1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
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2 | * |
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3 | * This file is a part of LEMON, a generic C++ optimization library. |
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4 | * |
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5 | * Copyright (C) 2003-2008 |
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6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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8 | * |
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9 | * Permission to use, modify and distribute this software is granted |
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10 | * provided that this copyright notice appears in all copies. For |
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11 | * precise terms see the accompanying LICENSE file. |
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12 | * |
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13 | * This software is provided "AS IS" with no warranty of any kind, |
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14 | * express or implied, and with no claim as to its suitability for any |
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15 | * purpose. |
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16 | * |
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17 | */ |
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18 | |
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19 | #ifndef LEMON_SMART_GRAPH_H |
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20 | #define LEMON_SMART_GRAPH_H |
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21 | |
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22 | ///\ingroup graphs |
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23 | ///\file |
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24 | ///\brief SmartDigraph and SmartGraph classes. |
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25 | |
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26 | #include <vector> |
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27 | |
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28 | #include <lemon/core.h> |
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29 | #include <lemon/error.h> |
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30 | #include <lemon/bits/graph_extender.h> |
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31 | |
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32 | namespace lemon { |
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33 | |
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34 | class SmartDigraph; |
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35 | ///Base of SmartDigraph |
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36 | |
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37 | ///Base of SmartDigraph |
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38 | /// |
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39 | class SmartDigraphBase { |
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40 | protected: |
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41 | |
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42 | struct NodeT |
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43 | { |
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44 | int first_in, first_out; |
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45 | NodeT() {} |
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46 | }; |
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47 | struct ArcT |
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48 | { |
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49 | int target, source, next_in, next_out; |
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50 | ArcT() {} |
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51 | }; |
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52 | |
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53 | std::vector<NodeT> nodes; |
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54 | std::vector<ArcT> arcs; |
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55 | |
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56 | public: |
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57 | |
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58 | typedef SmartDigraphBase Graph; |
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59 | |
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60 | class Node; |
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61 | class Arc; |
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62 | |
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63 | public: |
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64 | |
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65 | SmartDigraphBase() : nodes(), arcs() { } |
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66 | SmartDigraphBase(const SmartDigraphBase &_g) |
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67 | : nodes(_g.nodes), arcs(_g.arcs) { } |
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68 | |
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69 | typedef True NodeNumTag; |
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70 | typedef True EdgeNumTag; |
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71 | |
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72 | int nodeNum() const { return nodes.size(); } |
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73 | int arcNum() const { return arcs.size(); } |
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74 | |
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75 | int maxNodeId() const { return nodes.size()-1; } |
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76 | int maxArcId() const { return arcs.size()-1; } |
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77 | |
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78 | Node addNode() { |
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79 | int n = nodes.size(); |
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80 | nodes.push_back(NodeT()); |
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81 | nodes[n].first_in = -1; |
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82 | nodes[n].first_out = -1; |
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83 | return Node(n); |
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84 | } |
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85 | |
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86 | Arc addArc(Node u, Node v) { |
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87 | int n = arcs.size(); |
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88 | arcs.push_back(ArcT()); |
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89 | arcs[n].source = u._id; |
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90 | arcs[n].target = v._id; |
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91 | arcs[n].next_out = nodes[u._id].first_out; |
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92 | arcs[n].next_in = nodes[v._id].first_in; |
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93 | nodes[u._id].first_out = nodes[v._id].first_in = n; |
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94 | |
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95 | return Arc(n); |
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96 | } |
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97 | |
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98 | void clear() { |
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99 | arcs.clear(); |
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100 | nodes.clear(); |
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101 | } |
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102 | |
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103 | Node source(Arc a) const { return Node(arcs[a._id].source); } |
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104 | Node target(Arc a) const { return Node(arcs[a._id].target); } |
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105 | |
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106 | static int id(Node v) { return v._id; } |
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107 | static int id(Arc a) { return a._id; } |
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108 | |
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109 | static Node nodeFromId(int id) { return Node(id);} |
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110 | static Arc arcFromId(int id) { return Arc(id);} |
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111 | |
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112 | bool valid(Node n) const { |
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113 | return n._id >= 0 && n._id < static_cast<int>(nodes.size()); |
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114 | } |
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115 | bool valid(Arc a) const { |
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116 | return a._id >= 0 && a._id < static_cast<int>(arcs.size()); |
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117 | } |
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118 | |
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119 | class Node { |
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120 | friend class SmartDigraphBase; |
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121 | friend class SmartDigraph; |
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122 | |
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123 | protected: |
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124 | int _id; |
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125 | explicit Node(int id) : _id(id) {} |
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126 | public: |
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127 | Node() {} |
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128 | Node (Invalid) : _id(-1) {} |
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129 | bool operator==(const Node i) const {return _id == i._id;} |
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130 | bool operator!=(const Node i) const {return _id != i._id;} |
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131 | bool operator<(const Node i) const {return _id < i._id;} |
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132 | }; |
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133 | |
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134 | |
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135 | class Arc { |
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136 | friend class SmartDigraphBase; |
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137 | friend class SmartDigraph; |
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138 | |
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139 | protected: |
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140 | int _id; |
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141 | explicit Arc(int id) : _id(id) {} |
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142 | public: |
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143 | Arc() { } |
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144 | Arc (Invalid) : _id(-1) {} |
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145 | bool operator==(const Arc i) const {return _id == i._id;} |
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146 | bool operator!=(const Arc i) const {return _id != i._id;} |
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147 | bool operator<(const Arc i) const {return _id < i._id;} |
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148 | }; |
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149 | |
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150 | void first(Node& node) const { |
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151 | node._id = nodes.size() - 1; |
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152 | } |
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153 | |
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154 | static void next(Node& node) { |
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155 | --node._id; |
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156 | } |
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157 | |
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158 | void first(Arc& arc) const { |
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159 | arc._id = arcs.size() - 1; |
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160 | } |
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161 | |
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162 | static void next(Arc& arc) { |
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163 | --arc._id; |
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164 | } |
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165 | |
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166 | void firstOut(Arc& arc, const Node& node) const { |
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167 | arc._id = nodes[node._id].first_out; |
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168 | } |
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169 | |
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170 | void nextOut(Arc& arc) const { |
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171 | arc._id = arcs[arc._id].next_out; |
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172 | } |
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173 | |
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174 | void firstIn(Arc& arc, const Node& node) const { |
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175 | arc._id = nodes[node._id].first_in; |
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176 | } |
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177 | |
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178 | void nextIn(Arc& arc) const { |
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179 | arc._id = arcs[arc._id].next_in; |
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180 | } |
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181 | |
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182 | }; |
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183 | |
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184 | typedef DigraphExtender<SmartDigraphBase> ExtendedSmartDigraphBase; |
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185 | |
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186 | ///\ingroup graphs |
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187 | /// |
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188 | ///\brief A smart directed graph class. |
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189 | /// |
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190 | ///This is a simple and fast digraph implementation. |
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191 | ///It is also quite memory efficient, but at the price |
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192 | ///that <b> it does support only limited (only stack-like) |
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193 | ///node and arc deletions</b>. |
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194 | ///It conforms to the \ref concepts::Digraph "Digraph concept" with |
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195 | ///an important extra feature that its maps are real \ref |
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196 | ///concepts::ReferenceMap "reference map"s. |
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197 | /// |
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198 | ///\sa concepts::Digraph. |
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199 | class SmartDigraph : public ExtendedSmartDigraphBase { |
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200 | public: |
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201 | |
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202 | typedef ExtendedSmartDigraphBase Parent; |
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203 | |
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204 | private: |
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205 | |
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206 | ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead. |
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207 | |
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208 | ///SmartDigraph is \e not copy constructible. Use DigraphCopy() instead. |
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209 | /// |
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210 | SmartDigraph(const SmartDigraph &) : ExtendedSmartDigraphBase() {}; |
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211 | ///\brief Assignment of SmartDigraph to another one is \e not allowed. |
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212 | ///Use DigraphCopy() instead. |
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213 | |
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214 | ///Assignment of SmartDigraph to another one is \e not allowed. |
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215 | ///Use DigraphCopy() instead. |
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216 | void operator=(const SmartDigraph &) {} |
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217 | |
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218 | public: |
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219 | |
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220 | /// Constructor |
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221 | |
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222 | /// Constructor. |
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223 | /// |
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224 | SmartDigraph() {}; |
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225 | |
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226 | ///Add a new node to the digraph. |
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227 | |
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228 | /// \return the new node. |
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229 | /// |
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230 | Node addNode() { return Parent::addNode(); } |
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231 | |
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232 | ///Add a new arc to the digraph. |
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233 | |
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234 | ///Add a new arc to the digraph with source node \c s |
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235 | ///and target node \c t. |
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236 | ///\return the new arc. |
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237 | Arc addArc(const Node& s, const Node& t) { |
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238 | return Parent::addArc(s, t); |
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239 | } |
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240 | |
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241 | /// \brief Using this it is possible to avoid the superfluous memory |
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242 | /// allocation. |
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243 | |
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244 | /// Using this it is possible to avoid the superfluous memory |
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245 | /// allocation: if you know that the digraph you want to build will |
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246 | /// be very large (e.g. it will contain millions of nodes and/or arcs) |
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247 | /// then it is worth reserving space for this amount before starting |
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248 | /// to build the digraph. |
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249 | /// \sa reserveArc |
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250 | void reserveNode(int n) { nodes.reserve(n); }; |
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251 | |
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252 | /// \brief Using this it is possible to avoid the superfluous memory |
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253 | /// allocation. |
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254 | |
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255 | /// Using this it is possible to avoid the superfluous memory |
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256 | /// allocation: if you know that the digraph you want to build will |
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257 | /// be very large (e.g. it will contain millions of nodes and/or arcs) |
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258 | /// then it is worth reserving space for this amount before starting |
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259 | /// to build the digraph. |
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260 | /// \sa reserveNode |
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261 | void reserveArc(int m) { arcs.reserve(m); }; |
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262 | |
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263 | /// \brief Node validity check |
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264 | /// |
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265 | /// This function gives back true if the given node is valid, |
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266 | /// ie. it is a real node of the graph. |
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267 | /// |
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268 | /// \warning A removed node (using Snapshot) could become valid again |
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269 | /// when new nodes are added to the graph. |
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270 | bool valid(Node n) const { return Parent::valid(n); } |
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271 | |
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272 | /// \brief Arc validity check |
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273 | /// |
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274 | /// This function gives back true if the given arc is valid, |
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275 | /// ie. it is a real arc of the graph. |
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276 | /// |
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277 | /// \warning A removed arc (using Snapshot) could become valid again |
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278 | /// when new arcs are added to the graph. |
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279 | bool valid(Arc a) const { return Parent::valid(a); } |
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280 | |
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281 | ///Clear the digraph. |
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282 | |
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283 | ///Erase all the nodes and arcs from the digraph. |
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284 | /// |
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285 | void clear() { |
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286 | Parent::clear(); |
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287 | } |
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288 | |
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289 | ///Split a node. |
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290 | |
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291 | ///This function splits a node. First a new node is added to the digraph, |
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292 | ///then the source of each outgoing arc of \c n is moved to this new node. |
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293 | ///If \c connect is \c true (this is the default value), then a new arc |
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294 | ///from \c n to the newly created node is also added. |
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295 | ///\return The newly created node. |
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296 | /// |
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297 | ///\note The <tt>Arc</tt>s |
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298 | ///referencing a moved arc remain |
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299 | ///valid. However <tt>InArc</tt>'s and <tt>OutArc</tt>'s |
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300 | ///may be invalidated. |
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301 | ///\warning This functionality cannot be used together with the Snapshot |
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302 | ///feature. |
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303 | Node split(Node n, bool connect = true) |
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304 | { |
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305 | Node b = addNode(); |
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306 | nodes[b._id].first_out=nodes[n._id].first_out; |
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307 | nodes[n._id].first_out=-1; |
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308 | for(int i=nodes[b._id].first_out; i!=-1; i=arcs[i].next_out) { |
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309 | arcs[i].source=b._id; |
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310 | } |
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311 | if(connect) addArc(n,b); |
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312 | return b; |
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313 | } |
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314 | |
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315 | public: |
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316 | |
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317 | class Snapshot; |
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318 | |
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319 | protected: |
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320 | |
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321 | void restoreSnapshot(const Snapshot &s) |
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322 | { |
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323 | while(s.arc_num<arcs.size()) { |
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324 | Arc arc = arcFromId(arcs.size()-1); |
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325 | Parent::notifier(Arc()).erase(arc); |
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326 | nodes[arcs.back().source].first_out=arcs.back().next_out; |
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327 | nodes[arcs.back().target].first_in=arcs.back().next_in; |
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328 | arcs.pop_back(); |
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329 | } |
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330 | while(s.node_num<nodes.size()) { |
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331 | Node node = nodeFromId(nodes.size()-1); |
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332 | Parent::notifier(Node()).erase(node); |
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333 | nodes.pop_back(); |
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334 | } |
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335 | } |
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336 | |
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337 | public: |
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338 | |
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339 | ///Class to make a snapshot of the digraph and to restrore to it later. |
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340 | |
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341 | ///Class to make a snapshot of the digraph and to restrore to it later. |
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342 | /// |
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343 | ///The newly added nodes and arcs can be removed using the |
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344 | ///restore() function. |
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345 | ///\note After you restore a state, you cannot restore |
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346 | ///a later state, in other word you cannot add again the arcs deleted |
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347 | ///by restore() using another one Snapshot instance. |
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348 | /// |
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349 | ///\warning If you do not use correctly the snapshot that can cause |
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350 | ///either broken program, invalid state of the digraph, valid but |
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351 | ///not the restored digraph or no change. Because the runtime performance |
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352 | ///the validity of the snapshot is not stored. |
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353 | class Snapshot |
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354 | { |
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355 | SmartDigraph *_graph; |
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356 | protected: |
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357 | friend class SmartDigraph; |
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358 | unsigned int node_num; |
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359 | unsigned int arc_num; |
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360 | public: |
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361 | ///Default constructor. |
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362 | |
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363 | ///Default constructor. |
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364 | ///To actually make a snapshot you must call save(). |
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365 | /// |
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366 | Snapshot() : _graph(0) {} |
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367 | ///Constructor that immediately makes a snapshot |
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368 | |
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369 | ///This constructor immediately makes a snapshot of the digraph. |
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370 | ///\param graph The digraph we make a snapshot of. |
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371 | Snapshot(SmartDigraph &graph) : _graph(&graph) { |
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372 | node_num=_graph->nodes.size(); |
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373 | arc_num=_graph->arcs.size(); |
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374 | } |
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375 | |
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376 | ///Make a snapshot. |
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377 | |
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378 | ///Make a snapshot of the digraph. |
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379 | /// |
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380 | ///This function can be called more than once. In case of a repeated |
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381 | ///call, the previous snapshot gets lost. |
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382 | ///\param graph The digraph we make the snapshot of. |
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383 | void save(SmartDigraph &graph) |
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384 | { |
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385 | _graph=&graph; |
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386 | node_num=_graph->nodes.size(); |
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387 | arc_num=_graph->arcs.size(); |
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388 | } |
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389 | |
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390 | ///Undo the changes until a snapshot. |
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391 | |
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392 | ///Undo the changes until a snapshot created by save(). |
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393 | /// |
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394 | ///\note After you restored a state, you cannot restore |
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395 | ///a later state, in other word you cannot add again the arcs deleted |
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396 | ///by restore(). |
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397 | void restore() |
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398 | { |
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399 | _graph->restoreSnapshot(*this); |
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400 | } |
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401 | }; |
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402 | }; |
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403 | |
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404 | |
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405 | class SmartGraphBase { |
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406 | |
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407 | protected: |
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408 | |
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409 | struct NodeT { |
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410 | int first_out; |
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411 | }; |
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412 | |
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413 | struct ArcT { |
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414 | int target; |
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415 | int next_out; |
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416 | }; |
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417 | |
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418 | std::vector<NodeT> nodes; |
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419 | std::vector<ArcT> arcs; |
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420 | |
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421 | int first_free_arc; |
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422 | |
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423 | public: |
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424 | |
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425 | typedef SmartGraphBase Digraph; |
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426 | |
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427 | class Node; |
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428 | class Arc; |
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429 | class Edge; |
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430 | |
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431 | class Node { |
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432 | friend class SmartGraphBase; |
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433 | protected: |
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434 | |
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435 | int _id; |
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436 | explicit Node(int id) { _id = id;} |
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437 | |
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438 | public: |
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439 | Node() {} |
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440 | Node (Invalid) { _id = -1; } |
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441 | bool operator==(const Node& node) const {return _id == node._id;} |
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442 | bool operator!=(const Node& node) const {return _id != node._id;} |
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443 | bool operator<(const Node& node) const {return _id < node._id;} |
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444 | }; |
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445 | |
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446 | class Edge { |
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447 | friend class SmartGraphBase; |
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448 | protected: |
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449 | |
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450 | int _id; |
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451 | explicit Edge(int id) { _id = id;} |
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452 | |
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453 | public: |
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454 | Edge() {} |
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455 | Edge (Invalid) { _id = -1; } |
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456 | bool operator==(const Edge& arc) const {return _id == arc._id;} |
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457 | bool operator!=(const Edge& arc) const {return _id != arc._id;} |
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458 | bool operator<(const Edge& arc) const {return _id < arc._id;} |
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459 | }; |
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460 | |
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461 | class Arc { |
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462 | friend class SmartGraphBase; |
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463 | protected: |
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464 | |
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465 | int _id; |
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466 | explicit Arc(int id) { _id = id;} |
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467 | |
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468 | public: |
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469 | operator Edge() const { |
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470 | return _id != -1 ? edgeFromId(_id / 2) : INVALID; |
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471 | } |
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472 | |
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473 | Arc() {} |
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474 | Arc (Invalid) { _id = -1; } |
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475 | bool operator==(const Arc& arc) const {return _id == arc._id;} |
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476 | bool operator!=(const Arc& arc) const {return _id != arc._id;} |
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477 | bool operator<(const Arc& arc) const {return _id < arc._id;} |
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478 | }; |
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479 | |
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480 | |
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481 | |
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482 | SmartGraphBase() |
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483 | : nodes(), arcs() {} |
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484 | |
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485 | |
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486 | int maxNodeId() const { return nodes.size()-1; } |
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487 | int maxEdgeId() const { return arcs.size() / 2 - 1; } |
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488 | int maxArcId() const { return arcs.size()-1; } |
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489 | |
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490 | Node source(Arc e) const { return Node(arcs[e._id ^ 1].target); } |
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491 | Node target(Arc e) const { return Node(arcs[e._id].target); } |
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492 | |
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493 | Node u(Edge e) const { return Node(arcs[2 * e._id].target); } |
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494 | Node v(Edge e) const { return Node(arcs[2 * e._id + 1].target); } |
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495 | |
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496 | static bool direction(Arc e) { |
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497 | return (e._id & 1) == 1; |
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498 | } |
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499 | |
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500 | static Arc direct(Edge e, bool d) { |
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501 | return Arc(e._id * 2 + (d ? 1 : 0)); |
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502 | } |
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503 | |
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504 | void first(Node& node) const { |
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505 | node._id = nodes.size() - 1; |
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506 | } |
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507 | |
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508 | void next(Node& node) const { |
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509 | --node._id; |
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510 | } |
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511 | |
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512 | void first(Arc& arc) const { |
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513 | arc._id = arcs.size() - 1; |
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514 | } |
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515 | |
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516 | void next(Arc& arc) const { |
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517 | --arc._id; |
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518 | } |
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519 | |
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520 | void first(Edge& arc) const { |
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521 | arc._id = arcs.size() / 2 - 1; |
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522 | } |
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523 | |
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524 | void next(Edge& arc) const { |
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525 | --arc._id; |
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526 | } |
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527 | |
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528 | void firstOut(Arc &arc, const Node& v) const { |
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529 | arc._id = nodes[v._id].first_out; |
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530 | } |
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531 | void nextOut(Arc &arc) const { |
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532 | arc._id = arcs[arc._id].next_out; |
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533 | } |
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534 | |
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535 | void firstIn(Arc &arc, const Node& v) const { |
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536 | arc._id = ((nodes[v._id].first_out) ^ 1); |
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537 | if (arc._id == -2) arc._id = -1; |
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538 | } |
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539 | void nextIn(Arc &arc) const { |
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540 | arc._id = ((arcs[arc._id ^ 1].next_out) ^ 1); |
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541 | if (arc._id == -2) arc._id = -1; |
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542 | } |
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543 | |
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544 | void firstInc(Edge &arc, bool& d, const Node& v) const { |
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545 | int de = nodes[v._id].first_out; |
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546 | if (de != -1) { |
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547 | arc._id = de / 2; |
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548 | d = ((de & 1) == 1); |
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549 | } else { |
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550 | arc._id = -1; |
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551 | d = true; |
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552 | } |
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553 | } |
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554 | void nextInc(Edge &arc, bool& d) const { |
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555 | int de = (arcs[(arc._id * 2) | (d ? 1 : 0)].next_out); |
---|
556 | if (de != -1) { |
---|
557 | arc._id = de / 2; |
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558 | d = ((de & 1) == 1); |
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559 | } else { |
---|
560 | arc._id = -1; |
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561 | d = true; |
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562 | } |
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563 | } |
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564 | |
---|
565 | static int id(Node v) { return v._id; } |
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566 | static int id(Arc e) { return e._id; } |
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567 | static int id(Edge e) { return e._id; } |
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568 | |
---|
569 | static Node nodeFromId(int id) { return Node(id);} |
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570 | static Arc arcFromId(int id) { return Arc(id);} |
---|
571 | static Edge edgeFromId(int id) { return Edge(id);} |
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572 | |
---|
573 | bool valid(Node n) const { |
---|
574 | return n._id >= 0 && n._id < static_cast<int>(nodes.size()); |
---|
575 | } |
---|
576 | bool valid(Arc a) const { |
---|
577 | return a._id >= 0 && a._id < static_cast<int>(arcs.size()); |
---|
578 | } |
---|
579 | bool valid(Edge e) const { |
---|
580 | return e._id >= 0 && 2 * e._id < static_cast<int>(arcs.size()); |
---|
581 | } |
---|
582 | |
---|
583 | Node addNode() { |
---|
584 | int n = nodes.size(); |
---|
585 | nodes.push_back(NodeT()); |
---|
586 | nodes[n].first_out = -1; |
---|
587 | |
---|
588 | return Node(n); |
---|
589 | } |
---|
590 | |
---|
591 | Edge addEdge(Node u, Node v) { |
---|
592 | int n = arcs.size(); |
---|
593 | arcs.push_back(ArcT()); |
---|
594 | arcs.push_back(ArcT()); |
---|
595 | |
---|
596 | arcs[n].target = u._id; |
---|
597 | arcs[n | 1].target = v._id; |
---|
598 | |
---|
599 | arcs[n].next_out = nodes[v._id].first_out; |
---|
600 | nodes[v._id].first_out = n; |
---|
601 | |
---|
602 | arcs[n | 1].next_out = nodes[u._id].first_out; |
---|
603 | nodes[u._id].first_out = (n | 1); |
---|
604 | |
---|
605 | return Edge(n / 2); |
---|
606 | } |
---|
607 | |
---|
608 | void clear() { |
---|
609 | arcs.clear(); |
---|
610 | nodes.clear(); |
---|
611 | } |
---|
612 | |
---|
613 | }; |
---|
614 | |
---|
615 | typedef GraphExtender<SmartGraphBase> ExtendedSmartGraphBase; |
---|
616 | |
---|
617 | /// \ingroup graphs |
---|
618 | /// |
---|
619 | /// \brief A smart undirected graph class. |
---|
620 | /// |
---|
621 | /// This is a simple and fast graph implementation. |
---|
622 | /// It is also quite memory efficient, but at the price |
---|
623 | /// that <b> it does support only limited (only stack-like) |
---|
624 | /// node and arc deletions</b>. |
---|
625 | /// Except from this it conforms to |
---|
626 | /// the \ref concepts::Graph "Graph concept". |
---|
627 | /// |
---|
628 | /// It also has an |
---|
629 | /// important extra feature that |
---|
630 | /// its maps are real \ref concepts::ReferenceMap "reference map"s. |
---|
631 | /// |
---|
632 | /// \sa concepts::Graph. |
---|
633 | /// |
---|
634 | class SmartGraph : public ExtendedSmartGraphBase { |
---|
635 | private: |
---|
636 | |
---|
637 | ///SmartGraph is \e not copy constructible. Use GraphCopy() instead. |
---|
638 | |
---|
639 | ///SmartGraph is \e not copy constructible. Use GraphCopy() instead. |
---|
640 | /// |
---|
641 | SmartGraph(const SmartGraph &) : ExtendedSmartGraphBase() {}; |
---|
642 | |
---|
643 | ///\brief Assignment of SmartGraph to another one is \e not allowed. |
---|
644 | ///Use GraphCopy() instead. |
---|
645 | |
---|
646 | ///Assignment of SmartGraph to another one is \e not allowed. |
---|
647 | ///Use GraphCopy() instead. |
---|
648 | void operator=(const SmartGraph &) {} |
---|
649 | |
---|
650 | public: |
---|
651 | |
---|
652 | typedef ExtendedSmartGraphBase Parent; |
---|
653 | |
---|
654 | /// Constructor |
---|
655 | |
---|
656 | /// Constructor. |
---|
657 | /// |
---|
658 | SmartGraph() {} |
---|
659 | |
---|
660 | ///Add a new node to the graph. |
---|
661 | |
---|
662 | /// \return the new node. |
---|
663 | /// |
---|
664 | Node addNode() { return Parent::addNode(); } |
---|
665 | |
---|
666 | ///Add a new edge to the graph. |
---|
667 | |
---|
668 | ///Add a new edge to the graph with node \c s |
---|
669 | ///and \c t. |
---|
670 | ///\return the new edge. |
---|
671 | Edge addEdge(const Node& s, const Node& t) { |
---|
672 | return Parent::addEdge(s, t); |
---|
673 | } |
---|
674 | |
---|
675 | /// \brief Node validity check |
---|
676 | /// |
---|
677 | /// This function gives back true if the given node is valid, |
---|
678 | /// ie. it is a real node of the graph. |
---|
679 | /// |
---|
680 | /// \warning A removed node (using Snapshot) could become valid again |
---|
681 | /// when new nodes are added to the graph. |
---|
682 | bool valid(Node n) const { return Parent::valid(n); } |
---|
683 | |
---|
684 | /// \brief Arc validity check |
---|
685 | /// |
---|
686 | /// This function gives back true if the given arc is valid, |
---|
687 | /// ie. it is a real arc of the graph. |
---|
688 | /// |
---|
689 | /// \warning A removed arc (using Snapshot) could become valid again |
---|
690 | /// when new edges are added to the graph. |
---|
691 | bool valid(Arc a) const { return Parent::valid(a); } |
---|
692 | |
---|
693 | /// \brief Edge validity check |
---|
694 | /// |
---|
695 | /// This function gives back true if the given edge is valid, |
---|
696 | /// ie. it is a real edge of the graph. |
---|
697 | /// |
---|
698 | /// \warning A removed edge (using Snapshot) could become valid again |
---|
699 | /// when new edges are added to the graph. |
---|
700 | bool valid(Edge e) const { return Parent::valid(e); } |
---|
701 | |
---|
702 | ///Clear the graph. |
---|
703 | |
---|
704 | ///Erase all the nodes and edges from the graph. |
---|
705 | /// |
---|
706 | void clear() { |
---|
707 | Parent::clear(); |
---|
708 | } |
---|
709 | |
---|
710 | public: |
---|
711 | |
---|
712 | class Snapshot; |
---|
713 | |
---|
714 | protected: |
---|
715 | |
---|
716 | void saveSnapshot(Snapshot &s) |
---|
717 | { |
---|
718 | s._graph = this; |
---|
719 | s.node_num = nodes.size(); |
---|
720 | s.arc_num = arcs.size(); |
---|
721 | } |
---|
722 | |
---|
723 | void restoreSnapshot(const Snapshot &s) |
---|
724 | { |
---|
725 | while(s.arc_num<arcs.size()) { |
---|
726 | int n=arcs.size()-1; |
---|
727 | Edge arc=edgeFromId(n/2); |
---|
728 | Parent::notifier(Edge()).erase(arc); |
---|
729 | std::vector<Arc> dir; |
---|
730 | dir.push_back(arcFromId(n)); |
---|
731 | dir.push_back(arcFromId(n-1)); |
---|
732 | Parent::notifier(Arc()).erase(dir); |
---|
733 | nodes[arcs[n].target].first_out=arcs[n].next_out; |
---|
734 | nodes[arcs[n-1].target].first_out=arcs[n-1].next_out; |
---|
735 | arcs.pop_back(); |
---|
736 | arcs.pop_back(); |
---|
737 | } |
---|
738 | while(s.node_num<nodes.size()) { |
---|
739 | int n=nodes.size()-1; |
---|
740 | Node node = nodeFromId(n); |
---|
741 | Parent::notifier(Node()).erase(node); |
---|
742 | nodes.pop_back(); |
---|
743 | } |
---|
744 | } |
---|
745 | |
---|
746 | public: |
---|
747 | |
---|
748 | ///Class to make a snapshot of the digraph and to restrore to it later. |
---|
749 | |
---|
750 | ///Class to make a snapshot of the digraph and to restrore to it later. |
---|
751 | /// |
---|
752 | ///The newly added nodes and arcs can be removed using the |
---|
753 | ///restore() function. |
---|
754 | /// |
---|
755 | ///\note After you restore a state, you cannot restore |
---|
756 | ///a later state, in other word you cannot add again the arcs deleted |
---|
757 | ///by restore() using another one Snapshot instance. |
---|
758 | /// |
---|
759 | ///\warning If you do not use correctly the snapshot that can cause |
---|
760 | ///either broken program, invalid state of the digraph, valid but |
---|
761 | ///not the restored digraph or no change. Because the runtime performance |
---|
762 | ///the validity of the snapshot is not stored. |
---|
763 | class Snapshot |
---|
764 | { |
---|
765 | SmartGraph *_graph; |
---|
766 | protected: |
---|
767 | friend class SmartGraph; |
---|
768 | unsigned int node_num; |
---|
769 | unsigned int arc_num; |
---|
770 | public: |
---|
771 | ///Default constructor. |
---|
772 | |
---|
773 | ///Default constructor. |
---|
774 | ///To actually make a snapshot you must call save(). |
---|
775 | /// |
---|
776 | Snapshot() : _graph(0) {} |
---|
777 | ///Constructor that immediately makes a snapshot |
---|
778 | |
---|
779 | ///This constructor immediately makes a snapshot of the digraph. |
---|
780 | ///\param graph The digraph we make a snapshot of. |
---|
781 | Snapshot(SmartGraph &graph) { |
---|
782 | graph.saveSnapshot(*this); |
---|
783 | } |
---|
784 | |
---|
785 | ///Make a snapshot. |
---|
786 | |
---|
787 | ///Make a snapshot of the graph. |
---|
788 | /// |
---|
789 | ///This function can be called more than once. In case of a repeated |
---|
790 | ///call, the previous snapshot gets lost. |
---|
791 | ///\param graph The digraph we make the snapshot of. |
---|
792 | void save(SmartGraph &graph) |
---|
793 | { |
---|
794 | graph.saveSnapshot(*this); |
---|
795 | } |
---|
796 | |
---|
797 | ///Undo the changes until a snapshot. |
---|
798 | |
---|
799 | ///Undo the changes until a snapshot created by save(). |
---|
800 | /// |
---|
801 | ///\note After you restored a state, you cannot restore |
---|
802 | ///a later state, in other word you cannot add again the arcs deleted |
---|
803 | ///by restore(). |
---|
804 | void restore() |
---|
805 | { |
---|
806 | _graph->restoreSnapshot(*this); |
---|
807 | } |
---|
808 | }; |
---|
809 | }; |
---|
810 | |
---|
811 | } //namespace lemon |
---|
812 | |
---|
813 | |
---|
814 | #endif //LEMON_SMART_GRAPH_H |
---|