1 | // -*- c++ -*- |
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2 | #ifndef EDMONDS_KARP_H |
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3 | #define EDMONDS_KARP_H |
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4 | |
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5 | #include <algorithm> |
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6 | #include <list> |
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7 | #include <iterator> |
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8 | |
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9 | #include <bfs_iterator.h> |
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10 | #include <invalid.h> |
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11 | |
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12 | namespace hugo { |
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13 | |
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14 | template<typename Graph, typename Number, typename FlowMap, typename CapacityMap> |
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15 | class ResGraph { |
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16 | public: |
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17 | typedef typename Graph::Node Node; |
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18 | typedef typename Graph::NodeIt NodeIt; |
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19 | private: |
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20 | typedef typename Graph::SymEdgeIt OldSymEdgeIt; |
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21 | const Graph& G; |
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22 | FlowMap& flow; |
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23 | const CapacityMap& capacity; |
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24 | public: |
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25 | ResGraph(const Graph& _G, FlowMap& _flow, |
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26 | const CapacityMap& _capacity) : |
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27 | G(_G), flow(_flow), capacity(_capacity) { } |
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28 | |
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29 | class Edge; |
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30 | class OutEdgeIt; |
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31 | friend class Edge; |
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32 | friend class OutEdgeIt; |
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33 | |
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34 | class Edge { |
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35 | friend class ResGraph<Graph, Number, FlowMap, CapacityMap>; |
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36 | protected: |
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37 | const ResGraph<Graph, Number, FlowMap, CapacityMap>* resG; |
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38 | OldSymEdgeIt sym; |
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39 | public: |
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40 | Edge() { } |
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41 | //Edge(const Edge& e) : resG(e.resG), sym(e.sym) { } |
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42 | Number free() const { |
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43 | if (resG->G.aNode(sym)==resG->G.tail(sym)) { |
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44 | return (resG->capacity.get(sym)-resG->flow.get(sym)); |
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45 | } else { |
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46 | return (resG->flow.get(sym)); |
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47 | } |
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48 | } |
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49 | bool valid() const { return sym.valid(); } |
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50 | void augment(Number a) const { |
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51 | if (resG->G.aNode(sym)==resG->G.tail(sym)) { |
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52 | resG->flow.set(sym, resG->flow.get(sym)+a); |
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53 | //resG->flow[sym]+=a; |
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54 | } else { |
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55 | resG->flow.set(sym, resG->flow.get(sym)-a); |
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56 | //resG->flow[sym]-=a; |
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57 | } |
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58 | } |
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59 | }; |
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60 | |
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61 | class OutEdgeIt : public Edge { |
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62 | friend class ResGraph<Graph, Number, FlowMap, CapacityMap>; |
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63 | public: |
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64 | OutEdgeIt() { } |
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65 | //OutEdgeIt(const OutEdgeIt& e) { resG=e.resG; sym=e.sym; } |
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66 | private: |
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67 | OutEdgeIt(const ResGraph<Graph, Number, FlowMap, CapacityMap>& _resG, Node v) { |
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68 | resG=&_resG; |
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69 | sym=resG->G.template first<OldSymEdgeIt>(v); |
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70 | while( sym.valid() && !(free()>0) ) { ++sym; } |
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71 | } |
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72 | public: |
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73 | OutEdgeIt& operator++() { |
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74 | ++sym; |
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75 | while( sym.valid() && !(free()>0) ) { ++sym; } |
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76 | return *this; |
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77 | } |
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78 | }; |
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79 | |
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80 | void /*getF*/first(OutEdgeIt& e, Node v) const { |
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81 | e=OutEdgeIt(*this, v); |
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82 | } |
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83 | void /*getF*/first(NodeIt& v) const { G./*getF*/first(v); } |
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84 | |
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85 | template< typename It > |
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86 | It first() const { |
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87 | It e; |
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88 | /*getF*/first(e); |
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89 | return e; |
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90 | } |
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91 | |
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92 | template< typename It > |
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93 | It first(Node v) const { |
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94 | It e; |
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95 | /*getF*/first(e, v); |
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96 | return e; |
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97 | } |
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98 | |
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99 | Node tail(Edge e) const { return G.aNode(e.sym); } |
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100 | Node head(Edge e) const { return G.bNode(e.sym); } |
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101 | |
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102 | Node aNode(OutEdgeIt e) const { return G.aNode(e.sym); } |
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103 | Node bNode(OutEdgeIt e) const { return G.bNode(e.sym); } |
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104 | |
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105 | int id(Node v) const { return G.id(v); } |
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106 | |
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107 | template <typename S> |
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108 | class NodeMap { |
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109 | typename Graph::NodeMap<S> node_map; |
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110 | public: |
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111 | NodeMap(const ResGraph<Graph, Number, FlowMap, CapacityMap>& _G) : node_map(_G.G) { } |
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112 | NodeMap(const ResGraph<Graph, Number, FlowMap, CapacityMap>& _G, S a) : node_map(_G.G, a) { } |
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113 | void set(Node nit, S a) { node_map.set(nit, a); } |
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114 | S get(Node nit) const { return node_map.get(nit); } |
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115 | S& operator[](Node nit) { return node_map[nit]; } |
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116 | const S& operator[](Node nit) const { return node_map[nit]; } |
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117 | }; |
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118 | |
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119 | }; |
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120 | |
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121 | |
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122 | template<typename Graph, typename Number, typename FlowMap, typename CapacityMap> |
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123 | class ResGraph2 { |
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124 | public: |
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125 | typedef typename Graph::Node Node; |
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126 | typedef typename Graph::NodeIt NodeIt; |
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127 | private: |
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128 | //typedef typename Graph::SymEdgeIt OldSymEdgeIt; |
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129 | typedef typename Graph::OutEdgeIt OldOutEdgeIt; |
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130 | typedef typename Graph::InEdgeIt OldInEdgeIt; |
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131 | |
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132 | const Graph& G; |
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133 | FlowMap& flow; |
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134 | const CapacityMap& capacity; |
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135 | public: |
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136 | ResGraph2(const Graph& _G, FlowMap& _flow, |
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137 | const CapacityMap& _capacity) : |
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138 | G(_G), flow(_flow), capacity(_capacity) { } |
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139 | |
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140 | class Edge; |
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141 | class OutEdgeIt; |
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142 | friend class Edge; |
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143 | friend class OutEdgeIt; |
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144 | |
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145 | class Edge { |
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146 | friend class ResGraph2<Graph, Number, FlowMap, CapacityMap>; |
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147 | protected: |
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148 | const ResGraph2<Graph, Number, FlowMap, CapacityMap>* resG; |
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149 | //OldSymEdgeIt sym; |
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150 | OldOutEdgeIt out; |
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151 | OldInEdgeIt in; |
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152 | bool out_or_in; //true, iff out |
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153 | public: |
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154 | Edge() : out_or_in(true) { } |
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155 | Number free() const { |
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156 | if (out_or_in) { |
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157 | return (resG->capacity.get(out)-resG->flow.get(out)); |
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158 | } else { |
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159 | return (resG->flow.get(in)); |
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160 | } |
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161 | } |
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162 | bool valid() const { |
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163 | return out_or_in && out.valid() || in.valid(); } |
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164 | void augment(Number a) const { |
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165 | if (out_or_in) { |
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166 | resG->flow.set(out, resG->flow.get(out)+a); |
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167 | } else { |
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168 | resG->flow.set(in, resG->flow.get(in)-a); |
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169 | } |
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170 | } |
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171 | }; |
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172 | |
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173 | class OutEdgeIt : public Edge { |
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174 | friend class ResGraph2<Graph, Number, FlowMap, CapacityMap>; |
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175 | public: |
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176 | OutEdgeIt() { } |
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177 | private: |
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178 | OutEdgeIt(const ResGraph2<Graph, Number, FlowMap, CapacityMap>& _resG, Node v) { |
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179 | resG=&_resG; |
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180 | out=resG->G.template first<OldOutEdgeIt>(v); |
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181 | while( out.valid() && !(free()>0) ) { ++out; } |
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182 | if (!out.valid()) { |
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183 | out_or_in=0; |
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184 | in=resG->G.template first<OldInEdgeIt>(v); |
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185 | while( in.valid() && !(free()>0) ) { ++in; } |
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186 | } |
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187 | } |
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188 | public: |
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189 | OutEdgeIt& operator++() { |
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190 | if (out_or_in) { |
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191 | Node v=resG->G.aNode(out); |
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192 | ++out; |
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193 | while( out.valid() && !(free()>0) ) { ++out; } |
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194 | if (!out.valid()) { |
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195 | out_or_in=0; |
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196 | in=resG->G.template first<OldInEdgeIt>(v); |
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197 | while( in.valid() && !(free()>0) ) { ++in; } |
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198 | } |
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199 | } else { |
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200 | ++in; |
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201 | while( in.valid() && !(free()>0) ) { ++in; } |
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202 | } |
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203 | return *this; |
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204 | } |
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205 | }; |
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206 | |
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207 | void /*getF*/first(OutEdgeIt& e, Node v) const { |
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208 | e=OutEdgeIt(*this, v); |
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209 | } |
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210 | void /*getF*/first(NodeIt& v) const { G./*getF*/first(v); } |
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211 | |
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212 | template< typename It > |
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213 | It first() const { |
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214 | It e; |
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215 | /*getF*/first(e); |
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216 | return e; |
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217 | } |
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218 | |
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219 | template< typename It > |
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220 | It first(Node v) const { |
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221 | It e; |
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222 | /*getF*/first(e, v); |
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223 | return e; |
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224 | } |
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225 | |
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226 | Node tail(Edge e) const { |
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227 | return ((e.out_or_in) ? G.aNode(e.out) : G.aNode(e.in)); } |
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228 | Node head(Edge e) const { |
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229 | return ((e.out_or_in) ? G.bNode(e.out) : G.bNode(e.in)); } |
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230 | |
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231 | Node aNode(OutEdgeIt e) const { |
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232 | return ((e.out_or_in) ? G.aNode(e.out) : G.aNode(e.in)); } |
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233 | Node bNode(OutEdgeIt e) const { |
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234 | return ((e.out_or_in) ? G.bNode(e.out) : G.bNode(e.in)); } |
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235 | |
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236 | int id(Node v) const { return G.id(v); } |
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237 | |
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238 | template <typename S> |
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239 | class NodeMap { |
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240 | typename Graph::NodeMap<S> node_map; |
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241 | public: |
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242 | NodeMap(const ResGraph2<Graph, Number, FlowMap, CapacityMap>& _G) : node_map(_G.G) { } |
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243 | NodeMap(const ResGraph2<Graph, Number, FlowMap, CapacityMap>& _G, S a) : node_map(_G.G, a) { } |
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244 | void set(Node nit, S a) { node_map.set(nit, a); } |
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245 | S get(Node nit) const { return node_map.get(nit); } |
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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 | template <typename Graph, typename Number, typename FlowMap, typename CapacityMap> |
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251 | class MaxFlow { |
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252 | public: |
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253 | typedef typename Graph::Node Node; |
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254 | typedef typename Graph::Edge Edge; |
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255 | typedef typename Graph::EdgeIt EdgeIt; |
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256 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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257 | typedef typename Graph::InEdgeIt InEdgeIt; |
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258 | |
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259 | private: |
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260 | const Graph* G; |
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261 | Node s; |
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262 | Node t; |
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263 | FlowMap* flow; |
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264 | const CapacityMap* capacity; |
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265 | typedef ResGraphWrapper<Graph, Number, FlowMap, CapacityMap > AugGraph; |
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266 | typedef typename AugGraph::OutEdgeIt AugOutEdgeIt; |
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267 | typedef typename AugGraph::Edge AugEdge; |
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268 | |
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269 | public: |
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270 | MaxFlow(const Graph& _G, Node _s, Node _t, FlowMap& _flow, const CapacityMap& _capacity) : |
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271 | G(&_G), s(_s), t(_t), flow(&_flow), capacity(&_capacity) { } |
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272 | bool augmentOnShortestPath() { |
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273 | AugGraph res_graph(*G, *flow, *capacity); |
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274 | bool _augment=false; |
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275 | |
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276 | typedef typename AugGraph::NodeMap<bool> ReachedMap; |
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277 | BfsIterator5< AugGraph, /*AugOutEdgeIt,*/ ReachedMap > res_bfs(res_graph); |
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278 | res_bfs.pushAndSetReached(s); |
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279 | |
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280 | typename AugGraph::NodeMap<AugEdge> pred(res_graph); |
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281 | pred.set(s, AugEdge(INVALID)); |
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282 | |
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283 | typename AugGraph::NodeMap<Number> free(res_graph); |
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284 | |
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285 | //searching for augmenting path |
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286 | while ( !res_bfs.finished() ) { |
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287 | AugOutEdgeIt e=res_bfs; |
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288 | if (res_graph.valid(e) && res_bfs.isBNodeNewlyReached()) { |
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289 | Node v=res_graph.tail(e); |
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290 | Node w=res_graph.head(e); |
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291 | pred.set(w, e); |
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292 | if (res_graph.valid(pred.get(v))) { |
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293 | free.set(w, std::min(free.get(v), res_graph.free(e))); |
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294 | } else { |
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295 | free.set(w, res_graph.free(e)); |
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296 | } |
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297 | if (res_graph.head(e)==t) { _augment=true; break; } |
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298 | } |
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299 | |
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300 | ++res_bfs; |
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301 | } //end of searching augmenting path |
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302 | |
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303 | if (_augment) { |
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304 | Node n=t; |
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305 | Number augment_value=free.get(t); |
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306 | while (res_graph.valid(pred.get(n))) { |
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307 | AugEdge e=pred.get(n); |
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308 | res_graph.augment(e, augment_value); |
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309 | n=res_graph.tail(e); |
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310 | } |
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311 | } |
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312 | |
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313 | return _augment; |
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314 | } |
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315 | |
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316 | template<typename MutableGraph> bool augmentOnBlockingFlow() { |
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317 | bool _augment=false; |
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318 | |
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319 | AugGraph res_graph(*G, *flow, *capacity); |
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320 | |
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321 | typedef typename AugGraph::NodeMap<bool> ReachedMap; |
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322 | BfsIterator4< AugGraph, AugOutEdgeIt, ReachedMap > bfs(res_graph); |
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323 | |
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324 | bfs.pushAndSetReached(s); |
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325 | typename AugGraph::NodeMap<int> dist(res_graph); //filled up with 0's |
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326 | while ( !bfs.finished() ) { |
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327 | AugOutEdgeIt e=bfs; |
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328 | if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) { |
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329 | dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1); |
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330 | } |
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331 | |
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332 | ++bfs; |
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333 | } //computing distances from s in the residual graph |
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334 | |
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335 | MutableGraph F; |
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336 | typename AugGraph::NodeMap<typename MutableGraph::Node> |
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337 | res_graph_to_F(res_graph); |
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338 | for(typename AugGraph::NodeIt n=res_graph.template first<typename AugGraph::NodeIt>(); res_graph.valid(n); res_graph.next(n)) { |
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339 | res_graph_to_F.set(n, F.addNode()); |
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340 | } |
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341 | |
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342 | typename MutableGraph::Node sF=res_graph_to_F.get(s); |
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343 | typename MutableGraph::Node tF=res_graph_to_F.get(t); |
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344 | |
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345 | typename MutableGraph::EdgeMap<AugEdge> original_edge(F); |
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346 | typename MutableGraph::EdgeMap<Number> residual_capacity(F); |
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347 | |
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348 | //Making F to the graph containing the edges of the residual graph |
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349 | //which are in some shortest paths |
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350 | for(typename AugGraph::EdgeIt e=res_graph.template first<typename AugGraph::EdgeIt>(); res_graph.valid(e); res_graph.next(e)) { |
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351 | if (dist.get(res_graph.head(e))==dist.get(res_graph.tail(e))+1) { |
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352 | typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e))); |
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353 | original_edge.update(); |
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354 | original_edge.set(f, e); |
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355 | residual_capacity.update(); |
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356 | residual_capacity.set(f, res_graph.free(e)); |
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357 | } |
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358 | } |
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359 | |
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360 | bool __augment=true; |
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361 | |
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362 | while (__augment) { |
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363 | __augment=false; |
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364 | //computing blocking flow with dfs |
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365 | typedef typename MutableGraph::NodeMap<bool> BlockingReachedMap; |
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366 | DfsIterator4< MutableGraph, typename MutableGraph::OutEdgeIt, BlockingReachedMap > dfs(F); |
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367 | typename MutableGraph::NodeMap<typename MutableGraph::Edge> pred(F); |
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368 | pred.set(sF, typename MutableGraph::Edge(INVALID)); |
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369 | //invalid iterators for sources |
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370 | |
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371 | typename MutableGraph::NodeMap<Number> free(F); |
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372 | |
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373 | dfs.pushAndSetReached(sF); |
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374 | while (!dfs.finished()) { |
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375 | ++dfs; |
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376 | if (F.valid(typename MutableGraph::OutEdgeIt(dfs))) { |
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377 | if (dfs.isBNodeNewlyReached()) { |
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378 | typename MutableGraph::Node v=F.aNode(dfs); |
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379 | typename MutableGraph::Node w=F.bNode(dfs); |
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380 | pred.set(w, dfs); |
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381 | if (F.valid(pred.get(v))) { |
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382 | free.set(w, std::min(free.get(v), residual_capacity.get(dfs))); |
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383 | } else { |
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384 | free.set(w, residual_capacity.get(dfs)); |
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385 | } |
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386 | if (w==tF) { |
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387 | __augment=true; |
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388 | _augment=true; |
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389 | break; |
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390 | } |
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391 | |
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392 | } else { |
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393 | F.erase(typename MutableGraph::OutEdgeIt(dfs)); |
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394 | } |
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395 | } |
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396 | } |
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397 | |
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398 | if (__augment) { |
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399 | typename MutableGraph::Node n=tF; |
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400 | Number augment_value=free.get(tF); |
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401 | while (F.valid(pred.get(n))) { |
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402 | typename MutableGraph::Edge e=pred.get(n); |
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403 | res_graph.augment(original_edge.get(e), augment_value); |
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404 | n=F.tail(e); |
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405 | if (residual_capacity.get(e)==augment_value) |
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406 | F.erase(e); |
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407 | else |
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408 | residual_capacity.set(e, residual_capacity.get(e)-augment_value); |
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409 | } |
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410 | } |
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411 | |
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412 | } |
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413 | |
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414 | return _augment; |
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415 | } |
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416 | bool augmentOnBlockingFlow2() { |
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417 | bool _augment=false; |
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418 | |
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419 | //typedef ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap> EAugGraph; |
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420 | typedef FilterGraphWrapper< ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap> > EAugGraph; |
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421 | typedef typename EAugGraph::OutEdgeIt EAugOutEdgeIt; |
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422 | typedef typename EAugGraph::Edge EAugEdge; |
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423 | |
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424 | EAugGraph res_graph(*G, *flow, *capacity); |
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425 | |
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426 | //typedef typename EAugGraph::NodeMap<bool> ReachedMap; |
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427 | BfsIterator4< |
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428 | ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>, |
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429 | typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::OutEdgeIt, |
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430 | ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::NodeMap<bool> > bfs(res_graph); |
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431 | |
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432 | bfs.pushAndSetReached(s); |
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433 | |
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434 | typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>:: |
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435 | NodeMap<int>& dist=res_graph.dist; |
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436 | |
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437 | while ( !bfs.finished() ) { |
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438 | typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::OutEdgeIt e=bfs; |
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439 | if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) { |
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440 | dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1); |
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441 | } |
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442 | ++bfs; |
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443 | } //computing distances from s in the residual graph |
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444 | |
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445 | bool __augment=true; |
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446 | |
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447 | while (__augment) { |
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448 | |
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449 | __augment=false; |
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450 | //computing blocking flow with dfs |
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451 | typedef typename EAugGraph::NodeMap<bool> BlockingReachedMap; |
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452 | DfsIterator4< EAugGraph, EAugOutEdgeIt, BlockingReachedMap > |
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453 | dfs(res_graph); |
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454 | typename EAugGraph::NodeMap<EAugEdge> pred(res_graph); |
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455 | pred.set(s, EAugEdge(INVALID)); |
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456 | //invalid iterators for sources |
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457 | |
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458 | typename EAugGraph::NodeMap<Number> free(res_graph); |
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459 | |
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460 | dfs.pushAndSetReached(s); |
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461 | while (!dfs.finished()) { |
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462 | ++dfs; |
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463 | if (res_graph.valid(EAugOutEdgeIt(dfs))) { |
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464 | if (dfs.isBNodeNewlyReached()) { |
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465 | |
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466 | typename EAugGraph::Node v=res_graph.aNode(dfs); |
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467 | typename EAugGraph::Node w=res_graph.bNode(dfs); |
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468 | |
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469 | pred.set(w, EAugOutEdgeIt(dfs)); |
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470 | if (res_graph.valid(pred.get(v))) { |
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471 | free.set(w, std::min(free.get(v), res_graph.free(dfs))); |
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472 | } else { |
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473 | free.set(w, res_graph.free(dfs)); |
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474 | } |
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475 | |
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476 | if (w==t) { |
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477 | __augment=true; |
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478 | _augment=true; |
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479 | break; |
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480 | } |
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481 | } else { |
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482 | res_graph.erase(dfs); |
---|
483 | } |
---|
484 | } |
---|
485 | |
---|
486 | } |
---|
487 | |
---|
488 | if (__augment) { |
---|
489 | typename EAugGraph::Node n=t; |
---|
490 | Number augment_value=free.get(t); |
---|
491 | while (res_graph.valid(pred.get(n))) { |
---|
492 | EAugEdge e=pred.get(n); |
---|
493 | res_graph.augment(e, augment_value); |
---|
494 | n=res_graph.tail(e); |
---|
495 | if (res_graph.free(e)==0) |
---|
496 | res_graph.erase(e); |
---|
497 | } |
---|
498 | } |
---|
499 | |
---|
500 | } |
---|
501 | |
---|
502 | return _augment; |
---|
503 | } |
---|
504 | void run() { |
---|
505 | //int num_of_augmentations=0; |
---|
506 | while (augmentOnShortestPath()) { |
---|
507 | //while (augmentOnBlockingFlow<MutableGraph>()) { |
---|
508 | //std::cout << ++num_of_augmentations << " "; |
---|
509 | //std::cout<<std::endl; |
---|
510 | } |
---|
511 | } |
---|
512 | template<typename MutableGraph> void run() { |
---|
513 | //int num_of_augmentations=0; |
---|
514 | //while (augmentOnShortestPath()) { |
---|
515 | while (augmentOnBlockingFlow<MutableGraph>()) { |
---|
516 | //std::cout << ++num_of_augmentations << " "; |
---|
517 | //std::cout<<std::endl; |
---|
518 | } |
---|
519 | } |
---|
520 | Number flowValue() { |
---|
521 | Number a=0; |
---|
522 | OutEdgeIt e; |
---|
523 | for(G->/*getF*/first(e, s); G->valid(e); G->next(e)) { |
---|
524 | a+=flow->get(e); |
---|
525 | } |
---|
526 | return a; |
---|
527 | } |
---|
528 | }; |
---|
529 | |
---|
530 | |
---|
531 | template <typename Graph, typename Number, typename FlowMap, typename CapacityMap> |
---|
532 | class MaxMatching { |
---|
533 | public: |
---|
534 | typedef typename Graph::Node Node; |
---|
535 | typedef typename Graph::Edge Edge; |
---|
536 | typedef typename Graph::EdgeIt EdgeIt; |
---|
537 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
538 | typedef typename Graph::InEdgeIt InEdgeIt; |
---|
539 | |
---|
540 | typedef typename Graph::NodeMap<bool> SMap; |
---|
541 | typedef typename Graph::NodeMap<bool> TMap; |
---|
542 | private: |
---|
543 | const Graph* G; |
---|
544 | SMap* S; |
---|
545 | TMap* T; |
---|
546 | //Node s; |
---|
547 | //Node t; |
---|
548 | FlowMap* flow; |
---|
549 | const CapacityMap* capacity; |
---|
550 | typedef ResGraphWrapper<Graph, Number, FlowMap, CapacityMap > AugGraph; |
---|
551 | typedef typename AugGraph::OutEdgeIt AugOutEdgeIt; |
---|
552 | typedef typename AugGraph::Edge AugEdge; |
---|
553 | |
---|
554 | public: |
---|
555 | MaxMatching(const Graph& _G, SMap& _S, TMap& _T, FlowMap& _flow, const CapacityMap& _capacity) : |
---|
556 | G(&_G), S(&_S), T(&_T), flow(&_flow), capacity(&_capacity) { } |
---|
557 | bool augmentOnShortestPath() { |
---|
558 | AugGraph res_graph(*G, *flow, *capacity); |
---|
559 | bool _augment=false; |
---|
560 | |
---|
561 | typedef typename AugGraph::NodeMap<bool> ReachedMap; |
---|
562 | BfsIterator5< AugGraph, /*AugOutEdgeIt,*/ ReachedMap > res_bfs(res_graph); |
---|
563 | typename AugGraph::NodeMap<AugEdge> pred(res_graph); |
---|
564 | for(NodeIt s=G->template first<NodeIt>(); G->valid(s); G->next(s)) { |
---|
565 | Number f=0; |
---|
566 | for(OutEdgeIt e=G->template first<OutEdgeIt>(); G->valid(e); G->next(e)) |
---|
567 | f+=flow->get(e); |
---|
568 | if (f<1) { |
---|
569 | res_bfs.pushAndSetReached(s); |
---|
570 | pred.set(s, AugEdge(INVALID)); |
---|
571 | } |
---|
572 | } |
---|
573 | |
---|
574 | typename AugGraph::NodeMap<Number> free(res_graph); |
---|
575 | |
---|
576 | Node n; |
---|
577 | //searching for augmenting path |
---|
578 | while ( !res_bfs.finished() ) { |
---|
579 | AugOutEdgeIt e=res_bfs; |
---|
580 | if (res_graph.valid(e) && res_bfs.isBNodeNewlyReached()) { |
---|
581 | Node v=res_graph.tail(e); |
---|
582 | Node w=res_graph.head(e); |
---|
583 | pred.set(w, e); |
---|
584 | if (res_graph.valid(pred.get(v))) { |
---|
585 | free.set(w, std::min(free.get(v), res_graph.free(e))); |
---|
586 | } else { |
---|
587 | free.set(w, res_graph.free(e)); |
---|
588 | } |
---|
589 | if (TMap(res_graph.head(e))) { |
---|
590 | n=res_graph.head(e); |
---|
591 | _augment=true; |
---|
592 | break; |
---|
593 | } |
---|
594 | } |
---|
595 | |
---|
596 | ++res_bfs; |
---|
597 | } //end of searching augmenting path |
---|
598 | |
---|
599 | if (_augment) { |
---|
600 | //Node n=t; |
---|
601 | Number augment_value=free.get(t); |
---|
602 | while (res_graph.valid(pred.get(n))) { |
---|
603 | AugEdge e=pred.get(n); |
---|
604 | res_graph.augment(e, augment_value); |
---|
605 | n=res_graph.tail(e); |
---|
606 | } |
---|
607 | } |
---|
608 | |
---|
609 | return _augment; |
---|
610 | } |
---|
611 | |
---|
612 | // template<typename MutableGraph> bool augmentOnBlockingFlow() { |
---|
613 | // bool _augment=false; |
---|
614 | |
---|
615 | // AugGraph res_graph(*G, *flow, *capacity); |
---|
616 | |
---|
617 | // typedef typename AugGraph::NodeMap<bool> ReachedMap; |
---|
618 | // BfsIterator4< AugGraph, AugOutEdgeIt, ReachedMap > bfs(res_graph); |
---|
619 | |
---|
620 | // bfs.pushAndSetReached(s); |
---|
621 | // typename AugGraph::NodeMap<int> dist(res_graph); //filled up with 0's |
---|
622 | // while ( !bfs.finished() ) { |
---|
623 | // AugOutEdgeIt e=bfs; |
---|
624 | // if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) { |
---|
625 | // dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1); |
---|
626 | // } |
---|
627 | |
---|
628 | // ++bfs; |
---|
629 | // } //computing distances from s in the residual graph |
---|
630 | |
---|
631 | // MutableGraph F; |
---|
632 | // typename AugGraph::NodeMap<typename MutableGraph::Node> |
---|
633 | // res_graph_to_F(res_graph); |
---|
634 | // for(typename AugGraph::NodeIt n=res_graph.template first<typename AugGraph::NodeIt>(); res_graph.valid(n); res_graph.next(n)) { |
---|
635 | // res_graph_to_F.set(n, F.addNode()); |
---|
636 | // } |
---|
637 | |
---|
638 | // typename MutableGraph::Node sF=res_graph_to_F.get(s); |
---|
639 | // typename MutableGraph::Node tF=res_graph_to_F.get(t); |
---|
640 | |
---|
641 | // typename MutableGraph::EdgeMap<AugEdge> original_edge(F); |
---|
642 | // typename MutableGraph::EdgeMap<Number> residual_capacity(F); |
---|
643 | |
---|
644 | // //Making F to the graph containing the edges of the residual graph |
---|
645 | // //which are in some shortest paths |
---|
646 | // for(typename AugGraph::EdgeIt e=res_graph.template first<typename AugGraph::EdgeIt>(); res_graph.valid(e); res_graph.next(e)) { |
---|
647 | // if (dist.get(res_graph.head(e))==dist.get(res_graph.tail(e))+1) { |
---|
648 | // typename MutableGraph::Edge f=F.addEdge(res_graph_to_F.get(res_graph.tail(e)), res_graph_to_F.get(res_graph.head(e))); |
---|
649 | // original_edge.update(); |
---|
650 | // original_edge.set(f, e); |
---|
651 | // residual_capacity.update(); |
---|
652 | // residual_capacity.set(f, res_graph.free(e)); |
---|
653 | // } |
---|
654 | // } |
---|
655 | |
---|
656 | // bool __augment=true; |
---|
657 | |
---|
658 | // while (__augment) { |
---|
659 | // __augment=false; |
---|
660 | // //computing blocking flow with dfs |
---|
661 | // typedef typename MutableGraph::NodeMap<bool> BlockingReachedMap; |
---|
662 | // DfsIterator4< MutableGraph, typename MutableGraph::OutEdgeIt, BlockingReachedMap > dfs(F); |
---|
663 | // typename MutableGraph::NodeMap<typename MutableGraph::Edge> pred(F); |
---|
664 | // pred.set(sF, typename MutableGraph::Edge(INVALID)); |
---|
665 | // //invalid iterators for sources |
---|
666 | |
---|
667 | // typename MutableGraph::NodeMap<Number> free(F); |
---|
668 | |
---|
669 | // dfs.pushAndSetReached(sF); |
---|
670 | // while (!dfs.finished()) { |
---|
671 | // ++dfs; |
---|
672 | // if (F.valid(typename MutableGraph::OutEdgeIt(dfs))) { |
---|
673 | // if (dfs.isBNodeNewlyReached()) { |
---|
674 | // typename MutableGraph::Node v=F.aNode(dfs); |
---|
675 | // typename MutableGraph::Node w=F.bNode(dfs); |
---|
676 | // pred.set(w, dfs); |
---|
677 | // if (F.valid(pred.get(v))) { |
---|
678 | // free.set(w, std::min(free.get(v), residual_capacity.get(dfs))); |
---|
679 | // } else { |
---|
680 | // free.set(w, residual_capacity.get(dfs)); |
---|
681 | // } |
---|
682 | // if (w==tF) { |
---|
683 | // __augment=true; |
---|
684 | // _augment=true; |
---|
685 | // break; |
---|
686 | // } |
---|
687 | |
---|
688 | // } else { |
---|
689 | // F.erase(typename MutableGraph::OutEdgeIt(dfs)); |
---|
690 | // } |
---|
691 | // } |
---|
692 | // } |
---|
693 | |
---|
694 | // if (__augment) { |
---|
695 | // typename MutableGraph::Node n=tF; |
---|
696 | // Number augment_value=free.get(tF); |
---|
697 | // while (F.valid(pred.get(n))) { |
---|
698 | // typename MutableGraph::Edge e=pred.get(n); |
---|
699 | // res_graph.augment(original_edge.get(e), augment_value); |
---|
700 | // n=F.tail(e); |
---|
701 | // if (residual_capacity.get(e)==augment_value) |
---|
702 | // F.erase(e); |
---|
703 | // else |
---|
704 | // residual_capacity.set(e, residual_capacity.get(e)-augment_value); |
---|
705 | // } |
---|
706 | // } |
---|
707 | |
---|
708 | // } |
---|
709 | |
---|
710 | // return _augment; |
---|
711 | // } |
---|
712 | // bool augmentOnBlockingFlow2() { |
---|
713 | // bool _augment=false; |
---|
714 | |
---|
715 | // //typedef ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap> EAugGraph; |
---|
716 | // typedef FilterGraphWrapper< ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap> > EAugGraph; |
---|
717 | // typedef typename EAugGraph::OutEdgeIt EAugOutEdgeIt; |
---|
718 | // typedef typename EAugGraph::Edge EAugEdge; |
---|
719 | |
---|
720 | // EAugGraph res_graph(*G, *flow, *capacity); |
---|
721 | |
---|
722 | // //typedef typename EAugGraph::NodeMap<bool> ReachedMap; |
---|
723 | // BfsIterator4< |
---|
724 | // ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>, |
---|
725 | // typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::OutEdgeIt, |
---|
726 | // ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::NodeMap<bool> > bfs(res_graph); |
---|
727 | |
---|
728 | // bfs.pushAndSetReached(s); |
---|
729 | |
---|
730 | // typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>:: |
---|
731 | // NodeMap<int>& dist=res_graph.dist; |
---|
732 | |
---|
733 | // while ( !bfs.finished() ) { |
---|
734 | // typename ErasingResGraphWrapper<Graph, Number, FlowMap, CapacityMap>::OutEdgeIt e=bfs; |
---|
735 | // if (res_graph.valid(e) && bfs.isBNodeNewlyReached()) { |
---|
736 | // dist.set(res_graph.head(e), dist.get(res_graph.tail(e))+1); |
---|
737 | // } |
---|
738 | // ++bfs; |
---|
739 | // } //computing distances from s in the residual graph |
---|
740 | |
---|
741 | // bool __augment=true; |
---|
742 | |
---|
743 | // while (__augment) { |
---|
744 | |
---|
745 | // __augment=false; |
---|
746 | // //computing blocking flow with dfs |
---|
747 | // typedef typename EAugGraph::NodeMap<bool> BlockingReachedMap; |
---|
748 | // DfsIterator4< EAugGraph, EAugOutEdgeIt, BlockingReachedMap > |
---|
749 | // dfs(res_graph); |
---|
750 | // typename EAugGraph::NodeMap<EAugEdge> pred(res_graph); |
---|
751 | // pred.set(s, EAugEdge(INVALID)); |
---|
752 | // //invalid iterators for sources |
---|
753 | |
---|
754 | // typename EAugGraph::NodeMap<Number> free(res_graph); |
---|
755 | |
---|
756 | // dfs.pushAndSetReached(s); |
---|
757 | // while (!dfs.finished()) { |
---|
758 | // ++dfs; |
---|
759 | // if (res_graph.valid(EAugOutEdgeIt(dfs))) { |
---|
760 | // if (dfs.isBNodeNewlyReached()) { |
---|
761 | |
---|
762 | // typename EAugGraph::Node v=res_graph.aNode(dfs); |
---|
763 | // typename EAugGraph::Node w=res_graph.bNode(dfs); |
---|
764 | |
---|
765 | // pred.set(w, EAugOutEdgeIt(dfs)); |
---|
766 | // if (res_graph.valid(pred.get(v))) { |
---|
767 | // free.set(w, std::min(free.get(v), res_graph.free(dfs))); |
---|
768 | // } else { |
---|
769 | // free.set(w, res_graph.free(dfs)); |
---|
770 | // } |
---|
771 | |
---|
772 | // if (w==t) { |
---|
773 | // __augment=true; |
---|
774 | // _augment=true; |
---|
775 | // break; |
---|
776 | // } |
---|
777 | // } else { |
---|
778 | // res_graph.erase(dfs); |
---|
779 | // } |
---|
780 | // } |
---|
781 | |
---|
782 | // } |
---|
783 | |
---|
784 | // if (__augment) { |
---|
785 | // typename EAugGraph::Node n=t; |
---|
786 | // Number augment_value=free.get(t); |
---|
787 | // while (res_graph.valid(pred.get(n))) { |
---|
788 | // EAugEdge e=pred.get(n); |
---|
789 | // res_graph.augment(e, augment_value); |
---|
790 | // n=res_graph.tail(e); |
---|
791 | // if (res_graph.free(e)==0) |
---|
792 | // res_graph.erase(e); |
---|
793 | // } |
---|
794 | // } |
---|
795 | |
---|
796 | // } |
---|
797 | |
---|
798 | // return _augment; |
---|
799 | // } |
---|
800 | void run() { |
---|
801 | //int num_of_augmentations=0; |
---|
802 | while (augmentOnShortestPath()) { |
---|
803 | //while (augmentOnBlockingFlow<MutableGraph>()) { |
---|
804 | //std::cout << ++num_of_augmentations << " "; |
---|
805 | //std::cout<<std::endl; |
---|
806 | } |
---|
807 | } |
---|
808 | template<typename MutableGraph> void run() { |
---|
809 | //int num_of_augmentations=0; |
---|
810 | //while (augmentOnShortestPath()) { |
---|
811 | while (augmentOnBlockingFlow<MutableGraph>()) { |
---|
812 | //std::cout << ++num_of_augmentations << " "; |
---|
813 | //std::cout<<std::endl; |
---|
814 | } |
---|
815 | } |
---|
816 | Number flowValue() { |
---|
817 | Number a=0; |
---|
818 | OutEdgeIt e; |
---|
819 | for(G->/*getF*/first(e, s); G->valid(e); G->next(e)) { |
---|
820 | a+=flow->get(e); |
---|
821 | } |
---|
822 | return a; |
---|
823 | } |
---|
824 | }; |
---|
825 | |
---|
826 | |
---|
827 | |
---|
828 | |
---|
829 | |
---|
830 | |
---|
831 | // template <typename Graph, typename Number, typename FlowMap, typename CapacityMap> |
---|
832 | // class MaxFlow2 { |
---|
833 | // public: |
---|
834 | // typedef typename Graph::Node Node; |
---|
835 | // typedef typename Graph::Edge Edge; |
---|
836 | // typedef typename Graph::EdgeIt EdgeIt; |
---|
837 | // typedef typename Graph::OutEdgeIt OutEdgeIt; |
---|
838 | // typedef typename Graph::InEdgeIt InEdgeIt; |
---|
839 | // private: |
---|
840 | // const Graph& G; |
---|
841 | // std::list<Node>& S; |
---|
842 | // std::list<Node>& T; |
---|
843 | // FlowMap& flow; |
---|
844 | // const CapacityMap& capacity; |
---|
845 | // typedef ResGraphWrapper<Graph, Number, FlowMap, CapacityMap > AugGraph; |
---|
846 | // typedef typename AugGraph::OutEdgeIt AugOutEdgeIt; |
---|
847 | // typedef typename AugGraph::Edge AugEdge; |
---|
848 | // typename Graph::NodeMap<bool> SMap; |
---|
849 | // typename Graph::NodeMap<bool> TMap; |
---|
850 | // public: |
---|
851 | // MaxFlow2(const Graph& _G, std::list<Node>& _S, std::list<Node>& _T, FlowMap& _flow, const CapacityMap& _capacity) : G(_G), S(_S), T(_T), flow(_flow), capacity(_capacity), SMap(_G), TMap(_G) { |
---|
852 | // for(typename std::list<Node>::const_iterator i=S.begin(); |
---|
853 | // i!=S.end(); ++i) { |
---|
854 | // SMap.set(*i, true); |
---|
855 | // } |
---|
856 | // for (typename std::list<Node>::const_iterator i=T.begin(); |
---|
857 | // i!=T.end(); ++i) { |
---|
858 | // TMap.set(*i, true); |
---|
859 | // } |
---|
860 | // } |
---|
861 | // bool augment() { |
---|
862 | // AugGraph res_graph(G, flow, capacity); |
---|
863 | // bool _augment=false; |
---|
864 | // Node reached_t_node; |
---|
865 | |
---|
866 | // typedef typename AugGraph::NodeMap<bool> ReachedMap; |
---|
867 | // BfsIterator4< AugGraph, AugOutEdgeIt, ReachedMap > res_bfs(res_graph); |
---|
868 | // for(typename std::list<Node>::const_iterator i=S.begin(); |
---|
869 | // i!=S.end(); ++i) { |
---|
870 | // res_bfs.pushAndSetReached(*i); |
---|
871 | // } |
---|
872 | // //res_bfs.pushAndSetReached(s); |
---|
873 | |
---|
874 | // typename AugGraph::NodeMap<AugEdge> pred(res_graph); |
---|
875 | // //filled up with invalid iterators |
---|
876 | |
---|
877 | // typename AugGraph::NodeMap<Number> free(res_graph); |
---|
878 | |
---|
879 | // //searching for augmenting path |
---|
880 | // while ( !res_bfs.finished() ) { |
---|
881 | // AugOutEdgeIt e=/*AugOutEdgeIt*/(res_bfs); |
---|
882 | // if (e.valid() && res_bfs.isBNodeNewlyReached()) { |
---|
883 | // Node v=res_graph.tail(e); |
---|
884 | // Node w=res_graph.head(e); |
---|
885 | // pred.set(w, e); |
---|
886 | // if (pred.get(v).valid()) { |
---|
887 | // free.set(w, std::min(free.get(v), e.free())); |
---|
888 | // } else { |
---|
889 | // free.set(w, e.free()); |
---|
890 | // } |
---|
891 | // if (TMap.get(res_graph.head(e))) { |
---|
892 | // _augment=true; |
---|
893 | // reached_t_node=res_graph.head(e); |
---|
894 | // break; |
---|
895 | // } |
---|
896 | // } |
---|
897 | |
---|
898 | // ++res_bfs; |
---|
899 | // } //end of searching augmenting path |
---|
900 | |
---|
901 | // if (_augment) { |
---|
902 | // Node n=reached_t_node; |
---|
903 | // Number augment_value=free.get(reached_t_node); |
---|
904 | // while (pred.get(n).valid()) { |
---|
905 | // AugEdge e=pred.get(n); |
---|
906 | // e.augment(augment_value); |
---|
907 | // n=res_graph.tail(e); |
---|
908 | // } |
---|
909 | // } |
---|
910 | |
---|
911 | // return _augment; |
---|
912 | // } |
---|
913 | // void run() { |
---|
914 | // while (augment()) { } |
---|
915 | // } |
---|
916 | // Number flowValue() { |
---|
917 | // Number a=0; |
---|
918 | // for(typename std::list<Node>::const_iterator i=S.begin(); |
---|
919 | // i!=S.end(); ++i) { |
---|
920 | // for(OutEdgeIt e=G.template first<OutEdgeIt>(*i); e.valid(); ++e) { |
---|
921 | // a+=flow.get(e); |
---|
922 | // } |
---|
923 | // for(InEdgeIt e=G.template first<InEdgeIt>(*i); e.valid(); ++e) { |
---|
924 | // a-=flow.get(e); |
---|
925 | // } |
---|
926 | // } |
---|
927 | // return a; |
---|
928 | // } |
---|
929 | // }; |
---|
930 | |
---|
931 | |
---|
932 | |
---|
933 | } // namespace hugo |
---|
934 | |
---|
935 | #endif //EDMONDS_KARP_H |
---|