1 | /* -*- C++ -*- |
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2 | * |
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3 | * src/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) 2004 Egervary Jeno Kombinatorikus Optimalizalasi |
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7 | * Kutatocsoport (Egervary Combinatorial Optimization Research Group, |
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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 wrappers. 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 | public: |
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46 | Edge() {} |
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47 | /// Construct a direct edge from undirect edge and a direction. |
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48 | Edge(const UndirEdge &ue, bool _forward) : |
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49 | UndirEdge(ue), forward(_forward) {} |
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50 | /// Invalid edge constructor |
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51 | Edge(Invalid i) : UndirEdge(i), forward(false) {} |
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52 | |
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53 | bool operator==(const Edge &that) const { |
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54 | return forward==that.forward && UndirEdge(*this)==UndirEdge(that); |
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55 | } |
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56 | bool operator!=(const Edge &that) const { |
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57 | return forward!=that.forward || UndirEdge(*this)!=UndirEdge(that); |
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58 | } |
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59 | bool operator<(const Edge &that) const { |
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60 | return forward<that.forward || |
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61 | (!(that.forward<forward) && UndirEdge(*this)<UndirEdge(that)); |
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62 | } |
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63 | }; |
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64 | |
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65 | |
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66 | /// \brief Returns the Edge of opposite direction. |
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67 | /// |
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68 | /// \bug Is this a good name for this? Or "reverse" is better? |
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69 | Edge opposite(const Edge &e) const { |
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70 | return Edge(e,!e.forward); |
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71 | } |
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72 | |
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73 | protected: |
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74 | |
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75 | template <typename E> |
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76 | Node _dirSource(const E &e) const { |
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77 | return e.forward ? Parent::source(e) : Parent::target(e); |
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78 | } |
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79 | |
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80 | template <typename E> |
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81 | Node _dirTarget(const E &e) const { |
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82 | return e.forward ? Parent::target(e) : Parent::source(e); |
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83 | } |
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84 | |
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85 | public: |
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86 | /// \todo Shouldn't the "source" of an undirected edge be called "aNode" |
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87 | /// or something??? |
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88 | using Parent::source; |
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89 | |
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90 | /// Source of the given Edge. |
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91 | Node source(const Edge &e) const { |
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92 | return _dirSource(e); |
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93 | } |
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94 | |
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95 | /// \todo Shouldn't the "target" of an undirected edge be called "bNode" |
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96 | /// or something??? |
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97 | using Parent::target; |
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98 | |
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99 | /// Target of the given Edge. |
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100 | Node target(const Edge &e) const { |
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101 | return _dirTarget(e); |
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102 | } |
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103 | |
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104 | /// Returns whether the given directed edge is same orientation as the |
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105 | /// corresponding undirected edge. |
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106 | /// |
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107 | /// \todo reference to the corresponding point of the undirected graph |
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108 | /// concept. "What does the direction of an undirected edge mean?" |
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109 | bool forward(const Edge &e) const { return e.forward; } |
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110 | |
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111 | Node oppositeNode(const Node &n, const UndirEdge &e) const { |
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112 | if( n == Parent::source(e)) |
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113 | return Parent::target(e); |
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114 | else if( n == Parent::target(e)) |
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115 | return Parent::source(e); |
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116 | else |
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117 | return INVALID; |
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118 | } |
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119 | |
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120 | |
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121 | using Parent::first; |
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122 | void first(Edge &e) const { |
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123 | Parent::first(e); |
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124 | e.forward=true; |
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125 | } |
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126 | |
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127 | using Parent::next; |
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128 | void next(Edge &e) const { |
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129 | if( e.forward ) { |
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130 | e.forward = false; |
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131 | } |
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132 | else { |
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133 | Parent::next(e); |
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134 | e.forward = true; |
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135 | } |
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136 | } |
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137 | |
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138 | |
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139 | protected: |
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140 | |
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141 | template <typename E> |
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142 | void _dirFirstOut(E &e, const Node &n) const { |
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143 | Parent::firstOut(e,n); |
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144 | if( UndirEdge(e) != INVALID ) { |
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145 | e.forward = true; |
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146 | } |
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147 | else { |
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148 | Parent::firstIn(e,n); |
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149 | e.forward = false; |
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150 | } |
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151 | } |
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152 | template <typename E> |
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153 | void _dirFirstIn(E &e, const Node &n) const { |
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154 | Parent::firstIn(e,n); |
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155 | if( UndirEdge(e) != INVALID ) { |
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156 | e.forward = true; |
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157 | } |
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158 | else { |
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159 | Parent::firstOut(e,n); |
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160 | e.forward = false; |
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161 | } |
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162 | } |
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163 | |
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164 | template <typename E> |
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165 | void _dirNextOut(E &e) const { |
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166 | if( e.forward ) { |
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167 | Parent::nextOut(e); |
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168 | if( UndirEdge(e) == INVALID ) { |
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169 | Parent::firstIn(e, Parent::source(e)); |
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170 | e.forward = false; |
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171 | } |
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172 | } |
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173 | else { |
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174 | Parent::nextIn(e); |
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175 | } |
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176 | } |
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177 | template <typename E> |
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178 | void _dirNextIn(E &e) const { |
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179 | if( e.forward ) { |
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180 | Parent::nextIn(e); |
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181 | if( UndirEdge(e) == INVALID ) { |
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182 | Parent::firstOut(e, Parent::target(e)); |
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183 | e.forward = false; |
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184 | } |
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185 | } |
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186 | else { |
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187 | Parent::nextOut(e); |
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188 | } |
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189 | } |
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190 | |
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191 | public: |
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192 | |
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193 | void firstOut(Edge &e, const Node &n) const { |
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194 | _dirFirstOut(e, n); |
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195 | } |
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196 | void firstIn(Edge &e, const Node &n) const { |
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197 | _dirFirstIn(e, n); |
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198 | } |
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199 | |
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200 | void nextOut(Edge &e) const { |
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201 | _dirNextOut(e); |
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202 | } |
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203 | void nextIn(Edge &e) const { |
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204 | _dirNextIn(e); |
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205 | } |
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206 | |
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207 | // Miscellaneous stuff: |
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208 | |
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209 | /// \todo these methods (id, maxEdgeId) should be moved into separate |
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210 | /// Extender |
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211 | |
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212 | // using Parent::id; |
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213 | // Using "using" is not a good idea, cause it could be that there is |
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214 | // no "id" in Parent... |
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215 | |
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216 | int id(const Node &n) const { |
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217 | return Parent::id(n); |
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218 | } |
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219 | |
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220 | int id(const UndirEdge &e) const { |
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221 | return Parent::id(e); |
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222 | } |
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223 | |
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224 | int id(const Edge &e) const { |
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225 | return 2 * Parent::id(e) + int(e.forward); |
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226 | } |
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227 | |
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228 | |
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229 | int maxId(Node n) const { |
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230 | return Parent::maxId(Node()); |
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231 | } |
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232 | |
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233 | int maxId(Edge) const { |
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234 | return 2 * Parent::maxId(typename Parent::Edge()) + 1; |
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235 | } |
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236 | int maxId(UndirEdge) const { |
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237 | return Parent::maxId(typename Parent::Edge()); |
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238 | } |
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239 | |
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240 | }; |
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241 | |
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242 | } |
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243 | |
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244 | #endif // LEMON_UNDIR_GRAPH_EXTENDER_H |
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