1 | /* -*- C++ -*- |
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2 | * lemon/matrix_graph.h - Part of LEMON, a generic C++ optimization library |
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3 | * |
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4 | * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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5 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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6 | * |
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7 | * Permission to use, modify and distribute this software is granted |
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8 | * provided that this copyright notice appears in all copies. For |
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9 | * precise terms see the accompanying LICENSE file. |
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10 | * |
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11 | * This software is provided "AS IS" with no warranty of any kind, |
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12 | * express or implied, and with no claim as to its suitability for any |
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13 | * purpose. |
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14 | * |
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15 | */ |
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16 | |
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17 | #ifndef MATRIX_GRAPH_H |
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18 | #define MATRIX_GRAPH_H |
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19 | |
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20 | #include <iostream> |
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21 | #include <lemon/invalid.h> |
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22 | #include <lemon/utility.h> |
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23 | |
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24 | #include <lemon/bits/iterable_graph_extender.h> |
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25 | #include <lemon/bits/alteration_notifier.h> |
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26 | #include <lemon/bits/default_map.h> |
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27 | |
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28 | #include <lemon/bits/undir_graph_extender.h> |
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29 | |
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30 | namespace lemon { |
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31 | |
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32 | class MatrixGraphBase { |
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33 | |
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34 | public: |
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35 | |
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36 | typedef MatrixGraphBase Graph; |
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37 | |
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38 | class Node; |
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39 | class Edge; |
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40 | |
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41 | public: |
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42 | |
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43 | MatrixGraphBase() {} |
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44 | |
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45 | ///Creates a full graph with \c n nodes. |
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46 | void construct(int height, int width) { |
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47 | _height = height; _width = width; |
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48 | _nodeNum = height * width; _edgeNum = 2 * _nodeNum - width - height; |
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49 | _edgeLimit = _nodeNum - width; |
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50 | } |
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51 | |
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52 | Node operator()(int i, int j) const { |
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53 | return Node(i * _width + j); |
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54 | } |
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55 | |
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56 | int width() const { |
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57 | return _width; |
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58 | } |
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59 | |
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60 | int height() const { |
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61 | return _height; |
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62 | } |
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63 | |
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64 | typedef True NodeNumTag; |
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65 | typedef True EdgeNumTag; |
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66 | |
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67 | ///Number of nodes. |
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68 | int nodeNum() const { return _nodeNum; } |
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69 | ///Number of edges. |
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70 | int edgeNum() const { return _edgeNum; } |
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71 | |
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72 | /// Maximum node ID. |
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73 | |
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74 | /// Maximum node ID. |
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75 | ///\sa id(Node) |
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76 | int maxId(Node = INVALID) const { return nodeNum() - 1; } |
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77 | /// Maximum edge ID. |
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78 | |
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79 | /// Maximum edge ID. |
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80 | ///\sa id(Edge) |
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81 | int maxId(Edge = INVALID) const { return edgeNum() - 1; } |
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82 | |
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83 | Node source(Edge e) const { |
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84 | if (e.id < _edgeLimit) { |
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85 | return e.id; |
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86 | } else { |
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87 | return (e.id - _edgeLimit) % (_width - 1) + |
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88 | (e.id - _edgeLimit) / (_width - 1) * _width; |
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89 | } |
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90 | } |
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91 | |
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92 | Node target(Edge e) const { |
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93 | if (e.id < _edgeLimit) { |
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94 | return e.id + _width; |
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95 | } else { |
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96 | return (e.id - _edgeLimit) % (_width - 1) + |
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97 | (e.id - _edgeLimit) / (_width - 1) * _width + 1; |
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98 | } |
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99 | } |
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100 | |
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101 | /// Node ID. |
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102 | |
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103 | /// The ID of a valid Node is a nonnegative integer not greater than |
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104 | /// \ref maxNodeId(). The range of the ID's is not surely continuous |
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105 | /// and the greatest node ID can be actually less then \ref maxNodeId(). |
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106 | /// |
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107 | /// The ID of the \ref INVALID node is -1. |
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108 | ///\return The ID of the node \c v. |
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109 | |
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110 | static int id(Node v) { return v.id; } |
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111 | /// Edge ID. |
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112 | |
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113 | /// The ID of a valid Edge is a nonnegative integer not greater than |
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114 | /// \ref maxEdgeId(). The range of the ID's is not surely continuous |
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115 | /// and the greatest edge ID can be actually less then \ref maxEdgeId(). |
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116 | /// |
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117 | /// The ID of the \ref INVALID edge is -1. |
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118 | ///\return The ID of the edge \c e. |
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119 | static int id(Edge e) { return e.id; } |
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120 | |
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121 | static Node fromId(int id, Node) { return Node(id);} |
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122 | |
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123 | static Edge fromId(int id, Edge) { return Edge(id);} |
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124 | |
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125 | typedef True FindEdgeTag; |
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126 | |
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127 | /// Finds an edge between two nodes. |
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128 | |
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129 | /// Finds an edge from node \c u to node \c v. |
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130 | /// |
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131 | /// If \c prev is \ref INVALID (this is the default value), then |
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132 | /// It finds the first edge from \c u to \c v. Otherwise it looks for |
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133 | /// the next edge from \c u to \c v after \c prev. |
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134 | /// \return The found edge or INVALID if there is no such an edge. |
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135 | Edge findEdge(Node u, Node v, Edge prev = INVALID) { |
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136 | if (prev != INVALID) return INVALID; |
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137 | if (v.id - u.id == _width) return Edge(u.id); |
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138 | if (v.id - u.id == 1 && u.id % _width < _width - 1) { |
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139 | return Edge(u.id / _width * (_width - 1) + |
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140 | u.id % _width + _edgeLimit); |
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141 | } |
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142 | return INVALID; |
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143 | } |
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144 | |
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145 | |
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146 | class Node { |
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147 | friend class MatrixGraphBase; |
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148 | |
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149 | protected: |
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150 | int id; |
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151 | Node(int _id) { id = _id;} |
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152 | public: |
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153 | Node() {} |
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154 | Node (Invalid) { id = -1; } |
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155 | bool operator==(const Node node) const {return id == node.id;} |
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156 | bool operator!=(const Node node) const {return id != node.id;} |
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157 | bool operator<(const Node node) const {return id < node.id;} |
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158 | }; |
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159 | |
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160 | |
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161 | |
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162 | class Edge { |
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163 | friend class MatrixGraphBase; |
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164 | |
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165 | protected: |
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166 | int id; |
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167 | |
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168 | Edge(int _id) : id(_id) {} |
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169 | |
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170 | public: |
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171 | Edge() { } |
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172 | Edge (Invalid) { id = -1; } |
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173 | bool operator==(const Edge edge) const {return id == edge.id;} |
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174 | bool operator!=(const Edge edge) const {return id != edge.id;} |
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175 | bool operator<(const Edge edge) const {return id < edge.id;} |
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176 | }; |
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177 | |
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178 | void first(Node& node) const { |
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179 | node.id = nodeNum() - 1; |
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180 | } |
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181 | |
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182 | static void next(Node& node) { |
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183 | --node.id; |
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184 | } |
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185 | |
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186 | void first(Edge& edge) const { |
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187 | edge.id = edgeNum() - 1; |
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188 | } |
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189 | |
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190 | static void next(Edge& edge) { |
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191 | --edge.id; |
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192 | } |
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193 | |
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194 | void firstOut(Edge& edge, const Node& node) const { |
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195 | if (node.id < _nodeNum - _width) { |
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196 | edge.id = node.id; |
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197 | } else if (node.id % _width < _width - 1) { |
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198 | edge.id = _edgeLimit + node.id % _width + |
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199 | (node.id / _width) * (_width - 1); |
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200 | } else { |
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201 | edge.id = -1; |
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202 | } |
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203 | } |
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204 | |
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205 | void nextOut(Edge& edge) const { |
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206 | if (edge.id >= _edgeLimit) { |
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207 | edge.id = -1; |
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208 | } else if (edge.id % _width < _width - 1) { |
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209 | edge.id = _edgeLimit + edge.id % _width + |
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210 | (edge.id / _width) * (_width - 1); |
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211 | } else { |
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212 | edge.id = -1; |
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213 | } |
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214 | } |
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215 | |
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216 | void firstIn(Edge& edge, const Node& node) const { |
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217 | if (node.id >= _width) { |
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218 | edge.id = node.id - _width; |
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219 | } else if (node.id % _width > 0) { |
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220 | edge.id = _edgeLimit + node.id % _width + |
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221 | (node.id / _width) * (_width - 1) - 1; |
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222 | } else { |
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223 | edge.id = -1; |
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224 | } |
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225 | } |
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226 | |
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227 | void nextIn(Edge& edge) const { |
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228 | if (edge.id >= _edgeLimit) { |
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229 | edge.id = -1; |
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230 | } else if (edge.id % _width > 0) { |
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231 | edge.id = _edgeLimit + edge.id % _width + |
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232 | (edge.id / _width + 1) * (_width - 1) - 1; |
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233 | } else { |
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234 | edge.id = -1; |
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235 | } |
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236 | } |
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237 | |
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238 | private: |
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239 | int _width, _height; |
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240 | int _nodeNum, _edgeNum; |
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241 | int _edgeLimit; |
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242 | }; |
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243 | |
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244 | |
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245 | typedef UndirGraphExtender<MatrixGraphBase> |
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246 | UndirMatrixGraphBase; |
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247 | typedef AlterableUndirGraphExtender<UndirMatrixGraphBase> |
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248 | AlterableMatrixGraphBase; |
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249 | typedef IterableUndirGraphExtender<AlterableMatrixGraphBase> |
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250 | IterableMatrixGraphBase; |
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251 | typedef MappableUndirGraphExtender<IterableMatrixGraphBase> |
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252 | MappableMatrixGraphBase; |
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253 | |
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254 | /// \ingroup graphs |
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255 | /// |
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256 | /// \brief Matrix graph class |
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257 | /// |
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258 | /// This class implements a special graph type. The nodes of the |
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259 | /// graph can be indiced by two integer \c (i,j) value where \c i |
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260 | /// is in the \c [0,height) range and j is in the [0, width) range. |
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261 | /// Two nodes are connected in the graph if the indices differ only |
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262 | /// on one position and only one is the difference. |
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263 | /// |
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264 | /// The graph can be indiced in the next way: |
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265 | /// \code |
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266 | /// MatrixGraph graph(h, w); |
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267 | /// MatrixGraph::NodeMap<int> val(graph); |
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268 | /// for (int i = 0; i < graph.height(); ++i) { |
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269 | /// for (int j = 0; j < graph.width(); ++j) { |
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270 | /// val[graph(i, j)] = i + j; |
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271 | /// } |
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272 | /// } |
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273 | /// \endcode |
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274 | /// |
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275 | /// The graph type is fully conform to the \ref concept::UndirGraph |
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276 | /// "Undirected Graph" concept. |
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277 | /// |
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278 | /// \author Balazs Dezso |
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279 | class MatrixGraph : public MappableMatrixGraphBase { |
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280 | public: |
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281 | |
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282 | MatrixGraph(int m, int n) { construct(m, n); } |
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283 | }; |
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284 | } |
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285 | #endif |
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