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 | public: |
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46 | Edge() {} |
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47 | |
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48 | /// \brief Directed edge from undirected edge and a direction. |
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49 | /// |
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50 | /// This constructor is not a part of the concept interface of |
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51 | /// undirected graph, so please avoid using it if possible! |
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52 | Edge(const UndirEdge &ue, bool _forward) : |
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53 | UndirEdge(ue), forward(_forward) {} |
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54 | |
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55 | /// \brief Directed edge from undirected edge and a source node. |
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56 | /// |
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57 | /// Constructs a directed edge from undirected edge and a source node. |
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58 | /// |
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59 | /// \note You have to specify the graph for this constructor. |
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60 | Edge(const Graph &g, const UndirEdge &ue, const Node &n) : |
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61 | UndirEdge(ue) { forward = (g.source(ue) == n); } |
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62 | |
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63 | /// Invalid edge constructor |
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64 | Edge(Invalid i) : UndirEdge(i), forward(true) {} |
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65 | |
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66 | bool operator==(const Edge &that) const { |
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67 | return forward==that.forward && UndirEdge(*this)==UndirEdge(that); |
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68 | } |
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69 | bool operator!=(const Edge &that) const { |
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70 | return forward!=that.forward || UndirEdge(*this)!=UndirEdge(that); |
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71 | } |
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72 | bool operator<(const Edge &that) const { |
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73 | return forward<that.forward || |
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74 | (!(that.forward<forward) && UndirEdge(*this)<UndirEdge(that)); |
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75 | } |
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76 | }; |
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77 | |
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78 | |
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79 | /// \brief Edge of opposite direction. |
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80 | /// |
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81 | /// Returns the Edge of opposite direction. |
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82 | Edge opposite(const Edge &e) const { |
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83 | return Edge(e,!e.forward); |
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84 | } |
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85 | |
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86 | protected: |
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87 | |
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88 | template <typename E> |
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89 | Node _dirSource(const E &e) const { |
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90 | return e.forward ? Parent::source(e) : Parent::target(e); |
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91 | } |
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92 | |
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93 | template <typename E> |
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94 | Node _dirTarget(const E &e) const { |
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95 | return e.forward ? Parent::target(e) : Parent::source(e); |
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96 | } |
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97 | |
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98 | public: |
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99 | /// \todo Shouldn't the "source" of an undirected edge be called "aNode" |
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100 | /// or something??? |
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101 | using Parent::source; |
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102 | |
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103 | /// Source of the given Edge. |
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104 | Node source(const Edge &e) const { |
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105 | return _dirSource(e); |
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106 | } |
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107 | |
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108 | /// \todo Shouldn't the "target" of an undirected edge be called "bNode" |
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109 | /// or something??? |
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110 | using Parent::target; |
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111 | |
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112 | /// Target of the given Edge. |
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113 | Node target(const Edge &e) const { |
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114 | return _dirTarget(e); |
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115 | } |
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116 | |
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117 | /// Returns whether the given directed edge is same orientation as the |
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118 | /// corresponding undirected edge. |
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119 | /// |
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120 | /// \todo reference to the corresponding point of the undirected graph |
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121 | /// concept. "What does the direction of an undirected edge mean?" |
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122 | bool forward(const Edge &e) const { return e.forward; } |
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123 | |
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124 | Node oppositeNode(const Node &n, const UndirEdge &e) const { |
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125 | if( n == Parent::source(e)) |
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126 | return Parent::target(e); |
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127 | else if( n == Parent::target(e)) |
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128 | return Parent::source(e); |
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129 | else |
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130 | return INVALID; |
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131 | } |
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132 | |
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133 | /// Directed edge from an undirected edge and a source node. |
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134 | /// |
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135 | /// Returns a (directed) Edge corresponding to the specified UndirEdge |
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136 | /// and source Node. |
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137 | /// |
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138 | ///\todo Do we need this? |
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139 | /// |
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140 | ///\todo Better name... |
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141 | Edge edgeWithSource(const UndirEdge &ue, const Node &s) const { |
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142 | return Edge(*this, ue, s); |
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143 | } |
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144 | |
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145 | using Parent::first; |
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146 | void first(Edge &e) const { |
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147 | Parent::first(e); |
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148 | e.forward=true; |
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149 | } |
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150 | |
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151 | using Parent::next; |
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152 | void next(Edge &e) const { |
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153 | if( e.forward ) { |
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154 | e.forward = false; |
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155 | } |
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156 | else { |
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157 | Parent::next(e); |
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158 | e.forward = true; |
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159 | } |
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160 | } |
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161 | |
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162 | |
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163 | protected: |
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164 | |
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165 | template <typename E> |
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166 | void _dirFirstOut(E &e, const Node &n) const { |
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167 | Parent::firstIn(e,n); |
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168 | if( UndirEdge(e) != INVALID ) { |
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169 | e.forward = false; |
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170 | } |
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171 | else { |
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172 | Parent::firstOut(e,n); |
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173 | e.forward = true; |
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174 | } |
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175 | } |
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176 | template <typename E> |
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177 | void _dirFirstIn(E &e, const Node &n) const { |
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178 | Parent::firstOut(e,n); |
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179 | if( UndirEdge(e) != INVALID ) { |
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180 | e.forward = false; |
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181 | } |
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182 | else { |
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183 | Parent::firstIn(e,n); |
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184 | e.forward = true; |
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185 | } |
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186 | } |
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187 | |
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188 | template <typename E> |
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189 | void _dirNextOut(E &e) const { |
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190 | if( ! e.forward ) { |
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191 | Node n = Parent::target(e); |
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192 | Parent::nextIn(e); |
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193 | if( UndirEdge(e) == INVALID ) { |
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194 | Parent::firstOut(e, n); |
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195 | e.forward = true; |
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196 | } |
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197 | } |
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198 | else { |
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199 | Parent::nextOut(e); |
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200 | } |
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201 | } |
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202 | template <typename E> |
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203 | void _dirNextIn(E &e) const { |
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204 | if( ! e.forward ) { |
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205 | Node n = Parent::source(e); |
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206 | Parent::nextOut(e); |
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207 | if( UndirEdge(e) == INVALID ) { |
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208 | Parent::firstIn(e, n); |
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209 | e.forward = true; |
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210 | } |
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211 | } |
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212 | else { |
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213 | Parent::nextIn(e); |
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214 | } |
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215 | } |
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216 | |
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217 | public: |
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218 | |
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219 | void firstOut(Edge &e, const Node &n) const { |
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220 | _dirFirstOut(e, n); |
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221 | } |
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222 | void firstIn(Edge &e, const Node &n) const { |
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223 | _dirFirstIn(e, n); |
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224 | } |
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225 | |
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226 | void nextOut(Edge &e) const { |
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227 | _dirNextOut(e); |
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228 | } |
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229 | void nextIn(Edge &e) const { |
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230 | _dirNextIn(e); |
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231 | } |
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232 | |
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233 | // Miscellaneous stuff: |
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234 | |
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235 | /// \todo these methods (id, maxEdgeId) should be moved into separate |
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236 | /// Extender |
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237 | |
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238 | // using Parent::id; |
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239 | // Using "using" is not a good idea, cause it could be that there is |
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240 | // no "id" in Parent... |
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241 | |
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242 | int id(const Node &n) const { |
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243 | return Parent::id(n); |
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244 | } |
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245 | |
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246 | int id(const UndirEdge &e) const { |
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247 | return Parent::id(e); |
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248 | } |
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249 | |
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250 | int id(const Edge &e) const { |
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251 | return 2 * Parent::id(e) + int(e.forward); |
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252 | } |
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253 | |
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254 | |
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255 | int maxId(Node) const { |
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256 | return Parent::maxId(Node()); |
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257 | } |
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258 | |
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259 | int maxId(Edge) const { |
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260 | return 2 * Parent::maxId(typename Parent::Edge()) + 1; |
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261 | } |
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262 | int maxId(UndirEdge) const { |
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263 | return Parent::maxId(typename Parent::Edge()); |
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264 | } |
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265 | |
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266 | |
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267 | int edgeNum() const { |
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268 | return 2 * Parent::edgeNum(); |
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269 | } |
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270 | int undirEdgeNum() const { |
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271 | return Parent::edgeNum(); |
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272 | } |
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273 | |
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274 | }; |
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275 | |
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276 | } |
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277 | |
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278 | #endif // LEMON_UNDIR_GRAPH_EXTENDER_H |
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