1 | /* -*- C++ -*- |
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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) 2003-2006 |
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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_LIST_GRAPH_H |
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20 | #define LEMON_LIST_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 ListGraph, ListUGraph classes. |
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25 | |
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26 | #include <lemon/bits/erasable_graph_extender.h> |
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27 | #include <lemon/bits/clearable_graph_extender.h> |
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28 | #include <lemon/bits/extendable_graph_extender.h> |
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29 | #include <lemon/bits/iterable_graph_extender.h> |
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30 | #include <lemon/bits/alteration_notifier.h> |
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31 | #include <lemon/bits/default_map.h> |
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32 | #include <lemon/bits/graph_extender.h> |
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33 | |
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34 | #include <lemon/error.h> |
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35 | |
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36 | #include <list> |
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37 | |
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38 | namespace lemon { |
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39 | |
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40 | class ListGraphBase { |
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41 | |
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42 | protected: |
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43 | struct NodeT { |
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44 | int first_in, first_out; |
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45 | int prev, next; |
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46 | }; |
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47 | |
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48 | struct EdgeT { |
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49 | int target, source; |
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50 | int prev_in, prev_out; |
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51 | int next_in, next_out; |
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52 | }; |
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53 | |
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54 | std::vector<NodeT> nodes; |
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55 | |
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56 | int first_node; |
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57 | |
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58 | int first_free_node; |
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59 | |
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60 | std::vector<EdgeT> edges; |
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61 | |
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62 | int first_free_edge; |
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63 | |
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64 | public: |
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65 | |
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66 | typedef ListGraphBase Graph; |
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67 | |
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68 | class Node { |
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69 | friend class ListGraphBase; |
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70 | protected: |
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71 | |
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72 | int id; |
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73 | Node(int pid) { id = pid;} |
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74 | |
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75 | public: |
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76 | Node() {} |
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77 | Node (Invalid) { id = -1; } |
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78 | bool operator==(const Node& node) const {return id == node.id;} |
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79 | bool operator!=(const Node& node) const {return id != node.id;} |
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80 | bool operator<(const Node& node) const {return id < node.id;} |
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81 | }; |
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82 | |
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83 | class Edge { |
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84 | friend class ListGraphBase; |
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85 | protected: |
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86 | |
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87 | int id; |
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88 | Edge(int pid) { id = pid;} |
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89 | |
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90 | public: |
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91 | Edge() {} |
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92 | Edge (Invalid) { id = -1; } |
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93 | bool operator==(const Edge& edge) const {return id == edge.id;} |
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94 | bool operator!=(const Edge& edge) const {return id != edge.id;} |
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95 | bool operator<(const Edge& edge) const {return id < edge.id;} |
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96 | }; |
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97 | |
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98 | |
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99 | |
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100 | ListGraphBase() |
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101 | : nodes(), first_node(-1), |
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102 | first_free_node(-1), edges(), first_free_edge(-1) {} |
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103 | |
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104 | |
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105 | /// Maximum node ID. |
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106 | |
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107 | /// Maximum node ID. |
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108 | ///\sa id(Node) |
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109 | int maxNodeId() const { return nodes.size()-1; } |
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110 | |
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111 | /// Maximum edge ID. |
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112 | |
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113 | /// Maximum edge ID. |
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114 | ///\sa id(Edge) |
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115 | int maxEdgeId() const { return edges.size()-1; } |
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116 | |
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117 | Node source(Edge e) const { return edges[e.id].source; } |
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118 | Node target(Edge e) const { return edges[e.id].target; } |
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119 | |
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120 | |
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121 | void first(Node& node) const { |
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122 | node.id = first_node; |
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123 | } |
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124 | |
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125 | void next(Node& node) const { |
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126 | node.id = nodes[node.id].next; |
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127 | } |
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128 | |
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129 | |
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130 | void first(Edge& e) const { |
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131 | int n; |
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132 | for(n = first_node; |
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133 | n!=-1 && nodes[n].first_in == -1; |
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134 | n = nodes[n].next); |
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135 | e.id = (n == -1) ? -1 : nodes[n].first_in; |
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136 | } |
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137 | |
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138 | void next(Edge& edge) const { |
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139 | if (edges[edge.id].next_in != -1) { |
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140 | edge.id = edges[edge.id].next_in; |
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141 | } else { |
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142 | int n; |
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143 | for(n = nodes[edges[edge.id].target].next; |
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144 | n!=-1 && nodes[n].first_in == -1; |
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145 | n = nodes[n].next); |
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146 | edge.id = (n == -1) ? -1 : nodes[n].first_in; |
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147 | } |
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148 | } |
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149 | |
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150 | void firstOut(Edge &e, const Node& v) const { |
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151 | e.id = nodes[v.id].first_out; |
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152 | } |
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153 | void nextOut(Edge &e) const { |
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154 | e.id=edges[e.id].next_out; |
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155 | } |
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156 | |
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157 | void firstIn(Edge &e, const Node& v) const { |
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158 | e.id = nodes[v.id].first_in; |
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159 | } |
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160 | void nextIn(Edge &e) const { |
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161 | e.id=edges[e.id].next_in; |
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162 | } |
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163 | |
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164 | |
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165 | static int id(Node v) { return v.id; } |
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166 | static int id(Edge e) { return e.id; } |
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167 | |
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168 | static Node nodeFromId(int id) { return Node(id);} |
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169 | static Edge edgeFromId(int id) { return Edge(id);} |
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170 | |
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171 | /// Adds a new node to the graph. |
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172 | |
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173 | /// \warning It adds the new node to the front of the list. |
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174 | /// (i.e. the lastly added node becomes the first.) |
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175 | Node addNode() { |
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176 | int n; |
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177 | |
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178 | if(first_free_node==-1) { |
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179 | n = nodes.size(); |
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180 | nodes.push_back(NodeT()); |
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181 | } else { |
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182 | n = first_free_node; |
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183 | first_free_node = nodes[n].next; |
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184 | } |
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185 | |
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186 | nodes[n].next = first_node; |
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187 | if(first_node != -1) nodes[first_node].prev = n; |
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188 | first_node = n; |
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189 | nodes[n].prev = -1; |
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190 | |
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191 | nodes[n].first_in = nodes[n].first_out = -1; |
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192 | |
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193 | return Node(n); |
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194 | } |
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195 | |
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196 | Edge addEdge(Node u, Node v) { |
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197 | int n; |
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198 | |
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199 | if (first_free_edge == -1) { |
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200 | n = edges.size(); |
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201 | edges.push_back(EdgeT()); |
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202 | } else { |
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203 | n = first_free_edge; |
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204 | first_free_edge = edges[n].next_in; |
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205 | } |
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206 | |
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207 | edges[n].source = u.id; |
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208 | edges[n].target = v.id; |
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209 | |
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210 | edges[n].next_out = nodes[u.id].first_out; |
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211 | if(nodes[u.id].first_out != -1) { |
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212 | edges[nodes[u.id].first_out].prev_out = n; |
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213 | } |
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214 | |
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215 | edges[n].next_in = nodes[v.id].first_in; |
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216 | if(nodes[v.id].first_in != -1) { |
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217 | edges[nodes[v.id].first_in].prev_in = n; |
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218 | } |
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219 | |
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220 | edges[n].prev_in = edges[n].prev_out = -1; |
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221 | |
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222 | nodes[u.id].first_out = nodes[v.id].first_in = n; |
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223 | |
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224 | return Edge(n); |
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225 | } |
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226 | |
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227 | void erase(const Node& node) { |
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228 | int n = node.id; |
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229 | |
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230 | if(nodes[n].next != -1) { |
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231 | nodes[nodes[n].next].prev = nodes[n].prev; |
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232 | } |
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233 | |
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234 | if(nodes[n].prev != -1) { |
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235 | nodes[nodes[n].prev].next = nodes[n].next; |
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236 | } else { |
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237 | first_node = nodes[n].next; |
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238 | } |
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239 | |
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240 | nodes[n].next = first_free_node; |
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241 | first_free_node = n; |
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242 | |
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243 | } |
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244 | |
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245 | void erase(const Edge& edge) { |
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246 | int n = edge.id; |
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247 | |
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248 | if(edges[n].next_in!=-1) { |
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249 | edges[edges[n].next_in].prev_in = edges[n].prev_in; |
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250 | } |
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251 | |
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252 | if(edges[n].prev_in!=-1) { |
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253 | edges[edges[n].prev_in].next_in = edges[n].next_in; |
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254 | } else { |
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255 | nodes[edges[n].target].first_in = edges[n].next_in; |
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256 | } |
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257 | |
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258 | |
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259 | if(edges[n].next_out!=-1) { |
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260 | edges[edges[n].next_out].prev_out = edges[n].prev_out; |
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261 | } |
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262 | |
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263 | if(edges[n].prev_out!=-1) { |
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264 | edges[edges[n].prev_out].next_out = edges[n].next_out; |
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265 | } else { |
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266 | nodes[edges[n].source].first_out = edges[n].next_out; |
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267 | } |
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268 | |
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269 | edges[n].next_in = first_free_edge; |
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270 | first_free_edge = n; |
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271 | |
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272 | } |
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273 | |
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274 | void clear() { |
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275 | edges.clear(); |
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276 | nodes.clear(); |
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277 | first_node = first_free_node = first_free_edge = -1; |
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278 | } |
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279 | |
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280 | protected: |
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281 | void _changeTarget(Edge e, Node n) |
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282 | { |
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283 | if(edges[e.id].next_in != -1) |
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284 | edges[edges[e.id].next_in].prev_in = edges[e.id].prev_in; |
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285 | if(edges[e.id].prev_in != -1) |
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286 | edges[edges[e.id].prev_in].next_in = edges[e.id].next_in; |
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287 | else nodes[edges[e.id].target].first_in = edges[e.id].next_in; |
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288 | if (nodes[n.id].first_in != -1) { |
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289 | edges[nodes[n.id].first_in].prev_in = e.id; |
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290 | } |
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291 | edges[e.id].target = n.id; |
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292 | edges[e.id].prev_in = -1; |
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293 | edges[e.id].next_in = nodes[n.id].first_in; |
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294 | nodes[n.id].first_in = e.id; |
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295 | } |
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296 | void _changeSource(Edge e, Node n) |
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297 | { |
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298 | if(edges[e.id].next_out != -1) |
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299 | edges[edges[e.id].next_out].prev_out = edges[e.id].prev_out; |
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300 | if(edges[e.id].prev_out != -1) |
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301 | edges[edges[e.id].prev_out].next_out = edges[e.id].next_out; |
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302 | else nodes[edges[e.id].source].first_out = edges[e.id].next_out; |
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303 | if (nodes[n.id].first_out != -1) { |
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304 | edges[nodes[n.id].first_out].prev_out = e.id; |
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305 | } |
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306 | edges[e.id].source = n.id; |
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307 | edges[e.id].prev_out = -1; |
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308 | edges[e.id].next_out = nodes[n.id].first_out; |
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309 | nodes[n.id].first_out = e.id; |
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310 | } |
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311 | |
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312 | }; |
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313 | |
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314 | typedef ErasableGraphExtender< |
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315 | ClearableGraphExtender< |
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316 | ExtendableGraphExtender< |
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317 | MappableGraphExtender< |
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318 | IterableGraphExtender< |
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319 | AlterableGraphExtender< |
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320 | GraphExtender<ListGraphBase> > > > > > > ExtendedListGraphBase; |
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321 | |
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322 | /// \addtogroup graphs |
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323 | /// @{ |
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324 | |
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325 | ///A list graph class. |
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326 | |
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327 | ///This is a simple and fast erasable graph implementation. |
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328 | /// |
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329 | ///It addition that it conforms to the |
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330 | ///\ref concept::ErasableGraph "ErasableGraph" concept, |
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331 | ///it also provides several additional useful extra functionalities. |
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332 | ///\sa concept::ErasableGraph. |
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333 | |
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334 | class ListGraph : public ExtendedListGraphBase |
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335 | { |
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336 | public: |
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337 | /// Changes the target of \c e to \c n |
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338 | |
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339 | /// Changes the target of \c e to \c n |
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340 | /// |
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341 | ///\note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s |
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342 | ///referencing the changed edge remain |
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343 | ///valid. However <tt>InEdge</tt>'s are invalidated. |
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344 | void changeTarget(Edge e, Node n) { |
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345 | _changeTarget(e,n); |
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346 | } |
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347 | /// Changes the source of \c e to \c n |
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348 | |
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349 | /// Changes the source of \c e to \c n |
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350 | /// |
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351 | ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s |
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352 | ///referencing the changed edge remain |
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353 | ///valid. However <tt>OutEdge</tt>'s are invalidated. |
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354 | void changeSource(Edge e, Node n) { |
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355 | _changeSource(e,n); |
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356 | } |
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357 | |
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358 | /// Invert the direction of an edge. |
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359 | |
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360 | ///\note The <tt>Edge</tt>'s |
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361 | ///referencing the changed edge remain |
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362 | ///valid. However <tt>OutEdge</tt>'s and <tt>InEdge</tt>'s are invalidated. |
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363 | void reverseEdge(Edge e) { |
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364 | Node t=target(e); |
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365 | _changeTarget(e,source(e)); |
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366 | _changeSource(e,t); |
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367 | } |
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368 | |
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369 | ///Using this it possible to avoid the superfluous memory allocation. |
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370 | |
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371 | ///Using this it possible to avoid the superfluous memory allocation. |
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372 | ///\todo more docs... |
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373 | void reserveEdge(int n) { edges.reserve(n); }; |
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374 | |
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375 | ///Contract two nodes. |
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376 | |
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377 | ///This function contracts two nodes. |
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378 | /// |
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379 | ///Node \p b will be removed but instead of deleting |
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380 | ///its neighboring edges, they will be joined to \p a. |
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381 | ///The last parameter \p r controls whether to remove loops. \c true |
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382 | ///means that loops will be removed. |
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383 | /// |
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384 | ///\note The <tt>Edge</tt>s |
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385 | ///referencing a moved edge remain |
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386 | ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s |
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387 | ///may be invalidated. |
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388 | void contract(Node a, Node b, bool r = true) |
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389 | { |
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390 | for(OutEdgeIt e(*this,b);e!=INVALID;) { |
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391 | OutEdgeIt f=e; |
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392 | ++f; |
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393 | if(r && target(e)==a) erase(e); |
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394 | else changeSource(e,a); |
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395 | e=f; |
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396 | } |
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397 | for(InEdgeIt e(*this,b);e!=INVALID;) { |
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398 | InEdgeIt f=e; |
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399 | ++f; |
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400 | if(r && source(e)==a) erase(e); |
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401 | else changeTarget(e,a); |
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402 | e=f; |
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403 | } |
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404 | erase(b); |
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405 | } |
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406 | |
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407 | ///Split a node. |
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408 | |
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409 | ///This function splits a node. First a new node is added to the graph, |
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410 | ///then the source of each outgoing edge of \c n is moved to this new node. |
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411 | ///If \c connect is \c true (this is the default value), then a new edge |
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412 | ///from \c n to the newly created node is also added. |
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413 | ///\return The newly created node. |
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414 | /// |
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415 | ///\note The <tt>Edge</tt>s |
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416 | ///referencing a moved edge remain |
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417 | ///valid. However <tt>InEdge</tt>'s and <tt>OutEdge</tt>'s |
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418 | ///may be invalidated. |
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419 | ///\warning This functionality cannot be used together with the Snapshot |
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420 | ///feature. |
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421 | ///\todo It could be implemented in a bit faster way. |
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422 | Node split(Node n, bool connect = true) |
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423 | { |
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424 | Node b = addNode(); |
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425 | for(OutEdgeIt e(*this,n);e!=INVALID;) { |
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426 | OutEdgeIt f=e; |
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427 | ++f; |
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428 | changeSource(e,b); |
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429 | e=f; |
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430 | } |
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431 | if(connect) addEdge(n,b); |
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432 | return b; |
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433 | } |
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434 | |
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435 | ///Split an edge. |
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436 | |
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437 | ///This function splits an edge. First a new node \c b is added to the graph, |
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438 | ///then the original edge is re-targetes to \c b. Finally an edge |
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439 | ///from \c b to the original target is added. |
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440 | ///\return The newly created node. |
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441 | ///\warning This functionality cannot be used together with the Snapshot |
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442 | ///feature. |
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443 | Node split(Edge e) |
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444 | { |
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445 | Node b = addNode(); |
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446 | addEdge(b,target(e)); |
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447 | changeTarget(e,b); |
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448 | return b; |
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449 | } |
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450 | |
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451 | ///Class to make a snapshot of the graph and to restrore to it later. |
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452 | |
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453 | ///Class to make a snapshot of the graph and to restrore to it later. |
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454 | /// |
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455 | ///The newly added nodes and edges can be removed using the |
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456 | ///restore() function. |
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457 | /// |
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458 | ///\warning Edge and node deletions cannot be restored. |
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459 | ///\warning Snapshots cannot be nested. |
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460 | class Snapshot : protected AlterationNotifier<Node>::ObserverBase, |
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461 | protected AlterationNotifier<Edge>::ObserverBase |
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462 | { |
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463 | public: |
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464 | |
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465 | class UnsupportedOperation : public LogicError { |
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466 | public: |
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467 | virtual const char* exceptionName() const { |
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468 | return "lemon::ListGraph::Snapshot::UnsupportedOperation"; |
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469 | } |
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470 | }; |
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471 | |
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472 | |
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473 | protected: |
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474 | |
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475 | ListGraph *g; |
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476 | std::list<Node> added_nodes; |
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477 | std::list<Edge> added_edges; |
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478 | |
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479 | bool active; |
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480 | virtual void add(const Node& n) { |
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481 | added_nodes.push_back(n); |
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482 | }; |
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483 | virtual void erase(const Node&) |
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484 | { |
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485 | throw UnsupportedOperation(); |
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486 | } |
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487 | virtual void add(const Edge& n) { |
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488 | added_edges.push_back(n); |
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489 | }; |
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490 | virtual void erase(const Edge&) |
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491 | { |
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492 | throw UnsupportedOperation(); |
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493 | } |
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494 | |
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495 | ///\bug What is this used for? |
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496 | /// |
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497 | virtual void build() {} |
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498 | ///\bug What is this used for? |
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499 | /// |
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500 | virtual void clear() {} |
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501 | |
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502 | void regist(ListGraph &_g) { |
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503 | g=&_g; |
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504 | AlterationNotifier<Node>::ObserverBase:: |
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505 | attach(g->getNotifier(Node())); |
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506 | AlterationNotifier<Edge>::ObserverBase:: |
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507 | attach(g->getNotifier(Edge())); |
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508 | } |
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509 | |
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510 | void deregist() { |
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511 | AlterationNotifier<Node>::ObserverBase:: |
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512 | detach(); |
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513 | AlterationNotifier<Edge>::ObserverBase:: |
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514 | detach(); |
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515 | g=0; |
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516 | } |
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517 | |
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518 | public: |
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519 | ///Default constructur. |
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520 | |
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521 | ///Default constructur. |
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522 | ///To actually make a snapshot you must call save(). |
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523 | /// |
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524 | Snapshot() : g(0) {} |
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525 | ///Constructor that immediately makes a snapshot. |
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526 | |
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527 | ///This constructor immediately makes a snapshot of the graph. |
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528 | ///\param _g The graph we make a snapshot of. |
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529 | Snapshot(ListGraph &_g) { |
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530 | regist(_g); |
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531 | } |
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532 | ///\bug Is it necessary? |
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533 | /// |
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534 | ~Snapshot() |
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535 | { |
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536 | if(g) deregist(); |
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537 | } |
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538 | |
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539 | ///Make a snapshot. |
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540 | |
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541 | ///Make a snapshot of the graph. |
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542 | /// |
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543 | ///This function can be called more than once. In case of a repeated |
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544 | ///call, the previous snapshot gets lost. |
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545 | ///\param _g The graph we make the snapshot of. |
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546 | void save(ListGraph &_g) |
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547 | { |
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548 | if(g!=&_g) { |
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549 | if(g) deregist(); |
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550 | regist(_g); |
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551 | } |
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552 | added_nodes.clear(); |
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553 | added_edges.clear(); |
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554 | } |
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555 | |
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556 | ///Undo the changes until the last snapshot. |
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557 | |
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558 | ///Undo the changes until last snapshot created by save(). |
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559 | /// |
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560 | ///\todo This function might be called undo(). |
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561 | void restore() { |
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562 | ListGraph &old_g=*g; |
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563 | deregist(); |
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564 | while(!added_edges.empty()) { |
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565 | old_g.erase(added_edges.front()); |
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566 | added_edges.pop_front(); |
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567 | } |
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568 | while(!added_nodes.empty()) { |
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569 | old_g.erase(added_nodes.front()); |
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570 | added_nodes.pop_front(); |
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571 | } |
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572 | } |
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573 | }; |
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574 | |
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575 | }; |
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576 | |
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577 | ///@} |
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578 | |
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579 | /**************** Undirected List Graph ****************/ |
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580 | |
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581 | typedef ErasableUGraphExtender< |
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582 | ClearableUGraphExtender< |
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583 | ExtendableUGraphExtender< |
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584 | MappableUGraphExtender< |
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585 | IterableUGraphExtender< |
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586 | AlterableUGraphExtender< |
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587 | UGraphExtender<ListGraphBase> > > > > > > ExtendedListUGraphBase; |
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588 | |
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589 | /// \addtogroup graphs |
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590 | /// @{ |
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591 | |
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592 | ///An undirected list graph class. |
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593 | |
---|
594 | ///This is a simple and fast erasable undirected graph implementation. |
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595 | /// |
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596 | ///It conforms to the |
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597 | ///\ref concept::UGraph "UGraph" concept. |
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598 | /// |
---|
599 | ///\sa concept::UGraph. |
---|
600 | /// |
---|
601 | ///\todo Snapshot, reverseEdge(), changeTarget(), changeSource(), contract() |
---|
602 | ///haven't been implemented yet. |
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603 | /// |
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604 | class ListUGraph : public ExtendedListUGraphBase { |
---|
605 | public: |
---|
606 | typedef ExtendedListUGraphBase Parent; |
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607 | /// \brief Changes the target of \c e to \c n |
---|
608 | /// |
---|
609 | /// Changes the target of \c e to \c n |
---|
610 | /// |
---|
611 | /// \note The <tt>Edge</tt>'s and <tt>OutEdge</tt>'s |
---|
612 | /// referencing the changed edge remain |
---|
613 | /// valid. However <tt>InEdge</tt>'s are invalidated. |
---|
614 | void changeTarget(UEdge e, Node n) { |
---|
615 | _changeTarget(e,n); |
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616 | } |
---|
617 | /// Changes the source of \c e to \c n |
---|
618 | /// |
---|
619 | /// Changes the source of \c e to \c n |
---|
620 | /// |
---|
621 | ///\note The <tt>Edge</tt>'s and <tt>InEdge</tt>'s |
---|
622 | ///referencing the changed edge remain |
---|
623 | ///valid. However <tt>OutEdge</tt>'s are invalidated. |
---|
624 | void changeSource(UEdge e, Node n) { |
---|
625 | _changeSource(e,n); |
---|
626 | } |
---|
627 | /// \brief Contract two nodes. |
---|
628 | /// |
---|
629 | /// This function contracts two nodes. |
---|
630 | /// |
---|
631 | /// Node \p b will be removed but instead of deleting |
---|
632 | /// its neighboring edges, they will be joined to \p a. |
---|
633 | /// The last parameter \p r controls whether to remove loops. \c true |
---|
634 | /// means that loops will be removed. |
---|
635 | /// |
---|
636 | /// \note The <tt>Edge</tt>s |
---|
637 | /// referencing a moved edge remain |
---|
638 | /// valid. |
---|
639 | void contract(Node a, Node b, bool r = true) { |
---|
640 | for(IncEdgeIt e(*this, b); e!=INVALID;) { |
---|
641 | IncEdgeIt f = e; ++f; |
---|
642 | if (r && runningNode(e) == a) { |
---|
643 | erase(e); |
---|
644 | } else if (source(e) == b) { |
---|
645 | changeSource(e, a); |
---|
646 | } else { |
---|
647 | changeTarget(e, a); |
---|
648 | } |
---|
649 | e = f; |
---|
650 | } |
---|
651 | erase(b); |
---|
652 | } |
---|
653 | }; |
---|
654 | |
---|
655 | |
---|
656 | /// @} |
---|
657 | } //namespace lemon |
---|
658 | |
---|
659 | |
---|
660 | #endif |
---|