1 | // -*- mode:C++ -*- |
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2 | |
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3 | #ifndef HUGO_LIST_GRAPH_H |
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4 | #define HUGO_LIST_GRAPH_H |
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5 | |
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6 | ///\ingroup graphs |
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7 | ///\file |
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8 | ///\brief ListGraph, SymListGraph, NodeSet and EdgeSet classes. |
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9 | |
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10 | #include <vector> |
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11 | #include <climits> |
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12 | |
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13 | #include "invalid.h" |
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14 | |
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15 | #include "array_map_factory.h" |
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16 | #include "map_registry.h" |
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17 | |
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18 | #include "map_defines.h" |
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19 | |
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20 | namespace hugo { |
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21 | |
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22 | /// \addtogroup graphs |
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23 | /// @{ |
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24 | |
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25 | ///A list graph class. |
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26 | |
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27 | ///This is a simple and fast erasable graph implementation. |
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28 | /// |
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29 | ///It conforms to the graph interface documented under |
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30 | ///the description of \ref GraphSkeleton. |
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31 | ///\sa \ref GraphSkeleton. |
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32 | class ListGraph { |
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33 | |
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34 | //Nodes are double linked. |
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35 | //The free nodes are only single linked using the "next" field. |
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36 | struct NodeT |
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37 | { |
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38 | int first_in,first_out; |
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39 | int prev, next; |
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40 | // NodeT() {} |
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41 | }; |
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42 | //Edges are double linked. |
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43 | //The free edges are only single linked using the "next_in" field. |
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44 | struct EdgeT |
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45 | { |
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46 | int head, tail; |
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47 | int prev_in, prev_out; |
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48 | int next_in, next_out; |
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49 | //FIXME: is this necessary? |
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50 | // EdgeT() : next_in(-1), next_out(-1) prev_in(-1), prev_out(-1) {} |
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51 | }; |
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52 | |
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53 | std::vector<NodeT> nodes; |
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54 | //The first node |
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55 | int first_node; |
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56 | //The first free node |
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57 | int first_free_node; |
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58 | std::vector<EdgeT> edges; |
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59 | //The first free edge |
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60 | int first_free_edge; |
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61 | |
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62 | protected: |
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63 | |
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64 | public: |
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65 | |
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66 | class Node; |
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67 | class Edge; |
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68 | |
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69 | typedef ListGraph Graph; |
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70 | |
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71 | public: |
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72 | |
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73 | class NodeIt; |
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74 | class EdgeIt; |
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75 | class OutEdgeIt; |
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76 | class InEdgeIt; |
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77 | |
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78 | CREATE_MAP_REGISTRIES; |
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79 | CREATE_MAPS(ArrayMapFactory); |
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80 | public: |
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81 | |
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82 | ListGraph() : nodes(), first_node(-1), |
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83 | first_free_node(-1), edges(), first_free_edge(-1) {} |
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84 | ListGraph(const ListGraph &_g) : nodes(_g.nodes), first_node(_g.first_node), |
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85 | first_free_node(_g.first_free_node), |
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86 | edges(_g.edges), |
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87 | first_free_edge(_g.first_free_edge) {} |
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88 | |
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89 | |
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90 | int nodeNum() const { return nodes.size(); } //FIXME: What is this? |
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91 | int edgeNum() const { return edges.size(); } //FIXME: What is this? |
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92 | |
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93 | ///Set the expected number of edges |
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94 | |
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95 | ///With this function, it is possible to set the expected number of edges. |
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96 | ///The use of this fasten the building of the graph and makes |
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97 | ///it possible to avoid the superfluous memory allocation. |
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98 | void reserveEdge(int n) { edges.reserve(n); }; |
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99 | |
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100 | ///\bug This function does something different than |
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101 | ///its name would suggests... |
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102 | int maxNodeId() const { return nodes.size(); } //FIXME: What is this? |
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103 | ///\bug This function does something different than |
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104 | ///its name would suggests... |
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105 | int maxEdgeId() const { return edges.size(); } //FIXME: What is this? |
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106 | |
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107 | Node tail(Edge e) const { return edges[e.n].tail; } |
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108 | Node head(Edge e) const { return edges[e.n].head; } |
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109 | |
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110 | Node aNode(OutEdgeIt e) const { return edges[e.n].tail; } |
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111 | Node aNode(InEdgeIt e) const { return edges[e.n].head; } |
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112 | |
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113 | Node bNode(OutEdgeIt e) const { return edges[e.n].head; } |
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114 | Node bNode(InEdgeIt e) const { return edges[e.n].tail; } |
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115 | |
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116 | NodeIt& first(NodeIt& v) const { |
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117 | v=NodeIt(*this); return v; } |
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118 | EdgeIt& first(EdgeIt& e) const { |
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119 | e=EdgeIt(*this); return e; } |
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120 | OutEdgeIt& first(OutEdgeIt& e, const Node v) const { |
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121 | e=OutEdgeIt(*this,v); return e; } |
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122 | InEdgeIt& first(InEdgeIt& e, const Node v) const { |
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123 | e=InEdgeIt(*this,v); return e; } |
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124 | |
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125 | // template< typename It > |
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126 | // It first() const { It e; first(e); return e; } |
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127 | |
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128 | // template< typename It > |
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129 | // It first(Node v) const { It e; first(e,v); return e; } |
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130 | |
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131 | bool valid(Edge e) const { return e.n!=-1; } |
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132 | bool valid(Node n) const { return n.n!=-1; } |
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133 | |
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134 | void setInvalid(Edge &e) { e.n=-1; } |
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135 | void setInvalid(Node &n) { n.n=-1; } |
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136 | |
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137 | template <typename It> It getNext(It it) const |
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138 | { It tmp(it); return next(tmp); } |
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139 | |
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140 | NodeIt& next(NodeIt& it) const { |
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141 | it.n=nodes[it.n].next; |
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142 | return it; |
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143 | } |
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144 | OutEdgeIt& next(OutEdgeIt& it) const |
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145 | { it.n=edges[it.n].next_out; return it; } |
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146 | InEdgeIt& next(InEdgeIt& it) const |
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147 | { it.n=edges[it.n].next_in; return it; } |
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148 | EdgeIt& next(EdgeIt& it) const { |
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149 | if(edges[it.n].next_in!=-1) { |
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150 | it.n=edges[it.n].next_in; |
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151 | } |
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152 | else { |
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153 | int n; |
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154 | for(n=nodes[edges[it.n].head].next; |
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155 | n!=-1 && nodes[n].first_in == -1; |
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156 | n = nodes[n].next) ; |
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157 | it.n = (n==-1)?-1:nodes[n].first_in; |
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158 | } |
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159 | return it; |
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160 | } |
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161 | |
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162 | int id(Node v) const { return v.n; } |
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163 | int id(Edge e) const { return e.n; } |
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164 | |
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165 | /// Adds a new node to the graph. |
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166 | |
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167 | /// \todo It adds the nodes in a reversed order. |
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168 | /// (i.e. the lastly added node becomes the first.) |
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169 | Node addNode() { |
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170 | int n; |
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171 | |
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172 | if(first_free_node==-1) |
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173 | { |
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174 | n = nodes.size(); |
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175 | nodes.push_back(NodeT()); |
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176 | } |
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177 | else { |
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178 | n = first_free_node; |
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179 | first_free_node = nodes[n].next; |
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180 | } |
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181 | |
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182 | nodes[n].next = first_node; |
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183 | if(first_node != -1) nodes[first_node].prev = n; |
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184 | first_node = n; |
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185 | nodes[n].prev = -1; |
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186 | |
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187 | nodes[n].first_in = nodes[n].first_out = -1; |
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188 | |
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189 | Node nn; nn.n=n; |
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190 | |
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191 | //Update dynamic maps |
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192 | node_maps.add(nn); |
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193 | |
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194 | return nn; |
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195 | } |
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196 | |
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197 | Edge addEdge(Node u, Node v) { |
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198 | int n; |
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199 | |
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200 | if(first_free_edge==-1) |
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201 | { |
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202 | n = edges.size(); |
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203 | edges.push_back(EdgeT()); |
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204 | } |
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205 | else { |
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206 | n = first_free_edge; |
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207 | first_free_edge = edges[n].next_in; |
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208 | } |
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209 | |
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210 | edges[n].tail = u.n; edges[n].head = v.n; |
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211 | |
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212 | edges[n].next_out = nodes[u.n].first_out; |
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213 | if(nodes[u.n].first_out != -1) edges[nodes[u.n].first_out].prev_out = n; |
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214 | edges[n].next_in = nodes[v.n].first_in; |
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215 | if(nodes[v.n].first_in != -1) edges[nodes[v.n].first_in].prev_in = n; |
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216 | edges[n].prev_in = edges[n].prev_out = -1; |
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217 | |
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218 | nodes[u.n].first_out = nodes[v.n].first_in = n; |
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219 | |
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220 | Edge e; e.n=n; |
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221 | |
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222 | //Update dynamic maps |
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223 | edge_maps.add(e); |
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224 | |
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225 | return e; |
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226 | } |
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227 | |
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228 | private: |
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229 | void eraseEdge(int n) { |
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230 | |
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231 | if(edges[n].next_in!=-1) |
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232 | edges[edges[n].next_in].prev_in = edges[n].prev_in; |
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233 | if(edges[n].prev_in!=-1) |
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234 | edges[edges[n].prev_in].next_in = edges[n].next_in; |
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235 | else nodes[edges[n].head].first_in = edges[n].next_in; |
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236 | |
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237 | if(edges[n].next_out!=-1) |
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238 | edges[edges[n].next_out].prev_out = edges[n].prev_out; |
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239 | if(edges[n].prev_out!=-1) |
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240 | edges[edges[n].prev_out].next_out = edges[n].next_out; |
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241 | else nodes[edges[n].tail].first_out = edges[n].next_out; |
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242 | |
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243 | edges[n].next_in = first_free_edge; |
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244 | first_free_edge = n; |
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245 | |
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246 | //Update dynamic maps |
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247 | Edge e; e.n=n; |
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248 | } |
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249 | |
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250 | public: |
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251 | |
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252 | void erase(Node nn) { |
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253 | int n=nn.n; |
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254 | |
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255 | int m; |
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256 | while((m=nodes[n].first_in)!=-1) eraseEdge(m); |
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257 | while((m=nodes[n].first_out)!=-1) eraseEdge(m); |
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258 | |
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259 | if(nodes[n].next != -1) nodes[nodes[n].next].prev = nodes[n].prev; |
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260 | if(nodes[n].prev != -1) nodes[nodes[n].prev].next = nodes[n].next; |
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261 | else first_node = nodes[n].next; |
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262 | |
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263 | nodes[n].next = first_free_node; |
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264 | first_free_node = n; |
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265 | |
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266 | //Update dynamic maps |
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267 | node_maps.erase(nn); |
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268 | } |
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269 | |
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270 | void erase(Edge e) { |
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271 | edge_maps.erase(e); |
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272 | eraseEdge(e.n); |
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273 | } |
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274 | |
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275 | ///\bug Dynamic maps must be updated! |
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276 | /// |
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277 | void clear() { |
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278 | nodes.clear();edges.clear(); |
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279 | first_node=first_free_node=first_free_edge=-1; |
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280 | } |
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281 | |
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282 | class Node { |
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283 | friend class ListGraph; |
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284 | template <typename T> friend class NodeMap; |
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285 | |
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286 | friend class Edge; |
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287 | friend class OutEdgeIt; |
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288 | friend class InEdgeIt; |
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289 | friend class SymEdge; |
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290 | |
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291 | protected: |
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292 | int n; |
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293 | friend int ListGraph::id(Node v) const; |
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294 | Node(int nn) {n=nn;} |
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295 | public: |
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296 | Node() {} |
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297 | Node (Invalid) { n=-1; } |
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298 | bool operator==(const Node i) const {return n==i.n;} |
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299 | bool operator!=(const Node i) const {return n!=i.n;} |
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300 | bool operator<(const Node i) const {return n<i.n;} |
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301 | }; |
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302 | |
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303 | class NodeIt : public Node { |
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304 | friend class ListGraph; |
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305 | public: |
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306 | NodeIt() : Node() { } |
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307 | NodeIt(Invalid i) : Node(i) { } |
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308 | NodeIt(const ListGraph& G) : Node(G.first_node) { } |
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309 | ///\todo Undocumented conversion Node -\> NodeIt. |
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310 | NodeIt(const ListGraph& G, const Node &n) : Node(n) { } |
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311 | }; |
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312 | |
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313 | class Edge { |
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314 | friend class ListGraph; |
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315 | template <typename T> friend class EdgeMap; |
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316 | |
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317 | //template <typename T> friend class SymListGraph::SymEdgeMap; |
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318 | //friend Edge SymListGraph::opposite(Edge) const; |
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319 | |
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320 | friend class Node; |
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321 | friend class NodeIt; |
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322 | protected: |
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323 | int n; |
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324 | friend int ListGraph::id(Edge e) const; |
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325 | |
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326 | Edge(int nn) {n=nn;} |
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327 | public: |
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328 | Edge() { } |
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329 | Edge (Invalid) { n=-1; } |
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330 | bool operator==(const Edge i) const {return n==i.n;} |
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331 | bool operator!=(const Edge i) const {return n!=i.n;} |
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332 | bool operator<(const Edge i) const {return n<i.n;} |
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333 | ///\bug This is a workaround until somebody tells me how to |
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334 | ///make class \c SymListGraph::SymEdgeMap friend of Edge |
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335 | int &idref() {return n;} |
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336 | const int &idref() const {return n;} |
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337 | }; |
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338 | |
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339 | class EdgeIt : public Edge { |
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340 | friend class ListGraph; |
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341 | public: |
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342 | EdgeIt(const ListGraph& G) : Edge() { |
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343 | int m; |
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344 | for(m=G.first_node; |
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345 | m!=-1 && G.nodes[m].first_in == -1; m = G.nodes[m].next); |
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346 | n = (m==-1)?-1:G.nodes[m].first_in; |
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347 | } |
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348 | EdgeIt (Invalid i) : Edge(i) { } |
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349 | EdgeIt() : Edge() { } |
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350 | ///\bug This is a workaround until somebody tells me how to |
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351 | ///make class \c SymListGraph::SymEdgeMap friend of Edge |
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352 | int &idref() {return n;} |
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353 | }; |
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354 | |
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355 | class OutEdgeIt : public Edge { |
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356 | friend class ListGraph; |
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357 | public: |
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358 | OutEdgeIt() : Edge() { } |
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359 | OutEdgeIt (Invalid i) : Edge(i) { } |
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360 | |
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361 | OutEdgeIt(const ListGraph& G,const Node v) |
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362 | : Edge(G.nodes[v.n].first_out) {} |
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363 | }; |
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364 | |
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365 | class InEdgeIt : public Edge { |
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366 | friend class ListGraph; |
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367 | public: |
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368 | InEdgeIt() : Edge() { } |
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369 | InEdgeIt (Invalid i) : Edge(i) { } |
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370 | InEdgeIt(const ListGraph& G,Node v) :Edge(G.nodes[v.n].first_in) {} |
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371 | }; |
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372 | |
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373 | }; |
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374 | |
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375 | ///Graph for bidirectional edges. |
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376 | |
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377 | ///The purpose of this graph structure is to handle graphs |
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378 | ///having bidirectional edges. Here the function \c addEdge(u,v) adds a pair |
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379 | ///of oppositely directed edges. |
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380 | ///There is a new edge map type called |
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381 | ///\ref SymListGraph::SymEdgeMap "SymEdgeMap" |
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382 | ///that complements this |
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383 | ///feature by |
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384 | ///storing shared values for the edge pairs. The usual |
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385 | ///\ref GraphSkeleton::EdgeMap "EdgeMap" |
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386 | ///can be used |
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387 | ///as well. |
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388 | /// |
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389 | ///The oppositely directed edge can also be obtained easily |
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390 | ///using \ref opposite. |
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391 | /// |
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392 | ///Here erase(Edge) deletes a pair of edges. |
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393 | /// |
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394 | ///\todo this date structure need some reconsiderations. Maybe it |
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395 | ///should be implemented independently from ListGraph. |
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396 | |
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397 | } |
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398 | |
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399 | #endif //HUGO_LIST_GRAPH_H |
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