1 /* -*- C++ -*- |
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2 * |
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3 * lemon/undir_graph_extender.h - Part of LEMON, a generic C++ |
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4 * optimization library |
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5 * |
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6 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi |
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7 * Kutatocsoport (Egervary Research Group on Combinatorial Optimization, |
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8 * EGRES). |
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9 * |
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10 * Permission to use, modify and distribute this software is granted |
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11 * provided that this copyright notice appears in all copies. For |
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12 * precise terms see the accompanying LICENSE file. |
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13 * |
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14 * This software is provided "AS IS" with no warranty of any kind, |
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15 * express or implied, and with no claim as to its suitability for any |
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16 * purpose. |
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17 * |
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18 */ |
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19 |
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20 #ifndef LEMON_UNDIR_GRAPH_EXTENDER_H |
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21 #define LEMON_UNDIR_GRAPH_EXTENDER_H |
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22 |
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23 #include <lemon/invalid.h> |
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24 |
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25 namespace lemon { |
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26 |
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27 template <typename _Base> |
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28 class UndirGraphExtender : public _Base { |
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29 typedef _Base Parent; |
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30 typedef UndirGraphExtender Graph; |
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31 |
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32 public: |
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33 |
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34 typedef typename Parent::Edge UndirEdge; |
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35 typedef typename Parent::Node Node; |
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36 |
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37 class Edge : public UndirEdge { |
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38 friend class UndirGraphExtender; |
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39 |
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40 protected: |
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41 // FIXME: Marci use opposite logic in his graph adaptors. It would |
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42 // be reasonable to syncronize... |
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43 bool forward; |
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44 |
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45 Edge(const UndirEdge &ue, bool _forward) : |
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46 UndirEdge(ue), forward(_forward) {} |
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47 |
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48 public: |
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49 Edge() {} |
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50 |
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51 /// Invalid edge constructor |
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52 Edge(Invalid i) : UndirEdge(i), forward(true) {} |
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53 |
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54 bool operator==(const Edge &that) const { |
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55 return forward==that.forward && UndirEdge(*this)==UndirEdge(that); |
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56 } |
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57 bool operator!=(const Edge &that) const { |
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58 return forward!=that.forward || UndirEdge(*this)!=UndirEdge(that); |
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59 } |
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60 bool operator<(const Edge &that) const { |
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61 return forward<that.forward || |
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62 (!(that.forward<forward) && UndirEdge(*this)<UndirEdge(that)); |
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63 } |
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64 }; |
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65 |
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66 |
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67 /// \brief Edge of opposite direction. |
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68 /// |
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69 /// Returns the Edge of opposite direction. |
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70 Edge oppositeEdge(const Edge &e) const { |
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71 return Edge(e,!e.forward); |
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72 } |
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73 |
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74 public: |
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75 /// \todo Shouldn't the "source" of an undirected edge be called "aNode" |
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76 /// or something??? |
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77 using Parent::source; |
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78 |
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79 /// Source of the given Edge. |
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80 Node source(const Edge &e) const { |
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81 return e.forward ? Parent::source(e) : Parent::target(e); |
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82 } |
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83 |
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84 /// \todo Shouldn't the "target" of an undirected edge be called "bNode" |
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85 /// or something??? |
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86 using Parent::target; |
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87 |
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88 /// Target of the given Edge. |
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89 Node target(const Edge &e) const { |
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90 return e.forward ? Parent::target(e) : Parent::source(e); |
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91 } |
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92 |
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93 Node oppositeNode(const Node &n, const UndirEdge &e) const { |
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94 if( n == Parent::source(e)) |
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95 return Parent::target(e); |
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96 else if( n == Parent::target(e)) |
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97 return Parent::source(e); |
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98 else |
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99 return INVALID; |
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100 } |
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101 |
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102 /// \brief Directed edge from an undirected edge and a source node. |
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103 /// |
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104 /// Returns a (directed) Edge corresponding to the specified UndirEdge |
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105 /// and source Node. |
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106 /// |
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107 Edge direct(const UndirEdge &ue, const Node &s) const { |
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108 return Edge(ue, s == source(ue)); |
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109 } |
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110 |
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111 /// \brief Directed edge from an undirected edge. |
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112 /// |
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113 /// Returns a directed edge corresponding to the specified UndirEdge. |
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114 /// If the given bool is true the given undirected edge and the |
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115 /// returned edge have the same source node. |
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116 Edge direct(const UndirEdge &ue, bool d) const { |
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117 return Edge(ue, d); |
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118 } |
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119 |
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120 /// Returns whether the given directed edge is same orientation as the |
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121 /// corresponding undirected edge. |
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122 /// |
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123 /// \todo reference to the corresponding point of the undirected graph |
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124 /// concept. "What does the direction of an undirected edge mean?" |
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125 bool direction(const Edge &e) const { return e.forward; } |
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126 |
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127 |
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128 using Parent::first; |
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129 void first(Edge &e) const { |
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130 Parent::first(e); |
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131 e.forward=true; |
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132 } |
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133 |
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134 using Parent::next; |
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135 void next(Edge &e) const { |
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136 if( e.forward ) { |
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137 e.forward = false; |
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138 } |
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139 else { |
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140 Parent::next(e); |
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141 e.forward = true; |
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142 } |
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143 } |
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144 |
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145 public: |
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146 |
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147 void firstOut(Edge &e, const Node &n) const { |
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148 Parent::firstIn(e,n); |
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149 if( UndirEdge(e) != INVALID ) { |
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150 e.forward = false; |
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151 } |
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152 else { |
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153 Parent::firstOut(e,n); |
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154 e.forward = true; |
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155 } |
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156 } |
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157 void nextOut(Edge &e) const { |
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158 if( ! e.forward ) { |
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159 Node n = Parent::target(e); |
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160 Parent::nextIn(e); |
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161 if( UndirEdge(e) == INVALID ) { |
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162 Parent::firstOut(e, n); |
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163 e.forward = true; |
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164 } |
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165 } |
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166 else { |
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167 Parent::nextOut(e); |
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168 } |
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169 } |
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170 |
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171 void firstIn(Edge &e, const Node &n) const { |
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172 Parent::firstOut(e,n); |
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173 if( UndirEdge(e) != INVALID ) { |
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174 e.forward = false; |
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175 } |
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176 else { |
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177 Parent::firstIn(e,n); |
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178 e.forward = true; |
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179 } |
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180 } |
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181 void nextIn(Edge &e) const { |
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182 if( ! e.forward ) { |
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183 Node n = Parent::source(e); |
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184 Parent::nextOut(e); |
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185 if( UndirEdge(e) == INVALID ) { |
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186 Parent::firstIn(e, n); |
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187 e.forward = true; |
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188 } |
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189 } |
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190 else { |
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191 Parent::nextIn(e); |
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192 } |
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193 } |
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194 |
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195 void firstInc(UndirEdge &e, const Node &n) const { |
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196 Parent::firstOut(e, n); |
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197 if (e != INVALID) return; |
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198 Parent::firstIn(e, n); |
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199 } |
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200 void nextInc(UndirEdge &e, const Node &n) const { |
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201 if (Parent::source(e) == n) { |
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202 Parent::nextOut(e); |
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203 if (e != INVALID) return; |
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204 Parent::firstIn(e, n); |
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205 } else { |
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206 Parent::nextIn(e); |
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207 } |
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208 } |
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209 |
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210 void firstInc(UndirEdge &e, bool &d, const Node &n) const { |
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211 d = true; |
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212 Parent::firstOut(e, n); |
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213 if (e != INVALID) return; |
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214 d = false; |
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215 Parent::firstIn(e, n); |
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216 } |
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217 void nextInc(UndirEdge &e, bool &d) const { |
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218 if (d) { |
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219 Node s = Parent::source(e); |
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220 Parent::nextOut(e); |
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221 if (e != INVALID) return; |
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222 d = false; |
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223 Parent::firstIn(e, s); |
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224 } else { |
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225 Parent::nextIn(e); |
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226 } |
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227 } |
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228 |
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229 // Miscellaneous stuff: |
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230 |
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231 /// \todo these methods (id, maxEdgeId) should be moved into separate |
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232 /// Extender |
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233 |
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234 // using Parent::id; |
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235 // Using "using" is not a good idea, cause it could be that there is |
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236 // no "id" in Parent... |
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237 |
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238 int id(const Node &n) const { |
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239 return Parent::id(n); |
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240 } |
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241 |
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242 int id(const UndirEdge &e) const { |
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243 return Parent::id(e); |
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244 } |
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245 |
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246 int id(const Edge &e) const { |
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247 return 2 * Parent::id(e) + int(e.forward); |
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248 } |
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249 |
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250 |
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251 int maxId(Node) const { |
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252 return Parent::maxId(Node()); |
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253 } |
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254 |
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255 int maxId(Edge) const { |
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256 return 2 * Parent::maxId(typename Parent::Edge()) + 1; |
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257 } |
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258 int maxId(UndirEdge) const { |
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259 return Parent::maxId(typename Parent::Edge()); |
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260 } |
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261 |
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262 |
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263 int edgeNum() const { |
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264 return 2 * Parent::edgeNum(); |
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265 } |
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266 |
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267 int undirEdgeNum() const { |
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268 return Parent::edgeNum(); |
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269 } |
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270 |
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271 Edge findEdge(Node source, Node target, Edge prev) const { |
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272 if (prev == INVALID) { |
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273 UndirEdge edge = Parent::findEdge(source, target); |
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274 if (edge != INVALID) return direct(edge, true); |
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275 edge = Parent::findEdge(target, source); |
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276 if (edge != INVALID) return direct(edge, false); |
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277 } else if (direction(prev)) { |
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278 UndirEdge edge = Parent::findEdge(source, target, prev); |
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279 if (edge != INVALID) return direct(edge, true); |
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280 edge = Parent::findEdge(target, source); |
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281 if (edge != INVALID) return direct(edge, false); |
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282 } else { |
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283 UndirEdge edge = Parent::findEdge(target, source, prev); |
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284 if (edge != INVALID) return direct(edge, false); |
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285 } |
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286 return INVALID; |
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287 } |
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288 |
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289 UndirEdge findUndirEdge(Node source, Node target, UndirEdge prev) const { |
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290 if (prev == INVALID) { |
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291 UndirEdge edge = Parent::findEdge(source, target); |
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292 if (edge != INVALID) return edge; |
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293 edge = Parent::findEdge(target, source); |
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294 if (edge != INVALID) return edge; |
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295 } else if (Parent::source(prev) == source) { |
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296 UndirEdge edge = Parent::findEdge(source, target, prev); |
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297 if (edge != INVALID) return edge; |
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298 edge = Parent::findEdge(target, source); |
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299 if (edge != INVALID) return edge; |
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300 } else { |
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301 UndirEdge edge = Parent::findEdge(target, source, prev); |
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302 if (edge != INVALID) return edge; |
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303 } |
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304 return INVALID; |
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305 } |
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306 |
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307 }; |
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308 |
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309 } |
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310 |
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311 #endif // LEMON_UNDIR_GRAPH_EXTENDER_H |
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