1 | // -*- mode:C++ -*- |
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2 | |
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3 | #include <lemon/smart_graph.h> |
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4 | #include <lemon/maps.h> |
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5 | #include <vector> |
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6 | #include <iostream> |
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7 | |
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8 | using namespace lemon; |
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9 | |
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10 | struct _BFS_DEFAULT_VIS {}; |
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11 | struct _BFS_CUSTOM_VIS {}; |
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12 | |
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13 | |
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14 | class _Bfs_Traits |
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15 | { |
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16 | typedef ListGraph Graph; |
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17 | } |
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18 | |
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19 | template<class T> |
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20 | class _Bfs |
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21 | { |
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22 | public: |
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23 | typedef typename T::Graph Graph; |
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24 | typedef typename T::Reached Reached; |
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25 | typedef typename T::PredNode PredNode; |
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26 | typedef typename T::PredEdge PredEdge; |
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27 | typedef typename T::Priority Priority; |
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28 | |
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29 | typedef typename T::DefaultReachedTag DefaultReachedTag; |
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30 | |
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31 | typedef typename Graph::Node Node; |
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32 | typedef typename Graph::OutEdgeIt OutEdgeIt; |
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33 | |
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34 | const Graph &_graph; |
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35 | |
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36 | Node _source; |
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37 | |
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38 | Reached *_visited; |
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39 | PredNode _predNode; |
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40 | PredEdge _predEdge; |
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41 | Priority _priority; |
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42 | |
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43 | _Bfs(const Graph &g, |
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44 | Node s, |
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45 | Reached *v, |
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46 | PredNode &pn, |
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47 | PredEdge &pe, |
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48 | Priority &pr) :_graph(g), _source(s), |
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49 | _visited(v), |
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50 | _predNode(pn), _predEdge(pe), _priority(pr) { } |
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51 | |
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52 | |
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53 | int run(const _Bfs_CUSTOM_VIS &) |
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54 | { |
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55 | using namespace std; |
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56 | |
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57 | int N=_graph.nodeNum(); |
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58 | vector<Node> Q(N); |
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59 | int Qh=0; |
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60 | int Qt=0; |
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61 | |
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62 | for(typename Graph::NodeIt n(_graph);n!=INVALID;++n) |
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63 | _visited->set(n,false); |
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64 | |
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65 | Q[Qh++]=_source; |
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66 | _visited->set(_source,true); |
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67 | do { |
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68 | Node m; |
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69 | Node n=Q[Qt++]; |
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70 | for(OutEdgeIt e(_graph,n);e!=INVALID;++e) |
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71 | if(!(*_visited)[m=_graph.target(e)]) { |
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72 | Q[Qh++]=m; |
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73 | _visited->set(m,true); |
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74 | _predNode.set(m,n); |
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75 | _predEdge.set(m,e); |
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76 | } |
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77 | } while(Qt!=Qh); |
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78 | |
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79 | return 1; //Why return 1? |
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80 | } |
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81 | int run(const _BFS_DEFAULT_VIS &) |
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82 | { |
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83 | _visited= new Reached(_graph); |
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84 | int r = run(_BFS_CUSTOM_VIS()); |
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85 | delete _visited; |
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86 | return r; |
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87 | } |
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88 | int run() { return run(DefaultReachedTag());} |
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89 | |
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90 | template<class T> _Bfs<Graph,T,_BFS_CUSTOM_VIS,PredNode,PredEdge,Priority> |
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91 | setVisitMap(T &t) |
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92 | { |
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93 | return _Bfs<Graph,T,_BFS_CUSTOM_VIS,PredNode,PredEdge,Priority> |
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94 | (_graph,_source,&t,_predNode,_predEdge,_priority); |
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95 | } |
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96 | |
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97 | template<class T> |
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98 | _Bfs<Graph,Reached,DefaultReachedTag,T,PredEdge,Priority> |
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99 | setPredNodeMap(T &t) |
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100 | { |
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101 | return _BFS<Graph,Reached,DefaultReachedTag,T,PredEdge,Priority> |
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102 | (_graph,_source, |
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103 | _visited, |
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104 | t,_predEdge,_priority); |
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105 | } |
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106 | |
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107 | template<class T> |
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108 | _BFS<Graph,Reached,DefaultReachedTag,PredNode,T,Priority> |
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109 | setPredEdgeMap(T &t) |
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110 | { |
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111 | return _BFS<Graph,Reached,DefaultReachedTag,PredNode,T,Priority> |
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112 | (_graph,_source, |
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113 | _visited, |
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114 | _predNode,t,_priority); |
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115 | } |
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116 | |
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117 | _Bfs<Graph,Reached,DefaultReachedTag,PredNode,PredEdge,Priority> |
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118 | setNothing() |
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119 | { |
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120 | return _Bfs<Graph,Reached,DefaultReachedTag,PredNode,PredEdge,Priority> |
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121 | (_graph,_source, |
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122 | _visited, |
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123 | _predNode,_predEdge,_priority); |
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124 | } |
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125 | }; |
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126 | |
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127 | |
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128 | template<class G> |
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129 | _Bfs<G, |
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130 | typename G::template NodeMap<bool>, |
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131 | _BFS_DEFAULT_VIS, |
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132 | NullMap<typename G::Node,typename G::Node>, |
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133 | NullMap<typename G::Node,typename G::Edge>, |
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134 | NullMap<typename G::Node,int> > |
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135 | bfs(const G &g,typename G::Node s) |
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136 | { |
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137 | // typename G::template NodeMap<bool> v(g); |
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138 | |
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139 | return _Bfs < G, |
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140 | typename G::template NodeMap<bool>, |
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141 | _BFS_DEFAULT_VIS, |
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142 | NullMap<typename G::Node,typename G::Node>, |
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143 | NullMap<typename G::Node,typename G::Edge>, |
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144 | NullMap<typename G::Node,int> > |
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145 | (g,s, |
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146 | (typename G::template NodeMap<bool>*)(NULL), |
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147 | *((NullMap<typename G::Node,typename G::Node>*)(NULL)), |
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148 | *((NullMap<typename G::Node,typename G::Edge> *)(NULL)), |
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149 | *((NullMap<typename G::Node,int> *)(NULL)) |
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150 | ); |
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151 | } |
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152 | |
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153 | |
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154 | class MyReachedMap : public SmartGraph::NodeMap<bool> |
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155 | { |
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156 | const SmartGraph &_G; |
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157 | public: |
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158 | MyReachedMap(const SmartGraph &G) : SmartGraph::NodeMap<bool>(G), _G(G) {} |
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159 | void set(SmartGraph::Node n,bool b) |
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160 | { |
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161 | SmartGraph::NodeMap<bool>::set(n,b); |
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162 | if(b) std::cout << _G.id(n) << std::endl; |
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163 | } |
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164 | }; |
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165 | |
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166 | |
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167 | int main() |
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168 | { |
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169 | SmartGraph G; |
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170 | SmartGraph::Node s=G.addNode(); |
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171 | SmartGraph::Node n1=G.addNode(); |
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172 | SmartGraph::Node n2=G.addNode(); |
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173 | SmartGraph::Node n3=G.addNode(); |
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174 | SmartGraph::Node n4=G.addNode(); |
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175 | SmartGraph::Node n5=G.addNode(); |
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176 | SmartGraph::Node n6=G.addNode(); |
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177 | SmartGraph::Node n7=G.addNode(); |
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178 | |
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179 | G.addEdge(s,n1);G.addEdge(s,n3);G.addEdge(n1,n2);G.addEdge(n1,n3); |
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180 | G.addEdge(s,n4);G.addEdge(n4,n7);G.addEdge(n7,n6);G.addEdge(n4,n5); |
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181 | G.addEdge(n7,n2);G.addEdge(n6,n3);G.addEdge(n4,s);G.addEdge(n1,s); |
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182 | |
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183 | |
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184 | |
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185 | SmartGraph::NodeMap<SmartGraph::Node> m(G); |
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186 | SmartGraph::NodeMap<SmartGraph::Edge> em(G); |
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187 | |
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188 | MyReachedMap vm(G); |
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189 | |
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190 | |
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191 | //Runs BFS on graph 'G' from node 's'. |
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192 | //(It practically does nothing, for it throws away its result.) |
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193 | bfs(G,s).run(); |
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194 | |
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195 | //Runs BFS on graph 'G' from node 's'. Puts the predessor nodes to 'm'. |
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196 | bfs(G,s).setPredNodeMap(m).run(); |
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197 | |
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198 | //Runs BFS on graph 'G' from node 's'. |
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199 | //Puts the predessor nodes to 'm' and the edges of the bfs tree to 'em'. |
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200 | bfs(G,s).setPredNodeMap(m).setPredEdgeMap(em).run(); |
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201 | |
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202 | //Runs BFS on graph 'G' from node 's'. |
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203 | //It uses a scpecial 'visited map' that prints out the reached nodes. |
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204 | bfs(G,s).setVisitMap(vm).run(); |
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205 | |
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206 | } |
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