |
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313 | |
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314 | Container nodes(countNodes(graph)); |
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315 | typedef LeaveOrderVisitor<Graph, Iterator> Visitor; |
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316 | Visitor visitor(nodes.begin()); |
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317 | |
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318 | DfsVisit<Graph, Visitor> dfs(graph, visitor); |
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319 | dfs.init(); |
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320 | for (NodeIt it(graph); it != INVALID; ++it) { |
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321 | if (!dfs.reached(it)) { |
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322 | dfs.addSource(it); |
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323 | dfs.start(); |
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324 | } |
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325 | } |
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326 | |
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327 | typedef typename Container::reverse_iterator RIterator; |
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328 | typedef RevGraphAdaptor<const Graph> RGraph; |
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329 | |
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330 | RGraph rgraph(graph); |
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331 | |
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332 | typedef DfsVisitor<Graph> RVisitor; |
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333 | RVisitor rvisitor; |
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334 | |
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335 | DfsVisit<RGraph, RVisitor> rdfs(rgraph, rvisitor); |
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336 | |
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337 | int compNum = 0; |
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338 | |
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339 | rdfs.init(); |
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340 | for (RIterator it = nodes.rbegin(); it != nodes.rend(); ++it) { |
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341 | if (!rdfs.reached(*it)) { |
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342 | rdfs.addSource(*it); |
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343 | rdfs.start(); |
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344 | ++compNum; |
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345 | } |
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346 | } |
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347 | return compNum; |
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348 | } |
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349 | |
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350 | /// \ingroup topology |
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351 | /// |
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352 | /// \brief Find the strongly connected components of a directed graph |
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353 | /// |
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354 | /// Find the strongly connected components of a directed graph. |
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355 | /// The strongly connected components are the classes of an equivalence |
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356 | /// relation on the nodes of the graph. Two nodes are in relationship |
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357 | /// when there are directed paths between them in both direction. |
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358 | /// |
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359 | /// \image html strongly_connected_components.png |
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360 | /// \image latex strongly_connected_components.eps "Strongly connected components" width=\textwidth |
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361 | /// |
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362 | /// \param graph The graph. |
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363 | /// \retval compMap A writable node map. The values will be set from 0 to |
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364 | /// the number of the strongly connected components minus one. Each values |
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365 | /// of the map will be set exactly once, the values of a certain component |
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366 | /// will be set continuously. |
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367 | /// \return The number of components |
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368 | /// |
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369 | template <typename Graph, typename NodeMap> |
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370 | int stronglyConnectedComponents(const Graph& graph, NodeMap& compMap) { |
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371 | checkConcept<concept::StaticGraph, Graph>(); |
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372 | typedef typename Graph::Node Node; |
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373 | typedef typename Graph::NodeIt NodeIt; |
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374 | checkConcept<concept::WriteMap<Node, int>, NodeMap>(); |
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375 | |
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376 | using namespace _topology_bits; |
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377 | |
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378 | typedef std::vector<Node> Container; |
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379 | typedef typename Container::iterator Iterator; |
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380 | |
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381 | Container nodes(countNodes(graph)); |
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382 | typedef LeaveOrderVisitor<Graph, Iterator> Visitor; |
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383 | Visitor visitor(nodes.begin()); |
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384 | |
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385 | DfsVisit<Graph, Visitor> dfs(graph, visitor); |
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386 | dfs.init(); |
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387 | for (NodeIt it(graph); it != INVALID; ++it) { |
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388 | if (!dfs.reached(it)) { |
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389 | dfs.addSource(it); |
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390 | dfs.start(); |
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391 | } |
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392 | } |
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393 | |
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394 | typedef typename Container::reverse_iterator RIterator; |
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395 | typedef RevGraphAdaptor<const Graph> RGraph; |
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396 | |
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397 | RGraph rgraph(graph); |
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398 | |
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399 | int compNum = 0; |
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400 | |
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401 | typedef FillMapVisitor<RGraph, NodeMap> RVisitor; |
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402 | RVisitor rvisitor(compMap, compNum); |
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403 | |
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404 | DfsVisit<RGraph, RVisitor> rdfs(rgraph, rvisitor); |
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405 | |
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406 | rdfs.init(); |
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407 | for (RIterator it = nodes.rbegin(); it != nodes.rend(); ++it) { |
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408 | if (!rdfs.reached(*it)) { |
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409 | rdfs.addSource(*it); |
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410 | rdfs.start(); |
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411 | ++compNum; |
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412 | } |
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413 | } |
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414 | return compNum; |
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415 | } |
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416 | |
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417 | /// \ingroup topology |
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418 | /// |
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419 | /// \brief Find the cut edges of the strongly connected components. |
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420 | /// |
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421 | /// Find the cut edges of the strongly connected components. |
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422 | /// The strongly connected components are the classes of an equivalence |
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423 | /// relation on the nodes of the graph. Two nodes are in relationship |
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424 | /// when there are directed paths between them in both direction. |
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425 | /// The strongly connected components are separated by the cut edges. |
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426 | /// |
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427 | /// \param graph The graph. |
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428 | /// \retval cutMap A writable node map. The values will be set true when the |
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429 | /// edge is a cut edge. |
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430 | /// |
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431 | /// \return The number of cut edges |
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432 | template <typename Graph, typename EdgeMap> |
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433 | int stronglyConnectedCutEdges(const Graph& graph, EdgeMap& cutMap) { |
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434 | checkConcept<concept::StaticGraph, Graph>(); |
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435 | typedef typename Graph::Node Node; |
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436 | typedef typename Graph::Edge Edge; |
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437 | typedef typename Graph::NodeIt NodeIt; |
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438 | checkConcept<concept::WriteMap<Edge, bool>, EdgeMap>(); |
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439 | |
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440 | using namespace _topology_bits; |
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441 | |
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442 | typedef std::vector<Node> Container; |
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443 | typedef typename Container::iterator Iterator; |
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444 | |
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445 | Container nodes(countNodes(graph)); |
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446 | typedef LeaveOrderVisitor<Graph, Iterator> Visitor; |
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447 | Visitor visitor(nodes.begin()); |
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448 | |
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449 | DfsVisit<Graph, Visitor> dfs(graph, visitor); |
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450 | dfs.init(); |
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451 | for (NodeIt it(graph); it != INVALID; ++it) { |
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452 | if (!dfs.reached(it)) { |
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453 | dfs.addSource(it); |
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454 | dfs.start(); |
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455 | } |
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456 | } |
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457 | |
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458 | typedef typename Container::reverse_iterator RIterator; |
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459 | typedef RevGraphAdaptor<const Graph> RGraph; |
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460 | |
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461 | RGraph rgraph(graph); |
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462 | |
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463 | int cutNum = 0; |
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464 | |
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465 | typedef StronglyConnectedCutEdgesVisitor<RGraph, EdgeMap> RVisitor; |
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466 | RVisitor rvisitor(rgraph, cutMap, cutNum); |
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467 | |
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468 | DfsVisit<RGraph, RVisitor> rdfs(rgraph, rvisitor); |
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469 | |
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470 | rdfs.init(); |
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471 | for (RIterator it = nodes.rbegin(); it != nodes.rend(); ++it) { |
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472 | if (!rdfs.reached(*it)) { |
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473 | rdfs.addSource(*it); |
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474 | rdfs.start(); |
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475 | } |
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476 | } |
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477 | return cutNum; |
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478 | } |
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479 | |
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480 | namespace _topology_bits { |
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481 | |
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482 | template <typename Graph> |
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483 | class CountBiNodeConnectedComponentsVisitor : public DfsVisitor<Graph> { |
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484 | public: |
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485 | typedef typename Graph::Node Node; |
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486 | typedef typename Graph::Edge Edge; |
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487 | typedef typename Graph::UEdge UEdge; |
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488 | |
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489 | CountBiNodeConnectedComponentsVisitor(const Graph& graph, int &compNum) |
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490 | : _graph(graph), _compNum(compNum), |
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491 | _numMap(graph), _retMap(graph), _predMap(graph), _num(0) {} |
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492 | |
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493 | void start(const Node& node) { |
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494 | _predMap.set(node, INVALID); |
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495 | } |
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496 | |
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497 | void reach(const Node& node) { |
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498 | _numMap.set(node, _num); |
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499 | _retMap.set(node, _num); |
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500 | ++_num; |
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501 | } |
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502 | |
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503 | void discover(const Edge& edge) { |
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504 | _predMap.set(_graph.target(edge), _graph.source(edge)); |
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505 | } |
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506 | |
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507 | void examine(const Edge& edge) { |
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508 | if (_graph.source(edge) == _graph.target(edge) && |
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509 | _graph.direction(edge)) { |
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510 | ++_compNum; |
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511 | return; |
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512 | } |
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513 | if (_predMap[_graph.source(edge)] == _graph.target(edge)) { |
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514 | return; |
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515 | } |
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516 | if (_retMap[_graph.source(edge)] > _numMap[_graph.target(edge)]) { |
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517 | _retMap.set(_graph.source(edge), _numMap[_graph.target(edge)]); |
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518 | } |
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519 | } |
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520 | |
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521 | void backtrack(const Edge& edge) { |
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522 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
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523 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
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524 | } |
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525 | if (_numMap[_graph.source(edge)] <= _retMap[_graph.target(edge)]) { |
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526 | ++_compNum; |
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527 | } |
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528 | } |
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529 | |
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530 | private: |
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531 | const Graph& _graph; |
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532 | int& _compNum; |
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533 | |
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534 | typename Graph::template NodeMap<int> _numMap; |
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535 | typename Graph::template NodeMap<int> _retMap; |
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536 | typename Graph::template NodeMap<Node> _predMap; |
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537 | int _num; |
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538 | }; |
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539 | |
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540 | template <typename Graph, typename EdgeMap> |
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541 | class BiNodeConnectedComponentsVisitor : public DfsVisitor<Graph> { |
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542 | public: |
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543 | typedef typename Graph::Node Node; |
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544 | typedef typename Graph::Edge Edge; |
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545 | typedef typename Graph::UEdge UEdge; |
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546 | |
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547 | BiNodeConnectedComponentsVisitor(const Graph& graph, |
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548 | EdgeMap& compMap, int &compNum) |
---|
549 | : _graph(graph), _compMap(compMap), _compNum(compNum), |
---|
550 | _numMap(graph), _retMap(graph), _predMap(graph), _num(0) {} |
---|
551 | |
---|
552 | void start(const Node& node) { |
---|
553 | _predMap.set(node, INVALID); |
---|
554 | } |
---|
555 | |
---|
556 | void reach(const Node& node) { |
---|
557 | _numMap.set(node, _num); |
---|
558 | _retMap.set(node, _num); |
---|
559 | ++_num; |
---|
560 | } |
---|
561 | |
---|
562 | void discover(const Edge& edge) { |
---|
563 | Node target = _graph.target(edge); |
---|
564 | _predMap.set(target, edge); |
---|
565 | _edgeStack.push(edge); |
---|
566 | } |
---|
567 | |
---|
568 | void examine(const Edge& edge) { |
---|
569 | Node source = _graph.source(edge); |
---|
570 | Node target = _graph.target(edge); |
---|
571 | if (source == target && _graph.direction(edge)) { |
---|
572 | _compMap.set(edge, _compNum); |
---|
573 | ++_compNum; |
---|
574 | return; |
---|
575 | } |
---|
576 | if (_numMap[target] < _numMap[source]) { |
---|
577 | if (_predMap[source] != _graph.oppositeEdge(edge)) { |
---|
578 | _edgeStack.push(edge); |
---|
579 | } |
---|
580 | } |
---|
581 | if (_predMap[source] != INVALID && |
---|
582 | target == _graph.source(_predMap[source])) { |
---|
583 | return; |
---|
584 | } |
---|
585 | if (_retMap[source] > _numMap[target]) { |
---|
586 | _retMap.set(source, _numMap[target]); |
---|
587 | } |
---|
588 | } |
---|
589 | |
---|
590 | void backtrack(const Edge& edge) { |
---|
591 | Node source = _graph.source(edge); |
---|
592 | Node target = _graph.target(edge); |
---|
593 | if (_retMap[source] > _retMap[target]) { |
---|
594 | _retMap.set(source, _retMap[target]); |
---|
595 | } |
---|
596 | if (_numMap[source] <= _retMap[target]) { |
---|
597 | while (_edgeStack.top() != edge) { |
---|
598 | _compMap.set(_edgeStack.top(), _compNum); |
---|
599 | _edgeStack.pop(); |
---|
600 | } |
---|
601 | _compMap.set(edge, _compNum); |
---|
602 | _edgeStack.pop(); |
---|
603 | ++_compNum; |
---|
604 | } |
---|
605 | } |
---|
606 | |
---|
607 | private: |
---|
608 | const Graph& _graph; |
---|
609 | EdgeMap& _compMap; |
---|
610 | int& _compNum; |
---|
611 | |
---|
612 | typename Graph::template NodeMap<int> _numMap; |
---|
613 | typename Graph::template NodeMap<int> _retMap; |
---|
614 | typename Graph::template NodeMap<Edge> _predMap; |
---|
615 | std::stack<UEdge> _edgeStack; |
---|
616 | int _num; |
---|
617 | }; |
---|
618 | |
---|
619 | |
---|
620 | template <typename Graph, typename NodeMap> |
---|
621 | class BiNodeConnectedCutNodesVisitor : public DfsVisitor<Graph> { |
---|
622 | public: |
---|
623 | typedef typename Graph::Node Node; |
---|
624 | typedef typename Graph::Edge Edge; |
---|
625 | typedef typename Graph::UEdge UEdge; |
---|
626 | |
---|
627 | BiNodeConnectedCutNodesVisitor(const Graph& graph, NodeMap& cutMap, |
---|
628 | int& cutNum) |
---|
629 | : _graph(graph), _cutMap(cutMap), _cutNum(cutNum), |
---|
630 | _numMap(graph), _retMap(graph), _predMap(graph), _num(0) {} |
---|
631 | |
---|
632 | void start(const Node& node) { |
---|
633 | _predMap.set(node, INVALID); |
---|
634 | rootCut = false; |
---|
635 | } |
---|
636 | |
---|
637 | void reach(const Node& node) { |
---|
638 | _numMap.set(node, _num); |
---|
639 | _retMap.set(node, _num); |
---|
640 | ++_num; |
---|
641 | } |
---|
642 | |
---|
643 | void discover(const Edge& edge) { |
---|
644 | _predMap.set(_graph.target(edge), _graph.source(edge)); |
---|
645 | } |
---|
646 | |
---|
647 | void examine(const Edge& edge) { |
---|
648 | if (_graph.source(edge) == _graph.target(edge) && |
---|
649 | _graph.direction(edge)) { |
---|
650 | if (!_cutMap[_graph.source(edge)]) { |
---|
651 | _cutMap.set(_graph.source(edge), true); |
---|
652 | ++_cutNum; |
---|
653 | } |
---|
654 | return; |
---|
655 | } |
---|
656 | if (_predMap[_graph.source(edge)] == _graph.target(edge)) return; |
---|
657 | if (_retMap[_graph.source(edge)] > _numMap[_graph.target(edge)]) { |
---|
658 | _retMap.set(_graph.source(edge), _numMap[_graph.target(edge)]); |
---|
659 | } |
---|
660 | } |
---|
661 | |
---|
662 | void backtrack(const Edge& edge) { |
---|
663 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
664 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
665 | } |
---|
666 | if (_numMap[_graph.source(edge)] <= _retMap[_graph.target(edge)]) { |
---|
667 | if (_predMap[_graph.source(edge)] != INVALID) { |
---|
668 | if (!_cutMap[_graph.source(edge)]) { |
---|
669 | _cutMap.set(_graph.source(edge), true); |
---|
670 | ++_cutNum; |
---|
671 | } |
---|
672 | } else if (rootCut) { |
---|
673 | if (!_cutMap[_graph.source(edge)]) { |
---|
674 | _cutMap.set(_graph.source(edge), true); |
---|
675 | ++_cutNum; |
---|
676 | } |
---|
677 | } else { |
---|
678 | rootCut = true; |
---|
679 | } |
---|
680 | } |
---|
681 | } |
---|
682 | |
---|
683 | private: |
---|
684 | const Graph& _graph; |
---|
685 | NodeMap& _cutMap; |
---|
686 | int& _cutNum; |
---|
687 | |
---|
688 | typename Graph::template NodeMap<int> _numMap; |
---|
689 | typename Graph::template NodeMap<int> _retMap; |
---|
690 | typename Graph::template NodeMap<Node> _predMap; |
---|
691 | std::stack<UEdge> _edgeStack; |
---|
692 | int _num; |
---|
693 | bool rootCut; |
---|
694 | }; |
---|
695 | |
---|
696 | } |
---|
697 | |
---|
698 | template <typename UGraph> |
---|
699 | int countBiNodeConnectedComponents(const UGraph& graph); |
---|
700 | |
---|
701 | /// \ingroup topology |
---|
702 | /// |
---|
703 | /// \brief Checks the graph is bi-node-connected. |
---|
704 | /// |
---|
705 | /// This function checks that the undirected graph is bi-node-connected |
---|
706 | /// graph. The graph is bi-node-connected if any two undirected edge is |
---|
707 | /// on same circle. |
---|
708 | /// |
---|
709 | /// \param graph The graph. |
---|
710 | /// \return %True when the graph bi-node-connected. |
---|
711 | /// \todo Make it faster. |
---|
712 | template <typename UGraph> |
---|
713 | bool biNodeConnected(const UGraph& graph) { |
---|
714 | return countBiNodeConnectedComponents(graph) == 1; |
---|
715 | } |
---|
716 | |
---|
717 | /// \ingroup topology |
---|
718 | /// |
---|
719 | /// \brief Count the biconnected components. |
---|
720 | /// |
---|
721 | /// This function finds the bi-node-connected components in an undirected |
---|
722 | /// graph. The biconnected components are the classes of an equivalence |
---|
723 | /// relation on the undirected edges. Two undirected edge is in relationship |
---|
724 | /// when they are on same circle. |
---|
725 | /// |
---|
726 | /// \param graph The graph. |
---|
727 | /// \return The number of components. |
---|
728 | template <typename UGraph> |
---|
729 | int countBiNodeConnectedComponents(const UGraph& graph) { |
---|
730 | checkConcept<concept::UGraph, UGraph>(); |
---|
731 | typedef typename UGraph::NodeIt NodeIt; |
---|
732 | |
---|
733 | using namespace _topology_bits; |
---|
734 | |
---|
735 | typedef CountBiNodeConnectedComponentsVisitor<UGraph> Visitor; |
---|
736 | |
---|
737 | int compNum = 0; |
---|
738 | Visitor visitor(graph, compNum); |
---|
739 | |
---|
740 | DfsVisit<UGraph, Visitor> dfs(graph, visitor); |
---|
741 | dfs.init(); |
---|
742 | |
---|
743 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
744 | if (!dfs.reached(it)) { |
---|
745 | dfs.addSource(it); |
---|
746 | dfs.start(); |
---|
747 | } |
---|
748 | } |
---|
749 | return compNum; |
---|
750 | } |
---|
751 | |
---|
752 | /// \ingroup topology |
---|
753 | /// |
---|
754 | /// \brief Find the bi-node-connected components. |
---|
755 | /// |
---|
756 | /// This function finds the bi-node-connected components in an undirected |
---|
757 | /// graph. The bi-node-connected components are the classes of an equivalence |
---|
758 | /// relation on the undirected edges. Two undirected edge are in relationship |
---|
759 | /// when they are on same circle. |
---|
760 | /// |
---|
761 | /// \image html node_biconnected_components.png |
---|
762 | /// \image latex node_biconnected_components.eps "bi-node-connected components" width=\textwidth |
---|
763 | /// |
---|
764 | /// \param graph The graph. |
---|
765 | /// \retval compMap A writable uedge map. The values will be set from 0 |
---|
766 | /// to the number of the biconnected components minus one. Each values |
---|
767 | /// of the map will be set exactly once, the values of a certain component |
---|
768 | /// will be set continuously. |
---|
769 | /// \return The number of components. |
---|
770 | /// |
---|
771 | template <typename UGraph, typename UEdgeMap> |
---|
772 | int biNodeConnectedComponents(const UGraph& graph, |
---|
773 | UEdgeMap& compMap) { |
---|
774 | checkConcept<concept::UGraph, UGraph>(); |
---|
775 | typedef typename UGraph::NodeIt NodeIt; |
---|
776 | typedef typename UGraph::UEdge UEdge; |
---|
777 | checkConcept<concept::WriteMap<UEdge, int>, UEdgeMap>(); |
---|
778 | |
---|
779 | using namespace _topology_bits; |
---|
780 | |
---|
781 | typedef BiNodeConnectedComponentsVisitor<UGraph, UEdgeMap> Visitor; |
---|
782 | |
---|
783 | int compNum = 0; |
---|
784 | Visitor visitor(graph, compMap, compNum); |
---|
785 | |
---|
786 | DfsVisit<UGraph, Visitor> dfs(graph, visitor); |
---|
787 | dfs.init(); |
---|
788 | |
---|
789 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
790 | if (!dfs.reached(it)) { |
---|
791 | dfs.addSource(it); |
---|
792 | dfs.start(); |
---|
793 | } |
---|
794 | } |
---|
795 | return compNum; |
---|
796 | } |
---|
797 | |
---|
798 | /// \ingroup topology |
---|
799 | /// |
---|
800 | /// \brief Find the bi-node-connected cut nodes. |
---|
801 | /// |
---|
802 | /// This function finds the bi-node-connected cut nodes in an undirected |
---|
803 | /// graph. The bi-node-connected components are the classes of an equivalence |
---|
804 | /// relation on the undirected edges. Two undirected edges are in |
---|
805 | /// relationship when they are on same circle. The biconnected components |
---|
806 | /// are separted by nodes which are the cut nodes of the components. |
---|
807 | /// |
---|
808 | /// \param graph The graph. |
---|
809 | /// \retval cutMap A writable edge map. The values will be set true when |
---|
810 | /// the node separate two or more components. |
---|
811 | /// \return The number of the cut nodes. |
---|
812 | template <typename UGraph, typename NodeMap> |
---|
813 | int biNodeConnectedCutNodes(const UGraph& graph, NodeMap& cutMap) { |
---|
814 | checkConcept<concept::UGraph, UGraph>(); |
---|
815 | typedef typename UGraph::Node Node; |
---|
816 | typedef typename UGraph::NodeIt NodeIt; |
---|
817 | checkConcept<concept::WriteMap<Node, bool>, NodeMap>(); |
---|
818 | |
---|
819 | using namespace _topology_bits; |
---|
820 | |
---|
821 | typedef BiNodeConnectedCutNodesVisitor<UGraph, NodeMap> Visitor; |
---|
822 | |
---|
823 | int cutNum = 0; |
---|
824 | Visitor visitor(graph, cutMap, cutNum); |
---|
825 | |
---|
826 | DfsVisit<UGraph, Visitor> dfs(graph, visitor); |
---|
827 | dfs.init(); |
---|
828 | |
---|
829 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
830 | if (!dfs.reached(it)) { |
---|
831 | dfs.addSource(it); |
---|
832 | dfs.start(); |
---|
833 | } |
---|
834 | } |
---|
835 | return cutNum; |
---|
836 | } |
---|
837 | |
---|
838 | namespace _topology_bits { |
---|
839 | |
---|
840 | template <typename Graph> |
---|
841 | class CountBiEdgeConnectedComponentsVisitor : public DfsVisitor<Graph> { |
---|
842 | public: |
---|
843 | typedef typename Graph::Node Node; |
---|
844 | typedef typename Graph::Edge Edge; |
---|
845 | typedef typename Graph::UEdge UEdge; |
---|
846 | |
---|
847 | CountBiEdgeConnectedComponentsVisitor(const Graph& graph, int &compNum) |
---|
848 | : _graph(graph), _compNum(compNum), |
---|
849 | _numMap(graph), _retMap(graph), _predMap(graph), _num(0) {} |
---|
850 | |
---|
851 | void start(const Node& node) { |
---|
852 | _predMap.set(node, INVALID); |
---|
853 | } |
---|
854 | |
---|
855 | void reach(const Node& node) { |
---|
856 | _numMap.set(node, _num); |
---|
857 | _retMap.set(node, _num); |
---|
858 | ++_num; |
---|
859 | } |
---|
860 | |
---|
861 | void leave(const Node& node) { |
---|
862 | if (_numMap[node] <= _retMap[node]) { |
---|
863 | ++_compNum; |
---|
864 | } |
---|
865 | } |
---|
866 | |
---|
867 | void discover(const Edge& edge) { |
---|
868 | _predMap.set(_graph.target(edge), edge); |
---|
869 | } |
---|
870 | |
---|
871 | void examine(const Edge& edge) { |
---|
872 | if (_predMap[_graph.source(edge)] == _graph.oppositeEdge(edge)) { |
---|
873 | return; |
---|
874 | } |
---|
875 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
876 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
877 | } |
---|
878 | } |
---|
879 | |
---|
880 | void backtrack(const Edge& edge) { |
---|
881 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
882 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
883 | } |
---|
884 | } |
---|
885 | |
---|
886 | private: |
---|
887 | const Graph& _graph; |
---|
888 | int& _compNum; |
---|
889 | |
---|
890 | typename Graph::template NodeMap<int> _numMap; |
---|
891 | typename Graph::template NodeMap<int> _retMap; |
---|
892 | typename Graph::template NodeMap<Edge> _predMap; |
---|
893 | int _num; |
---|
894 | }; |
---|
895 | |
---|
896 | template <typename Graph, typename NodeMap> |
---|
897 | class BiEdgeConnectedComponentsVisitor : public DfsVisitor<Graph> { |
---|
898 | public: |
---|
899 | typedef typename Graph::Node Node; |
---|
900 | typedef typename Graph::Edge Edge; |
---|
901 | typedef typename Graph::UEdge UEdge; |
---|
902 | |
---|
903 | BiEdgeConnectedComponentsVisitor(const Graph& graph, |
---|
904 | NodeMap& compMap, int &compNum) |
---|
905 | : _graph(graph), _compMap(compMap), _compNum(compNum), |
---|
906 | _numMap(graph), _retMap(graph), _predMap(graph), _num(0) {} |
---|
907 | |
---|
908 | void start(const Node& node) { |
---|
909 | _predMap.set(node, INVALID); |
---|
910 | } |
---|
911 | |
---|
912 | void reach(const Node& node) { |
---|
913 | _numMap.set(node, _num); |
---|
914 | _retMap.set(node, _num); |
---|
915 | _nodeStack.push(node); |
---|
916 | ++_num; |
---|
917 | } |
---|
918 | |
---|
919 | void leave(const Node& node) { |
---|
920 | if (_numMap[node] <= _retMap[node]) { |
---|
921 | while (_nodeStack.top() != node) { |
---|
922 | _compMap.set(_nodeStack.top(), _compNum); |
---|
923 | _nodeStack.pop(); |
---|
924 | } |
---|
925 | _compMap.set(node, _compNum); |
---|
926 | _nodeStack.pop(); |
---|
927 | ++_compNum; |
---|
928 | } |
---|
929 | } |
---|
930 | |
---|
931 | void discover(const Edge& edge) { |
---|
932 | _predMap.set(_graph.target(edge), edge); |
---|
933 | } |
---|
934 | |
---|
935 | void examine(const Edge& edge) { |
---|
936 | if (_predMap[_graph.source(edge)] == _graph.oppositeEdge(edge)) { |
---|
937 | return; |
---|
938 | } |
---|
939 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
940 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
941 | } |
---|
942 | } |
---|
943 | |
---|
944 | void backtrack(const Edge& edge) { |
---|
945 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
946 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
947 | } |
---|
948 | } |
---|
949 | |
---|
950 | private: |
---|
951 | const Graph& _graph; |
---|
952 | NodeMap& _compMap; |
---|
953 | int& _compNum; |
---|
954 | |
---|
955 | typename Graph::template NodeMap<int> _numMap; |
---|
956 | typename Graph::template NodeMap<int> _retMap; |
---|
957 | typename Graph::template NodeMap<Edge> _predMap; |
---|
958 | std::stack<Node> _nodeStack; |
---|
959 | int _num; |
---|
960 | }; |
---|
961 | |
---|
962 | |
---|
963 | template <typename Graph, typename EdgeMap> |
---|
964 | class BiEdgeConnectedCutEdgesVisitor : public DfsVisitor<Graph> { |
---|
965 | public: |
---|
966 | typedef typename Graph::Node Node; |
---|
967 | typedef typename Graph::Edge Edge; |
---|
968 | typedef typename Graph::UEdge UEdge; |
---|
969 | |
---|
970 | BiEdgeConnectedCutEdgesVisitor(const Graph& graph, |
---|
971 | EdgeMap& cutMap, int &cutNum) |
---|
972 | : _graph(graph), _cutMap(cutMap), _cutNum(cutNum), |
---|
973 | _numMap(graph), _retMap(graph), _predMap(graph), _num(0) {} |
---|
974 | |
---|
975 | void start(const Node& node) { |
---|
976 | _predMap[node] = INVALID; |
---|
977 | } |
---|
978 | |
---|
979 | void reach(const Node& node) { |
---|
980 | _numMap.set(node, _num); |
---|
981 | _retMap.set(node, _num); |
---|
982 | ++_num; |
---|
983 | } |
---|
984 | |
---|
985 | void leave(const Node& node) { |
---|
986 | if (_numMap[node] <= _retMap[node]) { |
---|
987 | if (_predMap[node] != INVALID) { |
---|
988 | _cutMap.set(_predMap[node], true); |
---|
989 | ++_cutNum; |
---|
990 | } |
---|
991 | } |
---|
992 | } |
---|
993 | |
---|
994 | void discover(const Edge& edge) { |
---|
995 | _predMap.set(_graph.target(edge), edge); |
---|
996 | } |
---|
997 | |
---|
998 | void examine(const Edge& edge) { |
---|
999 | if (_predMap[_graph.source(edge)] == _graph.oppositeEdge(edge)) { |
---|
1000 | return; |
---|
1001 | } |
---|
1002 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
1003 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
1004 | } |
---|
1005 | } |
---|
1006 | |
---|
1007 | void backtrack(const Edge& edge) { |
---|
1008 | if (_retMap[_graph.source(edge)] > _retMap[_graph.target(edge)]) { |
---|
1009 | _retMap.set(_graph.source(edge), _retMap[_graph.target(edge)]); |
---|
1010 | } |
---|
1011 | } |
---|
1012 | |
---|
1013 | private: |
---|
1014 | const Graph& _graph; |
---|
1015 | EdgeMap& _cutMap; |
---|
1016 | int& _cutNum; |
---|
1017 | |
---|
1018 | typename Graph::template NodeMap<int> _numMap; |
---|
1019 | typename Graph::template NodeMap<int> _retMap; |
---|
1020 | typename Graph::template NodeMap<Edge> _predMap; |
---|
1021 | int _num; |
---|
1022 | }; |
---|
1023 | } |
---|
1024 | |
---|
1025 | template <typename UGraph> |
---|
1026 | int countbiEdgeConnectedComponents(const UGraph& graph); |
---|
1027 | |
---|
1028 | /// \ingroup topology |
---|
1029 | /// |
---|
1030 | /// \brief Checks that the graph is bi-edge-connected. |
---|
1031 | /// |
---|
1032 | /// This function checks that the graph is bi-edge-connected. The undirected |
---|
1033 | /// graph is bi-edge-connected when any two nodes are connected with two |
---|
1034 | /// edge-disjoint paths. |
---|
1035 | /// |
---|
1036 | /// \param graph The undirected graph. |
---|
1037 | /// \return The number of components. |
---|
1038 | /// \todo Make it faster. |
---|
1039 | template <typename UGraph> |
---|
1040 | bool biEdgeConnected(const UGraph& graph) { |
---|
1041 | return countBiEdgeConnectedComponents(graph) == 1; |
---|
1042 | } |
---|
1043 | |
---|
1044 | /// \ingroup topology |
---|
1045 | /// |
---|
1046 | /// \brief Count the bi-edge-connected components. |
---|
1047 | /// |
---|
1048 | /// This function count the bi-edge-connected components in an undirected |
---|
1049 | /// graph. The bi-edge-connected components are the classes of an equivalence |
---|
1050 | /// relation on the nodes. Two nodes are in relationship when they are |
---|
1051 | /// connected with at least two edge-disjoint paths. |
---|
1052 | /// |
---|
1053 | /// \param graph The undirected graph. |
---|
1054 | /// \return The number of components. |
---|
1055 | template <typename UGraph> |
---|
1056 | int countBiEdgeConnectedComponents(const UGraph& graph) { |
---|
1057 | checkConcept<concept::UGraph, UGraph>(); |
---|
1058 | typedef typename UGraph::NodeIt NodeIt; |
---|
1059 | |
---|
1060 | using namespace _topology_bits; |
---|
1061 | |
---|
1062 | typedef CountBiEdgeConnectedComponentsVisitor<UGraph> Visitor; |
---|
1063 | |
---|
1064 | int compNum = 0; |
---|
1065 | Visitor visitor(graph, compNum); |
---|
1066 | |
---|
1067 | DfsVisit<UGraph, Visitor> dfs(graph, visitor); |
---|
1068 | dfs.init(); |
---|
1069 | |
---|
1070 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1071 | if (!dfs.reached(it)) { |
---|
1072 | dfs.addSource(it); |
---|
1073 | dfs.start(); |
---|
1074 | } |
---|
1075 | } |
---|
1076 | return compNum; |
---|
1077 | } |
---|
1078 | |
---|
1079 | /// \ingroup topology |
---|
1080 | /// |
---|
1081 | /// \brief Find the bi-edge-connected components. |
---|
1082 | /// |
---|
1083 | /// This function finds the bi-edge-connected components in an undirected |
---|
1084 | /// graph. The bi-edge-connected components are the classes of an equivalence |
---|
1085 | /// relation on the nodes. Two nodes are in relationship when they are |
---|
1086 | /// connected at least two edge-disjoint paths. |
---|
1087 | /// |
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1088 | /// \image html edge_biconnected_components.png |
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1089 | /// \image latex edge_biconnected_components.eps "bi-edge-connected components" width=\textwidth |
---|
1090 | /// |
---|
1091 | /// \param graph The graph. |
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1092 | /// \retval compMap A writable node map. The values will be set from 0 to |
---|
1093 | /// the number of the biconnected components minus one. Each values |
---|
1094 | /// of the map will be set exactly once, the values of a certain component |
---|
1095 | /// will be set continuously. |
---|
1096 | /// \return The number of components. |
---|
1097 | /// |
---|
1098 | template <typename UGraph, typename NodeMap> |
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1099 | int biEdgeConnectedComponents(const UGraph& graph, NodeMap& compMap) { |
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1100 | checkConcept<concept::UGraph, UGraph>(); |
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1101 | typedef typename UGraph::NodeIt NodeIt; |
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1102 | typedef typename UGraph::Node Node; |
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1103 | checkConcept<concept::WriteMap<Node, int>, NodeMap>(); |
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1104 | |
---|
1105 | using namespace _topology_bits; |
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1106 | |
---|
1107 | typedef BiEdgeConnectedComponentsVisitor<UGraph, NodeMap> Visitor; |
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1108 | |
---|
1109 | int compNum = 0; |
---|
1110 | Visitor visitor(graph, compMap, compNum); |
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1111 | |
---|
1112 | DfsVisit<UGraph, Visitor> dfs(graph, visitor); |
---|
1113 | dfs.init(); |
---|
1114 | |
---|
1115 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1116 | if (!dfs.reached(it)) { |
---|
1117 | dfs.addSource(it); |
---|
1118 | dfs.start(); |
---|
1119 | } |
---|
1120 | } |
---|
1121 | return compNum; |
---|
1122 | } |
---|
1123 | |
---|
1124 | /// \ingroup topology |
---|
1125 | /// |
---|
1126 | /// \brief Find the bi-edge-connected cut edges. |
---|
1127 | /// |
---|
1128 | /// This function finds the bi-edge-connected components in an undirected |
---|
1129 | /// graph. The bi-edge-connected components are the classes of an equivalence |
---|
1130 | /// relation on the nodes. Two nodes are in relationship when they are |
---|
1131 | /// connected with at least two edge-disjoint paths. The bi-edge-connected |
---|
1132 | /// components are separted by edges which are the cut edges of the |
---|
1133 | /// components. |
---|
1134 | /// |
---|
1135 | /// \param graph The graph. |
---|
1136 | /// \retval cutMap A writable node map. The values will be set true when the |
---|
1137 | /// edge is a cut edge. |
---|
1138 | /// \return The number of cut edges. |
---|
1139 | template <typename UGraph, typename UEdgeMap> |
---|
1140 | int biEdgeConnectedCutEdges(const UGraph& graph, UEdgeMap& cutMap) { |
---|
1141 | checkConcept<concept::UGraph, UGraph>(); |
---|
1142 | typedef typename UGraph::NodeIt NodeIt; |
---|
1143 | typedef typename UGraph::UEdge UEdge; |
---|
1144 | checkConcept<concept::WriteMap<UEdge, bool>, UEdgeMap>(); |
---|
1145 | |
---|
1146 | using namespace _topology_bits; |
---|
1147 | |
---|
1148 | typedef BiEdgeConnectedCutEdgesVisitor<UGraph, UEdgeMap> Visitor; |
---|
1149 | |
---|
1150 | int cutNum = 0; |
---|
1151 | Visitor visitor(graph, cutMap, cutNum); |
---|
1152 | |
---|
1153 | DfsVisit<UGraph, Visitor> dfs(graph, visitor); |
---|
1154 | dfs.init(); |
---|
1155 | |
---|
1156 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1157 | if (!dfs.reached(it)) { |
---|
1158 | dfs.addSource(it); |
---|
1159 | dfs.start(); |
---|
1160 | } |
---|
1161 | } |
---|
1162 | return cutNum; |
---|
1163 | } |
---|
1164 | |
---|
1165 | |
---|
1166 | namespace _topology_bits { |
---|
1167 | |
---|
1168 | template <typename Graph, typename IntNodeMap> |
---|
1169 | class TopologicalSortVisitor : public DfsVisitor<Graph> { |
---|
1170 | public: |
---|
1171 | typedef typename Graph::Node Node; |
---|
1172 | typedef typename Graph::Edge edge; |
---|
1173 | |
---|
1174 | TopologicalSortVisitor(IntNodeMap& order, int num) |
---|
1175 | : _order(order), _num(num) {} |
---|
1176 | |
---|
1177 | void leave(const Node& node) { |
---|
1178 | _order.set(node, --_num); |
---|
1179 | } |
---|
1180 | |
---|
1181 | private: |
---|
1182 | IntNodeMap& _order; |
---|
1183 | int _num; |
---|
1184 | }; |
---|
1185 | |
---|
1186 | } |
---|
1187 | |
---|
1188 | /// \ingroup topology |
---|
1189 | /// |
---|
1190 | /// \brief Sort the nodes of a DAG into topolgical order. |
---|
1191 | /// |
---|
1192 | /// Sort the nodes of a DAG into topolgical order. |
---|
1193 | /// |
---|
1194 | /// \param graph The graph. It should be directed and acyclic. |
---|
1195 | /// \retval order A writable node map. The values will be set from 0 to |
---|
1196 | /// the number of the nodes in the graph minus one. Each values of the map |
---|
1197 | /// will be set exactly once, the values will be set descending order. |
---|
1198 | /// |
---|
1199 | /// \see checkedTopologicalSort |
---|
1200 | /// \see dag |
---|
1201 | template <typename Graph, typename NodeMap> |
---|
1202 | void topologicalSort(const Graph& graph, NodeMap& order) { |
---|
1203 | using namespace _topology_bits; |
---|
1204 | |
---|
1205 | checkConcept<concept::StaticGraph, Graph>(); |
---|
1206 | checkConcept<concept::WriteMap<typename Graph::Node, int>, NodeMap>(); |
---|
1207 | |
---|
1208 | typedef typename Graph::Node Node; |
---|
1209 | typedef typename Graph::NodeIt NodeIt; |
---|
1210 | typedef typename Graph::Edge Edge; |
---|
1211 | |
---|
1212 | TopologicalSortVisitor<Graph, NodeMap> |
---|
1213 | visitor(order, countNodes(graph)); |
---|
1214 | |
---|
1215 | DfsVisit<Graph, TopologicalSortVisitor<Graph, NodeMap> > |
---|
1216 | dfs(graph, visitor); |
---|
1217 | |
---|
1218 | dfs.init(); |
---|
1219 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1220 | if (!dfs.reached(it)) { |
---|
1221 | dfs.addSource(it); |
---|
1222 | dfs.start(); |
---|
1223 | } |
---|
1224 | } |
---|
1225 | } |
---|
1226 | |
---|
1227 | /// \ingroup topology |
---|
1228 | /// |
---|
1229 | /// \brief Sort the nodes of a DAG into topolgical order. |
---|
1230 | /// |
---|
1231 | /// Sort the nodes of a DAG into topolgical order. It also checks |
---|
1232 | /// that the given graph is DAG. |
---|
1233 | /// |
---|
1234 | /// \param graph The graph. It should be directed and acyclic. |
---|
1235 | /// \retval order A readable - writable node map. The values will be set |
---|
1236 | /// from 0 to the number of the nodes in the graph minus one. Each values |
---|
1237 | /// of the map will be set exactly once, the values will be set descending |
---|
1238 | /// order. |
---|
1239 | /// \return %False when the graph is not DAG. |
---|
1240 | /// |
---|
1241 | /// \see topologicalSort |
---|
1242 | /// \see dag |
---|
1243 | template <typename Graph, typename NodeMap> |
---|
1244 | bool checkedTopologicalSort(const Graph& graph, NodeMap& order) { |
---|
1245 | using namespace _topology_bits; |
---|
1246 | |
---|
1247 | checkConcept<concept::StaticGraph, Graph>(); |
---|
1248 | checkConcept<concept::ReadWriteMap<typename Graph::Node, int>, NodeMap>(); |
---|
1249 | |
---|
1250 | typedef typename Graph::Node Node; |
---|
1251 | typedef typename Graph::NodeIt NodeIt; |
---|
1252 | typedef typename Graph::Edge Edge; |
---|
1253 | |
---|
1254 | order = constMap<Node, int, -1>(); |
---|
1255 | |
---|
1256 | TopologicalSortVisitor<Graph, NodeMap> |
---|
1257 | visitor(order, countNodes(graph)); |
---|
1258 | |
---|
1259 | DfsVisit<Graph, TopologicalSortVisitor<Graph, NodeMap> > |
---|
1260 | dfs(graph, visitor); |
---|
1261 | |
---|
1262 | dfs.init(); |
---|
1263 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1264 | if (!dfs.reached(it)) { |
---|
1265 | dfs.addSource(it); |
---|
1266 | while (!dfs.emptyQueue()) { |
---|
1267 | Edge edge = dfs.nextEdge(); |
---|
1268 | Node target = graph.target(edge); |
---|
1269 | if (dfs.reached(target) && order[target] == -1) { |
---|
1270 | return false; |
---|
1271 | } |
---|
1272 | dfs.processNextEdge(); |
---|
1273 | } |
---|
1274 | } |
---|
1275 | } |
---|
1276 | return true; |
---|
1277 | } |
---|
1278 | |
---|
1279 | /// \ingroup topology |
---|
1280 | /// |
---|
1281 | /// \brief Check that the given directed graph is a DAG. |
---|
1282 | /// |
---|
1283 | /// Check that the given directed graph is a DAG. The DAG is |
---|
1284 | /// an Directed Acyclic Graph. |
---|
1285 | /// \return %False when the graph is not DAG. |
---|
1286 | /// \see acyclic |
---|
1287 | template <typename Graph> |
---|
1288 | bool dag(const Graph& graph) { |
---|
1289 | |
---|
1290 | checkConcept<concept::StaticGraph, Graph>(); |
---|
1291 | |
---|
1292 | typedef typename Graph::Node Node; |
---|
1293 | typedef typename Graph::NodeIt NodeIt; |
---|
1294 | typedef typename Graph::Edge Edge; |
---|
1295 | |
---|
1296 | typedef typename Graph::template NodeMap<bool> ProcessedMap; |
---|
1297 | |
---|
1298 | typename Dfs<Graph>::template DefProcessedMap<ProcessedMap>:: |
---|
1299 | Create dfs(graph); |
---|
1300 | |
---|
1301 | ProcessedMap processed(graph); |
---|
1302 | dfs.processedMap(processed); |
---|
1303 | |
---|
1304 | dfs.init(); |
---|
1305 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1306 | if (!dfs.reached(it)) { |
---|
1307 | dfs.addSource(it); |
---|
1308 | while (!dfs.emptyQueue()) { |
---|
1309 | Edge edge = dfs.nextEdge(); |
---|
1310 | Node target = graph.target(edge); |
---|
1311 | if (dfs.reached(target) && !processed[target]) { |
---|
1312 | return false; |
---|
1313 | } |
---|
1314 | dfs.processNextEdge(); |
---|
1315 | } |
---|
1316 | } |
---|
1317 | } |
---|
1318 | return true; |
---|
1319 | } |
---|
1320 | |
---|
1321 | /// \ingroup topology |
---|
1322 | /// |
---|
1323 | /// \brief Check that the given undirected graph is acyclic. |
---|
1324 | /// |
---|
1325 | /// Check that the given undirected graph acyclic. |
---|
1326 | /// \param graph The undirected graph. |
---|
1327 | /// \return %True when there is no circle in the graph. |
---|
1328 | /// \see dag |
---|
1329 | template <typename UGraph> |
---|
1330 | bool acyclic(const UGraph& graph) { |
---|
1331 | checkConcept<concept::UGraph, UGraph>(); |
---|
1332 | typedef typename UGraph::Node Node; |
---|
1333 | typedef typename UGraph::NodeIt NodeIt; |
---|
1334 | typedef typename UGraph::Edge Edge; |
---|
1335 | Dfs<UGraph> dfs(graph); |
---|
1336 | dfs.init(); |
---|
1337 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1338 | if (!dfs.reached(it)) { |
---|
1339 | dfs.addSource(it); |
---|
1340 | while (!dfs.emptyQueue()) { |
---|
1341 | Edge edge = dfs.nextEdge(); |
---|
1342 | Node source = graph.source(edge); |
---|
1343 | Node target = graph.target(edge); |
---|
1344 | if (dfs.reached(target) && |
---|
1345 | dfs.predEdge(source) != graph.oppositeEdge(edge)) { |
---|
1346 | return false; |
---|
1347 | } |
---|
1348 | dfs.processNextEdge(); |
---|
1349 | } |
---|
1350 | } |
---|
1351 | } |
---|
1352 | return true; |
---|
1353 | } |
---|
1354 | |
---|
1355 | /// \ingroup topology |
---|
1356 | /// |
---|
1357 | /// \brief Check that the given undirected graph is tree. |
---|
1358 | /// |
---|
1359 | /// Check that the given undirected graph is tree. |
---|
1360 | /// \param graph The undirected graph. |
---|
1361 | /// \return %True when the graph is acyclic and connected. |
---|
1362 | template <typename UGraph> |
---|
1363 | bool tree(const UGraph& graph) { |
---|
1364 | checkConcept<concept::UGraph, UGraph>(); |
---|
1365 | typedef typename UGraph::Node Node; |
---|
1366 | typedef typename UGraph::NodeIt NodeIt; |
---|
1367 | typedef typename UGraph::Edge Edge; |
---|
1368 | Dfs<UGraph> dfs(graph); |
---|
1369 | dfs.init(); |
---|
1370 | dfs.addSource(NodeIt(graph)); |
---|
1371 | while (!dfs.emptyQueue()) { |
---|
1372 | Edge edge = dfs.nextEdge(); |
---|
1373 | Node source = graph.source(edge); |
---|
1374 | Node target = graph.target(edge); |
---|
1375 | if (dfs.reached(target) && |
---|
1376 | dfs.predEdge(source) != graph.oppositeEdge(edge)) { |
---|
1377 | return false; |
---|
1378 | } |
---|
1379 | dfs.processNextEdge(); |
---|
1380 | } |
---|
1381 | for (NodeIt it(graph); it != INVALID; ++it) { |
---|
1382 | if (!dfs.reached(it)) { |
---|
1383 | return false; |
---|
1384 | } |
---|
1385 | } |
---|
1386 | return true; |
---|
1387 | } |
---|
1388 | |
---|
1389 | /// \ingroup topology |
---|
1390 | /// |
---|
1391 | /// \brief Check if the given undirected graph is bipartite or not |
---|
1392 | /// |
---|
1393 | /// The function checks if the given undirected \c graph graph is bipartite |
---|
1394 | /// or not. The \ref Bfs algorithm is used to calculate the result. |
---|
1395 | /// \param graph The undirected graph. |
---|
1396 | /// \return %True if \c graph is bipartite, %false otherwise. |
---|
1397 | /// \sa bipartitePartitions |
---|
1398 | /// |
---|
1399 | /// \author Balazs Attila Mihaly |
---|
1400 | template<typename UGraph> |
---|
1401 | inline bool bipartite(const UGraph &graph){ |
---|
1402 | checkConcept<concept::UGraph, UGraph>(); |
---|
1403 | |
---|
1404 | typedef typename UGraph::NodeIt NodeIt; |
---|
1405 | typedef typename UGraph::EdgeIt EdgeIt; |
---|
1406 | |
---|
1407 | Bfs<UGraph> bfs(graph); |
---|
1408 | bfs.init(); |
---|
1409 | for(NodeIt i(graph);i!=INVALID;++i){ |
---|
1410 | if(!bfs.reached(i)){ |
---|
1411 | bfs.run(i); |
---|
1412 | } |
---|
1413 | } |
---|
1414 | for(EdgeIt i(graph);i!=INVALID;++i){ |
---|
1415 | if(bfs.dist(graph.source(i))==bfs.dist(graph.target(i)))return false; |
---|
1416 | } |
---|
1417 | return true; |
---|
1418 | }; |
---|
1419 | |
---|
1420 | /// \ingroup topology |
---|
1421 | /// |
---|
1422 | /// \brief Check if the given undirected graph is bipartite or not |
---|
1423 | /// |
---|
1424 | /// The function checks if the given undirected graph is bipartite |
---|
1425 | /// or not. The \ref Bfs algorithm is used to calculate the result. |
---|
1426 | /// During the execution, the \c partMap will be set as the two |
---|
1427 | /// partitions of the graph. |
---|
1428 | /// \param graph The undirected graph. |
---|
1429 | /// \retval partMap A writable bool map of nodes. It will be set as the |
---|
1430 | /// two partitions of the graph. |
---|
1431 | /// \return %True if \c graph is bipartite, %false otherwise. |
---|
1432 | /// |
---|
1433 | /// \author Balazs Attila Mihaly |
---|
1434 | /// |
---|
1435 | /// \image html bipartite_partitions.png |
---|
1436 | /// \image latex bipartite_partitions.eps "Bipartite partititions" width=\textwidth |
---|
1437 | template<typename UGraph, typename NodeMap> |
---|
1438 | inline bool bipartitePartitions(const UGraph &graph, NodeMap &partMap){ |
---|
1439 | checkConcept<concept::UGraph, UGraph>(); |
---|
1440 | |
---|
1441 | typedef typename UGraph::Node Node; |
---|
1442 | typedef typename UGraph::NodeIt NodeIt; |
---|
1443 | typedef typename UGraph::EdgeIt EdgeIt; |
---|
1444 | |
---|
1445 | Bfs<UGraph> bfs(graph); |
---|
1446 | bfs.init(); |
---|
1447 | for(NodeIt i(graph);i!=INVALID;++i){ |
---|
1448 | if(!bfs.reached(i)){ |
---|
1449 | bfs.addSource(i); |
---|
1450 | for(Node j=bfs.processNextNode();!bfs.emptyQueue(); |
---|
1451 | j=bfs.processNextNode()){ |
---|
1452 | partMap.set(j,bfs.dist(j)%2==0); |
---|
1453 | } |
---|
1454 | } |
---|
1455 | } |
---|
1456 | for(EdgeIt i(graph);i!=INVALID;++i){ |
---|
1457 | if(bfs.dist(graph.source(i)) == bfs.dist(graph.target(i)))return false; |
---|
1458 | } |
---|
1459 | return true; |
---|
1460 | }; |
---|
1461 | |
---|
1462 | } //namespace lemon |
---|
1463 | |
---|
1464 | #endif //LEMON_TOPOLOGY_H |
---|