1 | /* -*- C++ -*- |
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2 | * src/lemon/graph_utils.h - Part of LEMON, a generic C++ optimization library |
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3 | * |
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4 | * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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5 | * (Egervary Combinatorial Optimization Research Group, 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_GRAPH_UTILS_H |
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18 | #define LEMON_GRAPH_UTILS_H |
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19 | |
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20 | #include <iterator> |
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21 | |
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22 | #include <lemon/invalid.h> |
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23 | #include <lemon/utility.h> |
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24 | |
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25 | ///\ingroup gutils |
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26 | ///\file |
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27 | ///\brief Graph utilities. |
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28 | /// |
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29 | ///\todo Please |
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30 | ///revise the documentation. |
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31 | /// |
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32 | |
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33 | |
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34 | namespace lemon { |
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35 | |
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36 | /// \addtogroup gutils |
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37 | /// @{ |
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38 | |
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39 | /// \brief Function to count the items in the graph. |
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40 | /// |
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41 | /// This function counts the items in the graph. |
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42 | /// The complexity of the function is O(n) because |
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43 | /// it iterates on all of the items. |
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44 | |
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45 | template <typename Graph, typename ItemIt> |
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46 | inline int countItems(const Graph& g) { |
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47 | int num = 0; |
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48 | for (ItemIt it(g); it != INVALID; ++it) { |
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49 | ++num; |
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50 | } |
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51 | return num; |
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52 | } |
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53 | |
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54 | // Node counting: |
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55 | |
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56 | template <typename Graph> |
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57 | inline |
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58 | typename enable_if<typename Graph::NodeNumTag, int>::type |
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59 | _countNodes(const Graph &g) { |
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60 | return g.nodeNum(); |
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61 | } |
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62 | |
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63 | template <typename Graph> |
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64 | inline int _countNodes(Wrap<Graph> w) { |
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65 | return countItems<Graph, typename Graph::NodeIt>(w.value); |
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66 | } |
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67 | |
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68 | /// \brief Function to count the nodes in the graph. |
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69 | /// |
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70 | /// This function counts the nodes in the graph. |
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71 | /// The complexity of the function is O(n) but for some |
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72 | /// graph structure it is specialized to run in O(1). |
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73 | /// |
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74 | /// \todo refer how to specialize it |
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75 | |
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76 | template <typename Graph> |
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77 | inline int countNodes(const Graph& g) { |
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78 | return _countNodes<Graph>(g); |
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79 | } |
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80 | |
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81 | // Edge counting: |
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82 | |
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83 | template <typename Graph> |
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84 | inline |
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85 | typename enable_if<typename Graph::EdgeNumTag, int>::type |
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86 | _countEdges(const Graph &g) { |
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87 | return g.edgeNum(); |
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88 | } |
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89 | |
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90 | template <typename Graph> |
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91 | inline int _countEdges(Wrap<Graph> w) { |
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92 | return countItems<Graph, typename Graph::EdgeIt>(w.value); |
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93 | } |
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94 | |
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95 | /// \brief Function to count the edges in the graph. |
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96 | /// |
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97 | /// This function counts the edges in the graph. |
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98 | /// The complexity of the function is O(e) but for some |
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99 | /// graph structure it is specialized to run in O(1). |
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100 | |
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101 | template <typename Graph> |
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102 | inline int countEdges(const Graph& g) { |
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103 | return _countEdges<Graph>(g); |
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104 | } |
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105 | |
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106 | /// \brief Function to count the symmetric edges in the graph. |
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107 | /// |
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108 | /// This function counts the symmetric edges in the graph. |
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109 | /// The complexity of the function is O(e) but for some |
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110 | /// graph structure it is specialized to run in O(1). |
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111 | template <typename Graph> |
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112 | inline int countSymEdges(const Graph& _g) { |
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113 | return countItems<Graph, typename Graph::SymEdgeIt>(_g); |
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114 | } |
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115 | |
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116 | |
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117 | template <typename Graph, typename DegIt> |
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118 | inline int countNodeDegree(const Graph& _g, const typename Graph::Node& _n) { |
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119 | int num = 0; |
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120 | for (DegIt it(_g, _n); it != INVALID; ++it) { |
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121 | ++num; |
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122 | } |
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123 | return num; |
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124 | } |
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125 | |
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126 | /// Finds an edge between two nodes of a graph. |
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127 | |
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128 | /// Finds an edge from node \c u to node \c v in graph \c g. |
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129 | /// |
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130 | /// If \c prev is \ref INVALID (this is the default value), then |
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131 | /// it finds the first edge from \c u to \c v. Otherwise it looks for |
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132 | /// the next edge from \c u to \c v after \c prev. |
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133 | /// \return The found edge or \ref INVALID if there is no such an edge. |
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134 | /// |
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135 | /// Thus you can iterate through each edge from \c u to \c v as it follows. |
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136 | /// \code |
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137 | /// for(Edge e=findEdge(g,u,v);e!=INVALID;e=findEdge(g,u,v,e)) { |
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138 | /// ... |
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139 | /// } |
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140 | /// \endcode |
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141 | /// \todo We may want to use the \ref concept::GraphBase "GraphBase" |
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142 | /// interface here... |
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143 | /// \bug Untested ... |
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144 | template <typename Graph> |
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145 | typename Graph::Edge findEdge(const Graph &g, |
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146 | typename Graph::Node u, typename Graph::Node v, |
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147 | typename Graph::Edge prev = INVALID) |
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148 | { |
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149 | typename Graph::OutEdgeIt e(g,prev); |
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150 | if(prev==INVALID) g.first(e,u); |
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151 | else ++e; |
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152 | while(e!=INVALID && g.source(e)!=v) ++e; |
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153 | return e; |
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154 | } |
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155 | |
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156 | ///\e |
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157 | |
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158 | ///\todo Please document. |
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159 | /// |
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160 | template <typename Graph> |
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161 | inline int countOutEdges(const Graph& _g, const typename Graph::Node& _n) { |
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162 | return countNodeDegree<Graph, typename Graph::OutEdgeIt>(_g, _n); |
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163 | } |
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164 | |
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165 | ///\e |
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166 | |
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167 | ///\todo Please document. |
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168 | /// |
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169 | template <typename Graph> |
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170 | inline int countInEdges(const Graph& _g, const typename Graph::Node& _n) { |
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171 | return countNodeDegree<Graph, typename Graph::InEdgeIt>(_g, _n); |
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172 | } |
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173 | |
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174 | // graph copy |
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175 | |
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176 | template < |
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177 | typename DestinationGraph, |
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178 | typename SourceGraph, |
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179 | typename NodeBijection> |
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180 | void copyNodes(DestinationGraph& _d, const SourceGraph& _s, |
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181 | NodeBijection& _nb) { |
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182 | for (typename SourceGraph::NodeIt it(_s); it != INVALID; ++it) { |
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183 | _nb[it] = _d.addNode(); |
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184 | } |
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185 | } |
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186 | |
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187 | template < |
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188 | typename DestinationGraph, |
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189 | typename SourceGraph, |
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190 | typename NodeBijection, |
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191 | typename EdgeBijection> |
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192 | void copyEdges(DestinationGraph& _d, const SourceGraph& _s, |
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193 | const NodeBijection& _nb, EdgeBijection& _eb) { |
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194 | for (typename SourceGraph::EdgeIt it(_s); it != INVALID; ++it) { |
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195 | _eb[it] = _d.addEdge(_nb[_s.source(it)], _nb[_s.target(it)]); |
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196 | } |
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197 | } |
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198 | |
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199 | template < |
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200 | typename DestinationGraph, |
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201 | typename SourceGraph, |
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202 | typename NodeBijection, |
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203 | typename EdgeBijection> |
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204 | void copyGraph(DestinationGraph& _d, const SourceGraph& _s, |
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205 | NodeBijection& _nb, EdgeBijection& _eb) { |
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206 | nodeCopy(_d, _s, _nb); |
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207 | edgeCopy(_d, _s, _nb, _eb); |
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208 | } |
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209 | |
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210 | template < |
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211 | typename _DestinationGraph, |
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212 | typename _SourceGraph, |
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213 | typename _NodeBijection |
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214 | =typename _SourceGraph::template NodeMap<typename _DestinationGraph::Node>, |
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215 | typename _EdgeBijection |
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216 | =typename _SourceGraph::template EdgeMap<typename _DestinationGraph::Edge> |
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217 | > |
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218 | class GraphCopy { |
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219 | public: |
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220 | |
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221 | typedef _DestinationGraph DestinationGraph; |
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222 | typedef _SourceGraph SourceGraph; |
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223 | |
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224 | typedef _NodeBijection NodeBijection; |
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225 | typedef _EdgeBijection EdgeBijection; |
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226 | |
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227 | protected: |
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228 | |
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229 | NodeBijection node_bijection; |
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230 | EdgeBijection edge_bijection; |
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231 | |
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232 | public: |
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233 | |
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234 | GraphCopy(DestinationGraph& _d, const SourceGraph& _s) { |
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235 | copyGraph(_d, _s, node_bijection, edge_bijection); |
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236 | } |
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237 | |
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238 | const NodeBijection& getNodeBijection() const { |
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239 | return node_bijection; |
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240 | } |
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241 | |
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242 | const EdgeBijection& getEdgeBijection() const { |
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243 | return edge_bijection; |
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244 | } |
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245 | |
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246 | }; |
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247 | |
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248 | /// @} |
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249 | |
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250 | } //END OF NAMESPACE LEMON |
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251 | |
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252 | #endif |
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