1 | /* -*- C++ -*- |
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2 | * src/lemon/graph_wrapper.h - Part of LEMON, a generic C++ optimization library |
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3 | * |
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4 | * Copyright (C) 2005 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_GRAPH_WRAPPER_H |
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18 | #define LEMON_GRAPH_WRAPPER_H |
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19 | |
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20 | ///\ingroup gwrappers |
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21 | ///\file |
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22 | ///\brief Several graph wrappers. |
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23 | /// |
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24 | ///This file contains several useful graph wrapper functions. |
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25 | /// |
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26 | ///\author Marton Makai |
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27 | |
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28 | #include <lemon/invalid.h> |
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29 | #include <lemon/maps.h> |
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30 | #include <lemon/bits/iterable_graph_extender.h> |
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31 | #include <iostream> |
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32 | |
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33 | namespace lemon { |
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34 | |
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35 | // Graph wrappers |
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36 | |
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37 | /*! |
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38 | \addtogroup gwrappers |
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39 | @{ |
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40 | */ |
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41 | |
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42 | /*! |
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43 | Base type for the Graph Wrappers |
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44 | |
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45 | \warning Graph wrappers are in even more experimental state than the other |
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46 | parts of the lib. Use them at you own risk. |
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47 | |
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48 | This is the base type for most of LEMON graph wrappers. |
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49 | This class implements a trivial graph wrapper i.e. it only wraps the |
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50 | functions and types of the graph. The purpose of this class is to |
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51 | make easier implementing graph wrappers. E.g. if a wrapper is |
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52 | considered which differs from the wrapped graph only in some of its |
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53 | functions or types, then it can be derived from GraphWrapper, and only the |
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54 | differences should be implemented. |
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55 | |
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56 | \author Marton Makai |
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57 | */ |
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58 | template<typename _Graph> |
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59 | class GraphWrapperBase { |
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60 | public: |
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61 | typedef _Graph Graph; |
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62 | /// \todo Is it needed? |
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63 | typedef Graph BaseGraph; |
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64 | typedef Graph ParentGraph; |
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65 | |
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66 | protected: |
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67 | Graph* graph; |
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68 | GraphWrapperBase() : graph(0) { } |
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69 | void setGraph(Graph& _graph) { graph=&_graph; } |
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70 | |
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71 | public: |
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72 | GraphWrapperBase(Graph& _graph) : graph(&_graph) { } |
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73 | |
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74 | typedef typename Graph::Node Node; |
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75 | typedef typename Graph::Edge Edge; |
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76 | |
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77 | void first(Node& i) const { graph->first(i); } |
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78 | void first(Edge& i) const { graph->first(i); } |
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79 | void firstIn(Edge& i, const Node& n) const { graph->firstIn(i, n); } |
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80 | void firstOut(Edge& i, const Node& n ) const { graph->firstOut(i, n); } |
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81 | |
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82 | void next(Node& i) const { graph->next(i); } |
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83 | void next(Edge& i) const { graph->next(i); } |
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84 | void nextIn(Edge& i) const { graph->nextIn(i); } |
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85 | void nextOut(Edge& i) const { graph->nextOut(i); } |
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86 | |
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87 | Node source(const Edge& e) const { return graph->source(e); } |
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88 | Node target(const Edge& e) const { return graph->target(e); } |
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89 | |
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90 | int nodeNum() const { return graph->nodeNum(); } |
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91 | int edgeNum() const { return graph->edgeNum(); } |
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92 | |
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93 | Node addNode() const { return Node(graph->addNode()); } |
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94 | Edge addEdge(const Node& source, const Node& target) const { |
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95 | return Edge(graph->addEdge(source, target)); } |
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96 | |
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97 | void erase(const Node& i) const { graph->erase(i); } |
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98 | void erase(const Edge& i) const { graph->erase(i); } |
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99 | |
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100 | void clear() const { graph->clear(); } |
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101 | |
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102 | bool forward(const Edge& e) const { return graph->forward(e); } |
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103 | bool backward(const Edge& e) const { return graph->backward(e); } |
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104 | |
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105 | int id(const Node& v) const { return graph->id(v); } |
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106 | int id(const Edge& e) const { return graph->id(e); } |
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107 | |
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108 | Edge opposite(const Edge& e) const { return Edge(graph->opposite(e)); } |
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109 | |
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110 | template <typename _Value> |
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111 | class NodeMap : public _Graph::template NodeMap<_Value> { |
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112 | public: |
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113 | typedef typename _Graph::template NodeMap<_Value> Parent; |
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114 | NodeMap(const GraphWrapperBase<_Graph>& gw) : Parent(*gw.graph) { } |
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115 | NodeMap(const GraphWrapperBase<_Graph>& gw, const _Value& value) |
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116 | : Parent(*gw.graph, value) { } |
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117 | }; |
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118 | |
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119 | template <typename _Value> |
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120 | class EdgeMap : public _Graph::template EdgeMap<_Value> { |
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121 | public: |
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122 | typedef typename _Graph::template EdgeMap<_Value> Parent; |
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123 | EdgeMap(const GraphWrapperBase<_Graph>& gw) : Parent(*gw.graph) { } |
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124 | EdgeMap(const GraphWrapperBase<_Graph>& gw, const _Value& value) |
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125 | : Parent(*gw.graph, value) { } |
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126 | }; |
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127 | |
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128 | }; |
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129 | |
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130 | template <typename _Graph> |
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131 | class GraphWrapper : |
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132 | public IterableGraphExtender<GraphWrapperBase<_Graph> > { |
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133 | public: |
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134 | typedef _Graph Graph; |
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135 | typedef IterableGraphExtender<GraphWrapperBase<_Graph> > Parent; |
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136 | protected: |
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137 | GraphWrapper() : Parent() { } |
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138 | |
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139 | public: |
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140 | GraphWrapper(Graph& _graph) { setGraph(_graph); } |
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141 | }; |
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142 | |
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143 | template <typename _Graph> |
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144 | class RevGraphWrapperBase : public GraphWrapperBase<_Graph> { |
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145 | public: |
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146 | typedef _Graph Graph; |
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147 | typedef GraphWrapperBase<_Graph> Parent; |
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148 | protected: |
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149 | RevGraphWrapperBase() : Parent() { } |
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150 | public: |
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151 | typedef typename Parent::Node Node; |
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152 | typedef typename Parent::Edge Edge; |
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153 | |
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154 | using Parent::first; |
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155 | void firstIn(Edge& i, const Node& n) const { Parent::firstOut(i, n); } |
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156 | void firstOut(Edge& i, const Node& n ) const { Parent::firstIn(i, n); } |
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157 | |
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158 | using Parent::next; |
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159 | void nextIn(Edge& i) const { Parent::nextOut(i); } |
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160 | void nextOut(Edge& i) const { Parent::nextIn(i); } |
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161 | |
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162 | Node source(const Edge& e) const { return Parent::target(e); } |
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163 | Node target(const Edge& e) const { return Parent::source(e); } |
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164 | }; |
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165 | |
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166 | |
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167 | /// A graph wrapper which reverses the orientation of the edges. |
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168 | |
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169 | ///\warning Graph wrappers are in even more experimental state than the other |
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170 | ///parts of the lib. Use them at you own risk. |
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171 | /// |
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172 | /// Let \f$G=(V, A)\f$ be a directed graph and |
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173 | /// suppose that a graph instange \c g of type |
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174 | /// \c ListGraph implements \f$G\f$. |
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175 | /// \code |
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176 | /// ListGraph g; |
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177 | /// \endcode |
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178 | /// For each directed edge |
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179 | /// \f$e\in A\f$, let \f$\bar e\f$ denote the edge obtained by |
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180 | /// reversing its orientation. |
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181 | /// Then RevGraphWrapper implements the graph structure with node-set |
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182 | /// \f$V\f$ and edge-set |
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183 | /// \f$\{\bar e : e\in A \}\f$, i.e. the graph obtained from \f$G\f$ be |
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184 | /// reversing the orientation of its edges. The following code shows how |
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185 | /// such an instance can be constructed. |
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186 | /// \code |
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187 | /// RevGraphWrapper<ListGraph> gw(g); |
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188 | /// \endcode |
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189 | ///\author Marton Makai |
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190 | template<typename _Graph> |
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191 | class RevGraphWrapper : |
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192 | public IterableGraphExtender<RevGraphWrapperBase<_Graph> > { |
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193 | public: |
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194 | typedef _Graph Graph; |
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195 | typedef IterableGraphExtender< |
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196 | RevGraphWrapperBase<_Graph> > Parent; |
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197 | protected: |
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198 | RevGraphWrapper() { } |
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199 | public: |
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200 | RevGraphWrapper(_Graph& _graph) { setGraph(_graph); } |
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201 | }; |
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202 | |
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203 | |
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204 | template <typename _Graph, typename NodeFilterMap, typename EdgeFilterMap> |
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205 | class SubGraphWrapperBase : public GraphWrapperBase<_Graph> { |
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206 | public: |
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207 | typedef _Graph Graph; |
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208 | typedef GraphWrapperBase<_Graph> Parent; |
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209 | protected: |
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210 | NodeFilterMap* node_filter_map; |
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211 | EdgeFilterMap* edge_filter_map; |
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212 | SubGraphWrapperBase() : Parent(), |
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213 | node_filter_map(0), edge_filter_map(0) { } |
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214 | |
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215 | void setNodeFilterMap(NodeFilterMap& _node_filter_map) { |
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216 | node_filter_map=&_node_filter_map; |
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217 | } |
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218 | void setEdgeFilterMap(EdgeFilterMap& _edge_filter_map) { |
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219 | edge_filter_map=&_edge_filter_map; |
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220 | } |
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221 | |
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222 | public: |
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223 | // SubGraphWrapperBase(Graph& _graph, |
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224 | // NodeFilterMap& _node_filter_map, |
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225 | // EdgeFilterMap& _edge_filter_map) : |
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226 | // Parent(&_graph), |
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227 | // node_filter_map(&node_filter_map), |
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228 | // edge_filter_map(&edge_filter_map) { } |
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229 | |
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230 | typedef typename Parent::Node Node; |
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231 | typedef typename Parent::Edge Edge; |
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232 | |
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233 | void first(Node& i) const { |
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234 | Parent::first(i); |
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235 | while (i!=INVALID && !(*node_filter_map)[i]) Parent::next(i); |
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236 | } |
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237 | void first(Edge& i) const { |
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238 | Parent::first(i); |
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239 | while (i!=INVALID && !(*edge_filter_map)[i]) Parent::next(i); |
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240 | } |
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241 | void firstIn(Edge& i, const Node& n) const { |
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242 | Parent::firstIn(i, n); |
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243 | while (i!=INVALID && !(*edge_filter_map)[i]) Parent::nextIn(i); |
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244 | } |
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245 | void firstOut(Edge& i, const Node& n) const { |
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246 | Parent::firstOut(i, n); |
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247 | while (i!=INVALID && !(*edge_filter_map)[i]) Parent::nextOut(i); |
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248 | } |
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249 | |
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250 | void next(Node& i) const { |
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251 | Parent::next(i); |
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252 | while (i!=INVALID && !(*node_filter_map)[i]) Parent::next(i); |
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253 | } |
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254 | void next(Edge& i) const { |
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255 | Parent::next(i); |
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256 | while (i!=INVALID && !(*edge_filter_map)[i]) Parent::next(i); |
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257 | } |
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258 | void nextIn(Edge& i) const { |
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259 | Parent::nextIn(i); |
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260 | while (i!=INVALID && !(*edge_filter_map)[i]) Parent::nextIn(i); |
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261 | } |
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262 | void nextOut(Edge& i) const { |
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263 | Parent::nextOut(i); |
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264 | while (i!=INVALID && !(*edge_filter_map)[i]) Parent::nextOut(i); |
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265 | } |
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266 | |
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267 | /// This function hides \c n in the graph, i.e. the iteration |
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268 | /// jumps over it. This is done by simply setting the value of \c n |
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269 | /// to be false in the corresponding node-map. |
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270 | void hide(const Node& n) const { node_filter_map->set(n, false); } |
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271 | |
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272 | /// This function hides \c e in the graph, i.e. the iteration |
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273 | /// jumps over it. This is done by simply setting the value of \c e |
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274 | /// to be false in the corresponding edge-map. |
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275 | void hide(const Edge& e) const { edge_filter_map->set(e, false); } |
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276 | |
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277 | /// The value of \c n is set to be true in the node-map which stores |
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278 | /// hide information. If \c n was hidden previuosly, then it is shown |
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279 | /// again |
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280 | void unHide(const Node& n) const { node_filter_map->set(n, true); } |
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281 | |
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282 | /// The value of \c e is set to be true in the edge-map which stores |
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283 | /// hide information. If \c e was hidden previuosly, then it is shown |
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284 | /// again |
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285 | void unHide(const Edge& e) const { edge_filter_map->set(e, true); } |
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286 | |
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287 | /// Returns true if \c n is hidden. |
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288 | bool hidden(const Node& n) const { return !(*node_filter_map)[n]; } |
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289 | |
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290 | /// Returns true if \c n is hidden. |
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291 | bool hidden(const Edge& e) const { return !(*edge_filter_map)[e]; } |
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292 | |
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293 | /// \warning This is a linear time operation and works only if s |
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294 | /// \c Graph::NodeIt is defined. |
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295 | /// \todo assign tags. |
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296 | int nodeNum() const { |
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297 | int i=0; |
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298 | Node n; |
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299 | for (first(n); n!=INVALID; next(n)) ++i; |
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300 | return i; |
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301 | } |
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302 | |
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303 | /// \warning This is a linear time operation and works only if |
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304 | /// \c Graph::EdgeIt is defined. |
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305 | /// \todo assign tags. |
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306 | int edgeNum() const { |
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307 | int i=0; |
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308 | Edge e; |
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309 | for (first(e); e!=INVALID; next(e)) ++i; |
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310 | return i; |
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311 | } |
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312 | |
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313 | |
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314 | }; |
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315 | |
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316 | /*! \brief A graph wrapper for hiding nodes and edges from a graph. |
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317 | |
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318 | \warning Graph wrappers are in even more experimental state than the other |
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319 | parts of the lib. Use them at you own risk. |
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320 | |
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321 | SubGraphWrapper shows the graph with filtered node-set and |
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322 | edge-set. |
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323 | Let \f$G=(V, A)\f$ be a directed graph |
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324 | and suppose that the graph instance \c g of type ListGraph implements |
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325 | \f$G\f$. |
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326 | Let moreover \f$b_V\f$ and |
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327 | \f$b_A\f$ be bool-valued functions resp. on the node-set and edge-set. |
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328 | SubGraphWrapper<...>::NodeIt iterates |
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329 | on the node-set \f$\{v\in V : b_V(v)=true\}\f$ and |
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330 | SubGraphWrapper<...>::EdgeIt iterates |
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331 | on the edge-set \f$\{e\in A : b_A(e)=true\}\f$. Similarly, |
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332 | SubGraphWrapper<...>::OutEdgeIt and SubGraphWrapper<...>::InEdgeIt iterates |
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333 | only on edges leaving and entering a specific node which have true value. |
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334 | |
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335 | We have to note that this does not mean that an |
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336 | induced subgraph is obtained, the node-iterator cares only the filter |
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337 | on the node-set, and the edge-iterators care only the filter on the |
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338 | edge-set. |
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339 | \code |
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340 | typedef ListGraph Graph; |
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341 | Graph g; |
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342 | typedef Graph::Node Node; |
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343 | typedef Graph::Edge Edge; |
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344 | Node u=g.addNode(); //node of id 0 |
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345 | Node v=g.addNode(); //node of id 1 |
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346 | Node e=g.addEdge(u, v); //edge of id 0 |
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347 | Node f=g.addEdge(v, u); //edge of id 1 |
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348 | Graph::NodeMap<bool> nm(g, true); |
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349 | nm.set(u, false); |
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350 | Graph::EdgeMap<bool> em(g, true); |
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351 | em.set(e, false); |
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352 | typedef SubGraphWrapper<Graph, Graph::NodeMap<bool>, Graph::EdgeMap<bool> > SubGW; |
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353 | SubGW gw(g, nm, em); |
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354 | for (SubGW::NodeIt n(gw); n!=INVALID; ++n) std::cout << g.id(n) << std::endl; |
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355 | std::cout << ":-)" << std::endl; |
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356 | for (SubGW::EdgeIt e(gw); e!=INVALID; ++e) std::cout << g.id(e) << std::endl; |
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357 | \endcode |
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358 | The output of the above code is the following. |
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359 | \code |
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360 | 1 |
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361 | :-) |
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362 | 1 |
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363 | \endcode |
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364 | Note that \c n is of type \c SubGW::NodeIt, but it can be converted to |
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365 | \c Graph::Node that is why \c g.id(n) can be applied. |
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366 | |
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367 | For other examples see also the documentation of NodeSubGraphWrapper and |
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368 | EdgeSubGraphWrapper. |
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369 | |
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370 | \author Marton Makai |
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371 | */ |
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372 | template<typename _Graph, typename NodeFilterMap, |
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373 | typename EdgeFilterMap> |
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374 | class SubGraphWrapper : |
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375 | public IterableGraphExtender< |
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376 | SubGraphWrapperBase<_Graph, NodeFilterMap, EdgeFilterMap> > { |
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377 | public: |
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378 | typedef _Graph Graph; |
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379 | typedef IterableGraphExtender< |
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380 | SubGraphWrapperBase<_Graph, NodeFilterMap, EdgeFilterMap> > Parent; |
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381 | protected: |
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382 | SubGraphWrapper() { } |
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383 | public: |
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384 | SubGraphWrapper(_Graph& _graph, NodeFilterMap& _node_filter_map, |
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385 | EdgeFilterMap& _edge_filter_map) { |
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386 | setGraph(_graph); |
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387 | setNodeFilterMap(_node_filter_map); |
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388 | setEdgeFilterMap(_edge_filter_map); |
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389 | } |
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390 | }; |
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391 | |
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392 | |
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393 | |
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394 | /*! \brief A wrapper for hiding nodes from a graph. |
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395 | |
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396 | \warning Graph wrappers are in even more experimental state than the other |
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397 | parts of the lib. Use them at you own risk. |
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398 | |
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399 | A wrapper for hiding nodes from a graph. |
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400 | This wrapper specializes SubGraphWrapper in the way that only the node-set |
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401 | can be filtered. Note that this does not mean of considering induced |
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402 | subgraph, the edge-iterators consider the original edge-set. |
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403 | \author Marton Makai |
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404 | */ |
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405 | template<typename Graph, typename NodeFilterMap> |
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406 | class NodeSubGraphWrapper : |
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407 | public SubGraphWrapper<Graph, NodeFilterMap, |
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408 | ConstMap<typename Graph::Edge,bool> > { |
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409 | public: |
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410 | typedef SubGraphWrapper<Graph, NodeFilterMap, |
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411 | ConstMap<typename Graph::Edge,bool> > Parent; |
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412 | protected: |
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413 | ConstMap<typename Graph::Edge, bool> const_true_map; |
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414 | public: |
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415 | NodeSubGraphWrapper(Graph& _graph, NodeFilterMap& _node_filter_map) : |
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416 | Parent(), const_true_map(true) { |
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417 | Parent::setGraph(_graph); |
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418 | Parent::setNodeFilterMap(_node_filter_map); |
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419 | Parent::setEdgeFilterMap(const_true_map); |
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420 | } |
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421 | }; |
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422 | |
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423 | |
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424 | /*! \brief A wrapper for hiding edges from a graph. |
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425 | |
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426 | \warning Graph wrappers are in even more experimental state than the other |
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427 | parts of the lib. Use them at you own risk. |
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428 | |
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429 | A wrapper for hiding edges from a graph. |
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430 | This wrapper specializes SubGraphWrapper in the way that only the edge-set |
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431 | can be filtered. The usefulness of this wrapper is demonstrated in the |
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432 | problem of searching a maximum number of edge-disjoint shortest paths |
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433 | between |
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434 | two nodes \c s and \c t. Shortest here means being shortest w.r.t. |
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435 | non-negative edge-lengths. Note that |
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436 | the comprehension of the presented solution |
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437 | need's some elementary knowledge from combinatorial optimization. |
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438 | |
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439 | If a single shortest path is to be |
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440 | searched between \c s and \c t, then this can be done easily by |
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441 | applying the Dijkstra algorithm. What happens, if a maximum number of |
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442 | edge-disjoint shortest paths is to be computed. It can be proved that an |
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443 | edge can be in a shortest path if and only if it is tight with respect to |
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444 | the potential function computed by Dijkstra. Moreover, any path containing |
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445 | only such edges is a shortest one. Thus we have to compute a maximum number |
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446 | of edge-disjoint paths between \c s and \c t in the graph which has edge-set |
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447 | all the tight edges. The computation will be demonstrated on the following |
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448 | graph, which is read from a dimacs file. |
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449 | |
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450 | \dot |
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451 | digraph lemon_dot_example { |
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452 | node [ shape=ellipse, fontname=Helvetica, fontsize=10 ]; |
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453 | n0 [ label="0 (s)" ]; |
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454 | n1 [ label="1" ]; |
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455 | n2 [ label="2" ]; |
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456 | n3 [ label="3" ]; |
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457 | n4 [ label="4" ]; |
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458 | n5 [ label="5" ]; |
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459 | n6 [ label="6 (t)" ]; |
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460 | edge [ shape=ellipse, fontname=Helvetica, fontsize=10 ]; |
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461 | n5 -> n6 [ label="9, length:4" ]; |
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462 | n4 -> n6 [ label="8, length:2" ]; |
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463 | n3 -> n5 [ label="7, length:1" ]; |
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464 | n2 -> n5 [ label="6, length:3" ]; |
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465 | n2 -> n6 [ label="5, length:5" ]; |
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466 | n2 -> n4 [ label="4, length:2" ]; |
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467 | n1 -> n4 [ label="3, length:3" ]; |
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468 | n0 -> n3 [ label="2, length:1" ]; |
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469 | n0 -> n2 [ label="1, length:2" ]; |
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470 | n0 -> n1 [ label="0, length:3" ]; |
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471 | } |
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472 | \enddot |
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473 | |
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474 | \code |
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475 | Graph g; |
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476 | Node s, t; |
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477 | LengthMap length(g); |
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478 | |
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479 | readDimacs(std::cin, g, length, s, t); |
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480 | |
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481 | cout << "edges with lengths (of form id, source--length->target): " << endl; |
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482 | for(EdgeIt e(g); e!=INVALID; ++e) |
---|
483 | cout << g.id(e) << ", " << g.id(g.source(e)) << "--" |
---|
484 | << length[e] << "->" << g.id(g.target(e)) << endl; |
---|
485 | |
---|
486 | cout << "s: " << g.id(s) << " t: " << g.id(t) << endl; |
---|
487 | \endcode |
---|
488 | Next, the potential function is computed with Dijkstra. |
---|
489 | \code |
---|
490 | typedef Dijkstra<Graph, LengthMap> Dijkstra; |
---|
491 | Dijkstra dijkstra(g, length); |
---|
492 | dijkstra.run(s); |
---|
493 | \endcode |
---|
494 | Next, we consrtruct a map which filters the edge-set to the tight edges. |
---|
495 | \code |
---|
496 | typedef TightEdgeFilterMap<Graph, const Dijkstra::DistMap, LengthMap> |
---|
497 | TightEdgeFilter; |
---|
498 | TightEdgeFilter tight_edge_filter(g, dijkstra.distMap(), length); |
---|
499 | |
---|
500 | typedef EdgeSubGraphWrapper<Graph, TightEdgeFilter> SubGW; |
---|
501 | SubGW gw(g, tight_edge_filter); |
---|
502 | \endcode |
---|
503 | Then, the maximum nimber of edge-disjoint \c s-\c t paths are computed |
---|
504 | with a max flow algorithm Preflow. |
---|
505 | \code |
---|
506 | ConstMap<Edge, int> const_1_map(1); |
---|
507 | Graph::EdgeMap<int> flow(g, 0); |
---|
508 | |
---|
509 | Preflow<SubGW, int, ConstMap<Edge, int>, Graph::EdgeMap<int> > |
---|
510 | preflow(gw, s, t, const_1_map, flow); |
---|
511 | preflow.run(); |
---|
512 | \endcode |
---|
513 | Last, the output is: |
---|
514 | \code |
---|
515 | cout << "maximum number of edge-disjoint shortest path: " |
---|
516 | << preflow.flowValue() << endl; |
---|
517 | cout << "edges of the maximum number of edge-disjoint shortest s-t paths: " |
---|
518 | << endl; |
---|
519 | for(EdgeIt e(g); e!=INVALID; ++e) |
---|
520 | if (flow[e]) |
---|
521 | cout << " " << g.id(g.source(e)) << "--" |
---|
522 | << length[e] << "->" << g.id(g.target(e)) << endl; |
---|
523 | \endcode |
---|
524 | The program has the following (expected :-)) output: |
---|
525 | \code |
---|
526 | edges with lengths (of form id, source--length->target): |
---|
527 | 9, 5--4->6 |
---|
528 | 8, 4--2->6 |
---|
529 | 7, 3--1->5 |
---|
530 | 6, 2--3->5 |
---|
531 | 5, 2--5->6 |
---|
532 | 4, 2--2->4 |
---|
533 | 3, 1--3->4 |
---|
534 | 2, 0--1->3 |
---|
535 | 1, 0--2->2 |
---|
536 | 0, 0--3->1 |
---|
537 | s: 0 t: 6 |
---|
538 | maximum number of edge-disjoint shortest path: 2 |
---|
539 | edges of the maximum number of edge-disjoint shortest s-t paths: |
---|
540 | 9, 5--4->6 |
---|
541 | 8, 4--2->6 |
---|
542 | 7, 3--1->5 |
---|
543 | 4, 2--2->4 |
---|
544 | 2, 0--1->3 |
---|
545 | 1, 0--2->2 |
---|
546 | \endcode |
---|
547 | |
---|
548 | \author Marton Makai |
---|
549 | */ |
---|
550 | template<typename Graph, typename EdgeFilterMap> |
---|
551 | class EdgeSubGraphWrapper : |
---|
552 | public SubGraphWrapper<Graph, ConstMap<typename Graph::Node,bool>, |
---|
553 | EdgeFilterMap> { |
---|
554 | public: |
---|
555 | typedef SubGraphWrapper<Graph, ConstMap<typename Graph::Node,bool>, |
---|
556 | EdgeFilterMap> Parent; |
---|
557 | protected: |
---|
558 | ConstMap<typename Graph::Node, bool> const_true_map; |
---|
559 | public: |
---|
560 | EdgeSubGraphWrapper(Graph& _graph, EdgeFilterMap& _edge_filter_map) : |
---|
561 | Parent(), const_true_map(true) { |
---|
562 | Parent::setGraph(_graph); |
---|
563 | Parent::setNodeFilterMap(const_true_map); |
---|
564 | Parent::setEdgeFilterMap(_edge_filter_map); |
---|
565 | } |
---|
566 | }; |
---|
567 | |
---|
568 | |
---|
569 | template<typename Graph> |
---|
570 | class UndirGraphWrapper : public GraphWrapper<Graph> { |
---|
571 | public: |
---|
572 | typedef GraphWrapper<Graph> Parent; |
---|
573 | protected: |
---|
574 | UndirGraphWrapper() : GraphWrapper<Graph>() { } |
---|
575 | |
---|
576 | public: |
---|
577 | typedef typename GraphWrapper<Graph>::Node Node; |
---|
578 | typedef typename GraphWrapper<Graph>::NodeIt NodeIt; |
---|
579 | typedef typename GraphWrapper<Graph>::Edge Edge; |
---|
580 | typedef typename GraphWrapper<Graph>::EdgeIt EdgeIt; |
---|
581 | |
---|
582 | UndirGraphWrapper(Graph& _graph) : GraphWrapper<Graph>(_graph) { } |
---|
583 | |
---|
584 | class OutEdgeIt { |
---|
585 | friend class UndirGraphWrapper<Graph>; |
---|
586 | bool out_or_in; //true iff out |
---|
587 | typename Graph::OutEdgeIt out; |
---|
588 | typename Graph::InEdgeIt in; |
---|
589 | public: |
---|
590 | OutEdgeIt() { } |
---|
591 | OutEdgeIt(const Invalid& i) : Edge(i) { } |
---|
592 | OutEdgeIt(const UndirGraphWrapper<Graph>& _G, const Node& _n) { |
---|
593 | out_or_in=true; _G.graph->first(out, _n); |
---|
594 | if (!(_G.graph->valid(out))) { out_or_in=false; _G.graph->first(in, _n); } |
---|
595 | } |
---|
596 | operator Edge() const { |
---|
597 | if (out_or_in) return Edge(out); else return Edge(in); |
---|
598 | } |
---|
599 | }; |
---|
600 | |
---|
601 | typedef OutEdgeIt InEdgeIt; |
---|
602 | |
---|
603 | using GraphWrapper<Graph>::first; |
---|
604 | OutEdgeIt& first(OutEdgeIt& i, const Node& p) const { |
---|
605 | i=OutEdgeIt(*this, p); return i; |
---|
606 | } |
---|
607 | |
---|
608 | using GraphWrapper<Graph>::next; |
---|
609 | |
---|
610 | OutEdgeIt& next(OutEdgeIt& e) const { |
---|
611 | if (e.out_or_in) { |
---|
612 | typename Graph::Node n=this->graph->source(e.out); |
---|
613 | this->graph->next(e.out); |
---|
614 | if (!this->graph->valid(e.out)) { |
---|
615 | e.out_or_in=false; this->graph->first(e.in, n); } |
---|
616 | } else { |
---|
617 | this->graph->next(e.in); |
---|
618 | } |
---|
619 | return e; |
---|
620 | } |
---|
621 | |
---|
622 | Node aNode(const OutEdgeIt& e) const { |
---|
623 | if (e.out_or_in) return this->graph->source(e); else |
---|
624 | return this->graph->target(e); } |
---|
625 | Node bNode(const OutEdgeIt& e) const { |
---|
626 | if (e.out_or_in) return this->graph->target(e); else |
---|
627 | return this->graph->source(e); } |
---|
628 | |
---|
629 | // KEEP_MAPS(Parent, UndirGraphWrapper); |
---|
630 | |
---|
631 | }; |
---|
632 | |
---|
633 | // /// \brief An undirected graph template. |
---|
634 | // /// |
---|
635 | // ///\warning Graph wrappers are in even more experimental state than the other |
---|
636 | // ///parts of the lib. Use them at your own risk. |
---|
637 | // /// |
---|
638 | // /// An undirected graph template. |
---|
639 | // /// This class works as an undirected graph and a directed graph of |
---|
640 | // /// class \c Graph is used for the physical storage. |
---|
641 | // /// \ingroup graphs |
---|
642 | template<typename Graph> |
---|
643 | class UndirGraph : public UndirGraphWrapper<Graph> { |
---|
644 | typedef UndirGraphWrapper<Graph> Parent; |
---|
645 | protected: |
---|
646 | Graph gr; |
---|
647 | public: |
---|
648 | UndirGraph() : UndirGraphWrapper<Graph>() { |
---|
649 | Parent::setGraph(gr); |
---|
650 | } |
---|
651 | |
---|
652 | // KEEP_MAPS(Parent, UndirGraph); |
---|
653 | }; |
---|
654 | |
---|
655 | |
---|
656 | template <typename _Graph, |
---|
657 | typename ForwardFilterMap, typename BackwardFilterMap> |
---|
658 | class SubBidirGraphWrapperBase : public GraphWrapperBase<_Graph> { |
---|
659 | public: |
---|
660 | typedef _Graph Graph; |
---|
661 | typedef GraphWrapperBase<_Graph> Parent; |
---|
662 | protected: |
---|
663 | ForwardFilterMap* forward_filter; |
---|
664 | BackwardFilterMap* backward_filter; |
---|
665 | SubBidirGraphWrapperBase() : Parent(), |
---|
666 | forward_filter(0), backward_filter(0) { } |
---|
667 | |
---|
668 | void setForwardFilterMap(ForwardFilterMap& _forward_filter) { |
---|
669 | forward_filter=&_forward_filter; |
---|
670 | } |
---|
671 | void setBackwardFilterMap(BackwardFilterMap& _backward_filter) { |
---|
672 | backward_filter=&_backward_filter; |
---|
673 | } |
---|
674 | |
---|
675 | public: |
---|
676 | // SubGraphWrapperBase(Graph& _graph, |
---|
677 | // NodeFilterMap& _node_filter_map, |
---|
678 | // EdgeFilterMap& _edge_filter_map) : |
---|
679 | // Parent(&_graph), |
---|
680 | // node_filter_map(&node_filter_map), |
---|
681 | // edge_filter_map(&edge_filter_map) { } |
---|
682 | |
---|
683 | typedef typename Parent::Node Node; |
---|
684 | typedef typename _Graph::Edge GraphEdge; |
---|
685 | template <typename T> class EdgeMap; |
---|
686 | /// SubBidirGraphWrapperBase<..., ..., ...>::Edge is inherited from |
---|
687 | /// _Graph::Edge. It contains an extra bool flag which is true |
---|
688 | /// if and only if the |
---|
689 | /// edge is the backward version of the original edge. |
---|
690 | class Edge : public _Graph::Edge { |
---|
691 | friend class SubBidirGraphWrapperBase< |
---|
692 | Graph, ForwardFilterMap, BackwardFilterMap>; |
---|
693 | template<typename T> friend class EdgeMap; |
---|
694 | protected: |
---|
695 | bool backward; //true, iff backward |
---|
696 | public: |
---|
697 | Edge() { } |
---|
698 | /// \todo =false is needed, or causes problems? |
---|
699 | /// If \c _backward is false, then we get an edge corresponding to the |
---|
700 | /// original one, otherwise its oppositely directed pair is obtained. |
---|
701 | Edge(const typename _Graph::Edge& e, bool _backward/*=false*/) : |
---|
702 | _Graph::Edge(e), backward(_backward) { } |
---|
703 | Edge(Invalid i) : _Graph::Edge(i), backward(true) { } |
---|
704 | bool operator==(const Edge& v) const { |
---|
705 | return (this->backward==v.backward && |
---|
706 | static_cast<typename _Graph::Edge>(*this)== |
---|
707 | static_cast<typename _Graph::Edge>(v)); |
---|
708 | } |
---|
709 | bool operator!=(const Edge& v) const { |
---|
710 | return (this->backward!=v.backward || |
---|
711 | static_cast<typename _Graph::Edge>(*this)!= |
---|
712 | static_cast<typename _Graph::Edge>(v)); |
---|
713 | } |
---|
714 | }; |
---|
715 | |
---|
716 | void first(Node& i) const { |
---|
717 | Parent::first(i); |
---|
718 | } |
---|
719 | |
---|
720 | void first(Edge& i) const { |
---|
721 | Parent::first(i); |
---|
722 | i.backward=false; |
---|
723 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
724 | !(*forward_filter)[i]) Parent::next(i); |
---|
725 | if (*static_cast<GraphEdge*>(&i)==INVALID) { |
---|
726 | Parent::first(i); |
---|
727 | i.backward=true; |
---|
728 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
729 | !(*backward_filter)[i]) Parent::next(i); |
---|
730 | } |
---|
731 | } |
---|
732 | |
---|
733 | void firstIn(Edge& i, const Node& n) const { |
---|
734 | Parent::firstIn(i, n); |
---|
735 | i.backward=false; |
---|
736 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
737 | !(*forward_filter)[i]) Parent::nextIn(i); |
---|
738 | if (*static_cast<GraphEdge*>(&i)==INVALID) { |
---|
739 | Parent::firstOut(i, n); |
---|
740 | i.backward=true; |
---|
741 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
742 | !(*backward_filter)[i]) Parent::nextOut(i); |
---|
743 | } |
---|
744 | } |
---|
745 | |
---|
746 | void firstOut(Edge& i, const Node& n) const { |
---|
747 | Parent::firstOut(i, n); |
---|
748 | i.backward=false; |
---|
749 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
750 | !(*forward_filter)[i]) Parent::nextOut(i); |
---|
751 | if (*static_cast<GraphEdge*>(&i)==INVALID) { |
---|
752 | Parent::firstIn(i, n); |
---|
753 | i.backward=true; |
---|
754 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
755 | !(*backward_filter)[i]) Parent::nextIn(i); |
---|
756 | } |
---|
757 | } |
---|
758 | |
---|
759 | void next(Node& i) const { |
---|
760 | Parent::next(i); |
---|
761 | } |
---|
762 | |
---|
763 | void next(Edge& i) const { |
---|
764 | if (!(i.backward)) { |
---|
765 | Parent::next(i); |
---|
766 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
767 | !(*forward_filter)[i]) Parent::next(i); |
---|
768 | if (*static_cast<GraphEdge*>(&i)==INVALID) { |
---|
769 | Parent::first(i); |
---|
770 | i.backward=true; |
---|
771 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
772 | !(*backward_filter)[i]) Parent::next(i); |
---|
773 | } |
---|
774 | } else { |
---|
775 | Parent::next(i); |
---|
776 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
777 | !(*backward_filter)[i]) Parent::next(i); |
---|
778 | } |
---|
779 | } |
---|
780 | |
---|
781 | void nextIn(Edge& i) const { |
---|
782 | if (!(i.backward)) { |
---|
783 | Node n=Parent::target(i); |
---|
784 | Parent::nextIn(i); |
---|
785 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
786 | !(*forward_filter)[i]) Parent::nextIn(i); |
---|
787 | if (*static_cast<GraphEdge*>(&i)==INVALID) { |
---|
788 | Parent::firstOut(i, n); |
---|
789 | i.backward=true; |
---|
790 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
791 | !(*backward_filter)[i]) Parent::nextOut(i); |
---|
792 | } |
---|
793 | } else { |
---|
794 | Parent::nextOut(i); |
---|
795 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
796 | !(*backward_filter)[i]) Parent::nextOut(i); |
---|
797 | } |
---|
798 | } |
---|
799 | |
---|
800 | void nextOut(Edge& i) const { |
---|
801 | if (!(i.backward)) { |
---|
802 | Node n=Parent::source(i); |
---|
803 | Parent::nextOut(i); |
---|
804 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
805 | !(*forward_filter)[i]) Parent::nextOut(i); |
---|
806 | if (*static_cast<GraphEdge*>(&i)==INVALID) { |
---|
807 | Parent::firstIn(i, n); |
---|
808 | i.backward=true; |
---|
809 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
810 | !(*backward_filter)[i]) Parent::nextIn(i); |
---|
811 | } |
---|
812 | } else { |
---|
813 | Parent::nextIn(i); |
---|
814 | while (*static_cast<GraphEdge*>(&i)!=INVALID && |
---|
815 | !(*backward_filter)[i]) Parent::nextIn(i); |
---|
816 | } |
---|
817 | } |
---|
818 | |
---|
819 | Node source(Edge e) const { |
---|
820 | return ((!e.backward) ? this->graph->source(e) : this->graph->target(e)); } |
---|
821 | Node target(Edge e) const { |
---|
822 | return ((!e.backward) ? this->graph->target(e) : this->graph->source(e)); } |
---|
823 | |
---|
824 | /// Gives back the opposite edge. |
---|
825 | Edge opposite(const Edge& e) const { |
---|
826 | Edge f=e; |
---|
827 | f.backward=!f.backward; |
---|
828 | return f; |
---|
829 | } |
---|
830 | |
---|
831 | /// \warning This is a linear time operation and works only if |
---|
832 | /// \c Graph::EdgeIt is defined. |
---|
833 | /// \todo hmm |
---|
834 | int edgeNum() const { |
---|
835 | int i=0; |
---|
836 | Edge e; |
---|
837 | for (first(e); e!=INVALID; next(e)) ++i; |
---|
838 | return i; |
---|
839 | } |
---|
840 | |
---|
841 | bool forward(const Edge& e) const { return !e.backward; } |
---|
842 | bool backward(const Edge& e) const { return e.backward; } |
---|
843 | |
---|
844 | template <typename T> |
---|
845 | /// \c SubBidirGraphWrapperBase<..., ..., ...>::EdgeMap contains two |
---|
846 | /// _Graph::EdgeMap one for the forward edges and |
---|
847 | /// one for the backward edges. |
---|
848 | class EdgeMap { |
---|
849 | template <typename TT> friend class EdgeMap; |
---|
850 | typename _Graph::template EdgeMap<T> forward_map, backward_map; |
---|
851 | public: |
---|
852 | typedef T Value; |
---|
853 | typedef Edge Key; |
---|
854 | |
---|
855 | EdgeMap(const SubBidirGraphWrapperBase<_Graph, |
---|
856 | ForwardFilterMap, BackwardFilterMap>& g) : |
---|
857 | forward_map(*(g.graph)), backward_map(*(g.graph)) { } |
---|
858 | |
---|
859 | EdgeMap(const SubBidirGraphWrapperBase<_Graph, |
---|
860 | ForwardFilterMap, BackwardFilterMap>& g, T a) : |
---|
861 | forward_map(*(g.graph), a), backward_map(*(g.graph), a) { } |
---|
862 | |
---|
863 | void set(Edge e, T a) { |
---|
864 | if (!e.backward) |
---|
865 | forward_map.set(e, a); |
---|
866 | else |
---|
867 | backward_map.set(e, a); |
---|
868 | } |
---|
869 | |
---|
870 | // typename _Graph::template EdgeMap<T>::ConstReference |
---|
871 | // operator[](Edge e) const { |
---|
872 | // if (!e.backward) |
---|
873 | // return forward_map[e]; |
---|
874 | // else |
---|
875 | // return backward_map[e]; |
---|
876 | // } |
---|
877 | |
---|
878 | // typename _Graph::template EdgeMap<T>::Reference |
---|
879 | T operator[](Edge e) const { |
---|
880 | if (!e.backward) |
---|
881 | return forward_map[e]; |
---|
882 | else |
---|
883 | return backward_map[e]; |
---|
884 | } |
---|
885 | |
---|
886 | void update() { |
---|
887 | forward_map.update(); |
---|
888 | backward_map.update(); |
---|
889 | } |
---|
890 | }; |
---|
891 | |
---|
892 | }; |
---|
893 | |
---|
894 | |
---|
895 | ///\brief A wrapper for composing a subgraph of a |
---|
896 | /// bidirected graph made from a directed one. |
---|
897 | /// |
---|
898 | /// A wrapper for composing a subgraph of a |
---|
899 | /// bidirected graph made from a directed one. |
---|
900 | /// |
---|
901 | ///\warning Graph wrappers are in even more experimental state than the other |
---|
902 | ///parts of the lib. Use them at you own risk. |
---|
903 | /// |
---|
904 | /// Let \f$G=(V, A)\f$ be a directed graph and for each directed edge |
---|
905 | /// \f$e\in A\f$, let \f$\bar e\f$ denote the edge obtained by |
---|
906 | /// reversing its orientation. We are given moreover two bool valued |
---|
907 | /// maps on the edge-set, |
---|
908 | /// \f$forward\_filter\f$, and \f$backward\_filter\f$. |
---|
909 | /// SubBidirGraphWrapper implements the graph structure with node-set |
---|
910 | /// \f$V\f$ and edge-set |
---|
911 | /// \f$\{e : e\in A \mbox{ and } forward\_filter(e) \mbox{ is true}\}+\{\bar e : e\in A \mbox{ and } backward\_filter(e) \mbox{ is true}\}\f$. |
---|
912 | /// The purpose of writing + instead of union is because parallel |
---|
913 | /// edges can arise. (Similarly, antiparallel edges also can arise). |
---|
914 | /// In other words, a subgraph of the bidirected graph obtained, which |
---|
915 | /// is given by orienting the edges of the original graph in both directions. |
---|
916 | /// As the oppositely directed edges are logically different, |
---|
917 | /// the maps are able to attach different values for them. |
---|
918 | /// |
---|
919 | /// An example for such a construction is \c RevGraphWrapper where the |
---|
920 | /// forward_filter is everywhere false and the backward_filter is |
---|
921 | /// everywhere true. We note that for sake of efficiency, |
---|
922 | /// \c RevGraphWrapper is implemented in a different way. |
---|
923 | /// But BidirGraphWrapper is obtained from |
---|
924 | /// SubBidirGraphWrapper by considering everywhere true |
---|
925 | /// valued maps both for forward_filter and backward_filter. |
---|
926 | /// |
---|
927 | /// The most important application of SubBidirGraphWrapper |
---|
928 | /// is ResGraphWrapper, which stands for the residual graph in directed |
---|
929 | /// flow and circulation problems. |
---|
930 | /// As wrappers usually, the SubBidirGraphWrapper implements the |
---|
931 | /// above mentioned graph structure without its physical storage, |
---|
932 | /// that is the whole stuff is stored in constant memory. |
---|
933 | template<typename _Graph, |
---|
934 | typename ForwardFilterMap, typename BackwardFilterMap> |
---|
935 | class SubBidirGraphWrapper : |
---|
936 | public IterableGraphExtender< |
---|
937 | SubBidirGraphWrapperBase<_Graph, ForwardFilterMap, BackwardFilterMap> > { |
---|
938 | public: |
---|
939 | typedef _Graph Graph; |
---|
940 | typedef IterableGraphExtender< |
---|
941 | SubBidirGraphWrapperBase< |
---|
942 | _Graph, ForwardFilterMap, BackwardFilterMap> > Parent; |
---|
943 | protected: |
---|
944 | SubBidirGraphWrapper() { } |
---|
945 | public: |
---|
946 | SubBidirGraphWrapper(_Graph& _graph, ForwardFilterMap& _forward_filter, |
---|
947 | BackwardFilterMap& _backward_filter) { |
---|
948 | setGraph(_graph); |
---|
949 | setForwardFilterMap(_forward_filter); |
---|
950 | setBackwardFilterMap(_backward_filter); |
---|
951 | } |
---|
952 | }; |
---|
953 | |
---|
954 | |
---|
955 | |
---|
956 | ///\brief A wrapper for composing bidirected graph from a directed one. |
---|
957 | /// |
---|
958 | ///\warning Graph wrappers are in even more experimental state than the other |
---|
959 | ///parts of the lib. Use them at you own risk. |
---|
960 | /// |
---|
961 | /// A wrapper for composing bidirected graph from a directed one. |
---|
962 | /// A bidirected graph is composed over the directed one without physical |
---|
963 | /// storage. As the oppositely directed edges are logically different ones |
---|
964 | /// the maps are able to attach different values for them. |
---|
965 | template<typename Graph> |
---|
966 | class BidirGraphWrapper : |
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967 | public SubBidirGraphWrapper< |
---|
968 | Graph, |
---|
969 | ConstMap<typename Graph::Edge, bool>, |
---|
970 | ConstMap<typename Graph::Edge, bool> > { |
---|
971 | public: |
---|
972 | typedef SubBidirGraphWrapper< |
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973 | Graph, |
---|
974 | ConstMap<typename Graph::Edge, bool>, |
---|
975 | ConstMap<typename Graph::Edge, bool> > Parent; |
---|
976 | protected: |
---|
977 | ConstMap<typename Graph::Edge, bool> cm; |
---|
978 | |
---|
979 | BidirGraphWrapper() : Parent(), cm(true) { |
---|
980 | Parent::setForwardFilterMap(cm); |
---|
981 | Parent::setBackwardFilterMap(cm); |
---|
982 | } |
---|
983 | public: |
---|
984 | BidirGraphWrapper(Graph& _graph) : Parent(), cm(true) { |
---|
985 | Parent::setGraph(_graph); |
---|
986 | Parent::setForwardFilterMap(cm); |
---|
987 | Parent::setBackwardFilterMap(cm); |
---|
988 | } |
---|
989 | |
---|
990 | int edgeNum() const { |
---|
991 | return 2*this->graph->edgeNum(); |
---|
992 | } |
---|
993 | // KEEP_MAPS(Parent, BidirGraphWrapper); |
---|
994 | }; |
---|
995 | |
---|
996 | |
---|
997 | template<typename Graph, typename Number, |
---|
998 | typename CapacityMap, typename FlowMap> |
---|
999 | class ResForwardFilter { |
---|
1000 | // const Graph* graph; |
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1001 | const CapacityMap* capacity; |
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1002 | const FlowMap* flow; |
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1003 | public: |
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1004 | ResForwardFilter(/*const Graph& _graph, */ |
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1005 | const CapacityMap& _capacity, const FlowMap& _flow) : |
---|
1006 | /*graph(&_graph),*/ capacity(&_capacity), flow(&_flow) { } |
---|
1007 | ResForwardFilter() : /*graph(0),*/ capacity(0), flow(0) { } |
---|
1008 | void setCapacity(const CapacityMap& _capacity) { capacity=&_capacity; } |
---|
1009 | void setFlow(const FlowMap& _flow) { flow=&_flow; } |
---|
1010 | bool operator[](const typename Graph::Edge& e) const { |
---|
1011 | return (Number((*flow)[e]) < Number((*capacity)[e])); |
---|
1012 | } |
---|
1013 | }; |
---|
1014 | |
---|
1015 | template<typename Graph, typename Number, |
---|
1016 | typename CapacityMap, typename FlowMap> |
---|
1017 | class ResBackwardFilter { |
---|
1018 | const CapacityMap* capacity; |
---|
1019 | const FlowMap* flow; |
---|
1020 | public: |
---|
1021 | ResBackwardFilter(/*const Graph& _graph,*/ |
---|
1022 | const CapacityMap& _capacity, const FlowMap& _flow) : |
---|
1023 | /*graph(&_graph),*/ capacity(&_capacity), flow(&_flow) { } |
---|
1024 | ResBackwardFilter() : /*graph(0),*/ capacity(0), flow(0) { } |
---|
1025 | void setCapacity(const CapacityMap& _capacity) { capacity=&_capacity; } |
---|
1026 | void setFlow(const FlowMap& _flow) { flow=&_flow; } |
---|
1027 | bool operator[](const typename Graph::Edge& e) const { |
---|
1028 | return (Number(0) < Number((*flow)[e])); |
---|
1029 | } |
---|
1030 | }; |
---|
1031 | |
---|
1032 | |
---|
1033 | /*! \brief A wrapper for composing the residual graph for directed flow and circulation problems. |
---|
1034 | |
---|
1035 | A wrapper for composing the residual graph for directed flow and circulation problems. |
---|
1036 | Let \f$G=(V, A)\f$ be a directed graph and let \f$F\f$ be a |
---|
1037 | number type. Let moreover |
---|
1038 | \f$f,c:A\to F\f$, be functions on the edge-set. |
---|
1039 | In the appications of ResGraphWrapper, \f$f\f$ usually stands for a flow |
---|
1040 | and \f$c\f$ for a capacity function. |
---|
1041 | Suppose that a graph instange \c g of type |
---|
1042 | \c ListGraph implements \f$G\f$. |
---|
1043 | \code |
---|
1044 | ListGraph g; |
---|
1045 | \endcode |
---|
1046 | Then RevGraphWrapper implements the graph structure with node-set |
---|
1047 | \f$V\f$ and edge-set \f$A_{forward}\cup A_{backward}\f$, where |
---|
1048 | \f$A_{forward}=\{uv : uv\in A, f(uv)<c(uv)\}\f$ and |
---|
1049 | \f$A_{backward}=\{vu : uv\in A, f(uv)>0\}\f$, |
---|
1050 | i.e. the so called residual graph. |
---|
1051 | When we take the union \f$A_{forward}\cup A_{backward}\f$, |
---|
1052 | multilicities are counted, i.e. if an edge is in both |
---|
1053 | \f$A_{forward}\f$ and \f$A_{backward}\f$, then in the wrapper it |
---|
1054 | appears twice. |
---|
1055 | The following code shows how |
---|
1056 | such an instance can be constructed. |
---|
1057 | \code |
---|
1058 | typedef ListGraph Graph; |
---|
1059 | Graph::EdgeMap<int> f(g); |
---|
1060 | Graph::EdgeMap<int> c(g); |
---|
1061 | ResGraphWrapper<Graph, int, Graph::EdgeMap<int>, Graph::EdgeMap<int> > gw(g); |
---|
1062 | \endcode |
---|
1063 | \author Marton Makai |
---|
1064 | */ |
---|
1065 | template<typename Graph, typename Number, |
---|
1066 | typename CapacityMap, typename FlowMap> |
---|
1067 | class ResGraphWrapper : |
---|
1068 | public SubBidirGraphWrapper< |
---|
1069 | Graph, |
---|
1070 | ResForwardFilter<Graph, Number, CapacityMap, FlowMap>, |
---|
1071 | ResBackwardFilter<Graph, Number, CapacityMap, FlowMap> > { |
---|
1072 | public: |
---|
1073 | typedef SubBidirGraphWrapper< |
---|
1074 | Graph, |
---|
1075 | ResForwardFilter<Graph, Number, CapacityMap, FlowMap>, |
---|
1076 | ResBackwardFilter<Graph, Number, CapacityMap, FlowMap> > Parent; |
---|
1077 | protected: |
---|
1078 | const CapacityMap* capacity; |
---|
1079 | FlowMap* flow; |
---|
1080 | ResForwardFilter<Graph, Number, CapacityMap, FlowMap> forward_filter; |
---|
1081 | ResBackwardFilter<Graph, Number, CapacityMap, FlowMap> backward_filter; |
---|
1082 | ResGraphWrapper() : Parent(), |
---|
1083 | capacity(0), flow(0) { } |
---|
1084 | void setCapacityMap(const CapacityMap& _capacity) { |
---|
1085 | capacity=&_capacity; |
---|
1086 | forward_filter.setCapacity(_capacity); |
---|
1087 | backward_filter.setCapacity(_capacity); |
---|
1088 | } |
---|
1089 | void setFlowMap(FlowMap& _flow) { |
---|
1090 | flow=&_flow; |
---|
1091 | forward_filter.setFlow(_flow); |
---|
1092 | backward_filter.setFlow(_flow); |
---|
1093 | } |
---|
1094 | public: |
---|
1095 | ResGraphWrapper(Graph& _graph, const CapacityMap& _capacity, |
---|
1096 | FlowMap& _flow) : |
---|
1097 | Parent(), capacity(&_capacity), flow(&_flow), |
---|
1098 | forward_filter(/*_graph,*/ _capacity, _flow), |
---|
1099 | backward_filter(/*_graph,*/ _capacity, _flow) { |
---|
1100 | Parent::setGraph(_graph); |
---|
1101 | Parent::setForwardFilterMap(forward_filter); |
---|
1102 | Parent::setBackwardFilterMap(backward_filter); |
---|
1103 | } |
---|
1104 | |
---|
1105 | typedef typename Parent::Edge Edge; |
---|
1106 | |
---|
1107 | void augment(const Edge& e, Number a) const { |
---|
1108 | if (Parent::forward(e)) |
---|
1109 | flow->set(e, (*flow)[e]+a); |
---|
1110 | else |
---|
1111 | flow->set(e, (*flow)[e]-a); |
---|
1112 | } |
---|
1113 | |
---|
1114 | /// \brief Residual capacity map. |
---|
1115 | /// |
---|
1116 | /// In generic residual graphs the residual capacity can be obtained |
---|
1117 | /// as a map. |
---|
1118 | class ResCap { |
---|
1119 | protected: |
---|
1120 | const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>* res_graph; |
---|
1121 | public: |
---|
1122 | typedef Number Value; |
---|
1123 | typedef Edge Key; |
---|
1124 | ResCap(const ResGraphWrapper<Graph, Number, CapacityMap, FlowMap>& |
---|
1125 | _res_graph) : res_graph(&_res_graph) { } |
---|
1126 | Number operator[](const Edge& e) const { |
---|
1127 | if (res_graph->forward(e)) |
---|
1128 | return (*(res_graph->capacity))[e]-(*(res_graph->flow))[e]; |
---|
1129 | else |
---|
1130 | return (*(res_graph->flow))[e]; |
---|
1131 | } |
---|
1132 | }; |
---|
1133 | |
---|
1134 | // KEEP_MAPS(Parent, ResGraphWrapper); |
---|
1135 | }; |
---|
1136 | |
---|
1137 | |
---|
1138 | |
---|
1139 | template <typename _Graph, typename FirstOutEdgesMap> |
---|
1140 | class ErasingFirstGraphWrapperBase : public GraphWrapperBase<_Graph> { |
---|
1141 | public: |
---|
1142 | typedef _Graph Graph; |
---|
1143 | typedef GraphWrapperBase<_Graph> Parent; |
---|
1144 | protected: |
---|
1145 | FirstOutEdgesMap* first_out_edges; |
---|
1146 | ErasingFirstGraphWrapperBase() : Parent(), |
---|
1147 | first_out_edges(0) { } |
---|
1148 | |
---|
1149 | void setFirstOutEdgesMap(FirstOutEdgesMap& _first_out_edges) { |
---|
1150 | first_out_edges=&_first_out_edges; |
---|
1151 | } |
---|
1152 | |
---|
1153 | public: |
---|
1154 | |
---|
1155 | typedef typename Parent::Node Node; |
---|
1156 | typedef typename Parent::Edge Edge; |
---|
1157 | |
---|
1158 | void firstOut(Edge& i, const Node& n) const { |
---|
1159 | i=(*first_out_edges)[n]; |
---|
1160 | } |
---|
1161 | |
---|
1162 | void erase(const Edge& e) const { |
---|
1163 | Node n=source(e); |
---|
1164 | Edge f=e; |
---|
1165 | Parent::nextOut(f); |
---|
1166 | first_out_edges->set(n, f); |
---|
1167 | } |
---|
1168 | }; |
---|
1169 | |
---|
1170 | |
---|
1171 | /// For blocking flows. |
---|
1172 | |
---|
1173 | ///\warning Graph wrappers are in even more experimental state than the other |
---|
1174 | ///parts of the lib. Use them at you own risk. |
---|
1175 | /// |
---|
1176 | /// This graph wrapper is used for on-the-fly |
---|
1177 | /// Dinits blocking flow computations. |
---|
1178 | /// For each node, an out-edge is stored which is used when the |
---|
1179 | /// \code |
---|
1180 | /// OutEdgeIt& first(OutEdgeIt&, const Node&) |
---|
1181 | /// \endcode |
---|
1182 | /// is called. |
---|
1183 | /// |
---|
1184 | /// \author Marton Makai |
---|
1185 | template <typename _Graph, typename FirstOutEdgesMap> |
---|
1186 | class ErasingFirstGraphWrapper : |
---|
1187 | public IterableGraphExtender< |
---|
1188 | ErasingFirstGraphWrapperBase<_Graph, FirstOutEdgesMap> > { |
---|
1189 | public: |
---|
1190 | typedef _Graph Graph; |
---|
1191 | typedef IterableGraphExtender< |
---|
1192 | ErasingFirstGraphWrapperBase<_Graph, FirstOutEdgesMap> > Parent; |
---|
1193 | ErasingFirstGraphWrapper(Graph& _graph, |
---|
1194 | FirstOutEdgesMap& _first_out_edges) { |
---|
1195 | setGraph(_graph); |
---|
1196 | setFirstOutEdgesMap(_first_out_edges); |
---|
1197 | } |
---|
1198 | |
---|
1199 | }; |
---|
1200 | |
---|
1201 | ///@} |
---|
1202 | |
---|
1203 | } //namespace lemon |
---|
1204 | |
---|
1205 | #endif //LEMON_GRAPH_WRAPPER_H |
---|
1206 | |
---|