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) 2003-2008 |
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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 | ///\ingroup paths |
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20 | ///\file |
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21 | ///\brief Classes for representing paths in graphs. |
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22 | /// |
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23 | |
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24 | #ifndef LEMON_PATH_UTILS_H |
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25 | #define LEMON_PATH_UTILS_H |
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26 | |
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27 | #include <lemon/concepts/path.h> |
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28 | #include <lemon/lemon_reader.h> |
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29 | #include <lemon/lemon_writer.h> |
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30 | |
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31 | namespace lemon { |
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32 | |
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33 | namespace _path_bits { |
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34 | |
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35 | template <typename Path, typename Enable = void> |
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36 | struct RevTagIndicator { |
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37 | static const bool value = false; |
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38 | }; |
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39 | |
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40 | template <typename Graph> |
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41 | struct RevTagIndicator< |
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42 | Graph, |
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43 | typename enable_if<typename Graph::RevTag, void>::type |
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44 | > { |
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45 | static const bool value = true; |
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46 | }; |
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47 | |
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48 | template <typename Target, typename Source, |
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49 | typename BuildEnable = void, typename RevEnable = void> |
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50 | struct PathCopySelector { |
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51 | static void copy(Target& target, const Source& source) { |
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52 | target.clear(); |
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53 | for (typename Source::EdgeIt it(source); it != INVALID; ++it) { |
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54 | target.addBack(it); |
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55 | } |
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56 | } |
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57 | }; |
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58 | |
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59 | template <typename Target, typename Source, typename BuildEnable> |
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60 | struct PathCopySelector< |
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61 | Target, Source, BuildEnable, |
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62 | typename enable_if<typename Source::RevPathTag, void>::type> { |
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63 | static void copy(Target& target, const Source& source) { |
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64 | target.clear(); |
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65 | for (typename Source::RevEdgeIt it(source); it != INVALID; ++it) { |
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66 | target.addFront(it); |
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67 | } |
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68 | } |
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69 | }; |
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70 | |
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71 | template <typename Target, typename Source, typename RevEnable> |
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72 | struct PathCopySelector< |
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73 | Target, Source, |
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74 | typename enable_if<typename Target::BuildTag, void>::type, RevEnable> { |
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75 | static void copy(Target& target, const Source& source) { |
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76 | target.clear(); |
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77 | target.build(source); |
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78 | } |
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79 | }; |
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80 | |
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81 | template <typename Target, typename Source> |
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82 | struct PathCopySelector< |
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83 | Target, Source, |
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84 | typename enable_if<typename Target::BuildTag, void>::type, |
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85 | typename enable_if<typename Source::RevPathTag, void>::type> { |
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86 | static void copy(Target& target, const Source& source) { |
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87 | target.clear(); |
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88 | target.buildRev(source); |
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89 | } |
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90 | }; |
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91 | |
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92 | } |
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93 | |
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94 | |
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95 | /// \brief Make of copy of a path. |
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96 | /// |
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97 | /// Make of copy of a path. |
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98 | template <typename Target, typename Source> |
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99 | void copyPath(Target& target, const Source& source) { |
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100 | checkConcept<concepts::PathDumper<typename Source::Graph>, Source>(); |
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101 | _path_bits::PathCopySelector<Target, Source>::copy(target, source); |
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102 | } |
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103 | |
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104 | /// \brief Checks the path's consistency. |
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105 | /// |
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106 | /// Checks that each edge's target is the next's source. |
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107 | /// |
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108 | template <typename Graph, typename Path> |
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109 | bool checkPath(const Graph& graph, const Path& path) { |
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110 | typename Path::EdgeIt it(path); |
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111 | if (it == INVALID) return true; |
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112 | typename Graph::Node node = graph.target(it); |
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113 | ++it; |
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114 | while (it != INVALID) { |
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115 | if (graph.source(it) != node) return false; |
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116 | node = graph.target(it); |
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117 | ++it; |
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118 | } |
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119 | return true; |
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120 | } |
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121 | |
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122 | /// \brief Gives back the source of the path |
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123 | /// |
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124 | /// Gives back the source of the path. |
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125 | template <typename Graph, typename Path> |
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126 | typename Graph::Node pathSource(const Graph& graph, const Path& path) { |
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127 | return graph.source(path.front()); |
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128 | } |
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129 | |
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130 | /// \brief Gives back the target of the path |
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131 | /// |
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132 | /// Gives back the target of the path. |
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133 | template <typename Graph, typename Path> |
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134 | typename Graph::Node pathTarget(const Graph& graph, const Path& path) { |
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135 | return graph.target(path.back()); |
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136 | } |
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137 | |
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138 | /// \brief Class which helps to iterate the nodes of a path |
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139 | /// |
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140 | /// In a sense, the path can be treated as a list of edges. The |
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141 | /// lemon path type stores just this list. As a consequence it |
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142 | /// cannot enumerate the nodes in the path and the zero length paths |
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143 | /// cannot store the node. |
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144 | /// |
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145 | /// This class implements the node iterator of a path structure. To |
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146 | /// provide this feature, the underlying graph should be given to |
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147 | /// the constructor of the iterator. |
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148 | template <typename Path> |
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149 | class PathNodeIt { |
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150 | private: |
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151 | const typename Path::Graph *_graph; |
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152 | typename Path::EdgeIt _it; |
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153 | typename Path::Graph::Node _nd; |
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154 | |
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155 | public: |
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156 | |
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157 | typedef typename Path::Graph Graph; |
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158 | typedef typename Graph::Node Node; |
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159 | |
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160 | /// Default constructor |
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161 | PathNodeIt() {} |
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162 | /// Invalid constructor |
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163 | PathNodeIt(Invalid) |
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164 | : _graph(0), _it(INVALID), _nd(INVALID) {} |
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165 | /// Constructor |
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166 | PathNodeIt(const Graph& graph, const Path& path) |
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167 | : _graph(&graph), _it(path) { |
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168 | _nd = (_it != INVALID ? _graph->source(_it) : INVALID); |
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169 | } |
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170 | /// Constructor |
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171 | PathNodeIt(const Graph& graph, const Path& path, const Node& src) |
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172 | : _graph(&graph), _it(path), _nd(src) {} |
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173 | |
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174 | ///Conversion to Graph::Node |
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175 | operator Node() const { |
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176 | return _nd; |
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177 | } |
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178 | |
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179 | /// Next node |
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180 | PathNodeIt& operator++() { |
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181 | if (_it == INVALID) _nd = INVALID; |
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182 | else { |
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183 | _nd = _graph->target(_it); |
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184 | ++_it; |
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185 | } |
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186 | return *this; |
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187 | } |
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188 | |
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189 | /// Comparison operator |
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190 | bool operator==(const PathNodeIt& n) const { |
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191 | return _it == n._it && _nd == n._nd; |
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192 | } |
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193 | /// Comparison operator |
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194 | bool operator!=(const PathNodeIt& n) const { |
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195 | return _it != n._it || _nd != n._nd; |
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196 | } |
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197 | /// Comparison operator |
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198 | bool operator<(const PathNodeIt& n) const { |
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199 | return (_it < n._it && _nd != INVALID); |
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200 | } |
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201 | |
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202 | }; |
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203 | |
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204 | /// \brief Item writer for paths |
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205 | /// |
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206 | /// This class can write paths into files. You can store paths in |
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207 | /// distinict mapset or in attributes section. |
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208 | /// |
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209 | ///\code |
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210 | /// GraphWriter<SmartGraph> gw(std::cout, g); |
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211 | /// NodeMapWriter<SmartGraph> nmw(gw, g, gw); |
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212 | /// |
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213 | /// SmartGraph::NodeMap<Path<SmartGraph> > pnm(g); |
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214 | /// for (SmartGraph::NodeIt n(g); n != INVALID; ++n) { |
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215 | /// pnm[n] = bfs.path(n); |
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216 | /// } |
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217 | /// nmw.writeNodeMap("pnm", pnm, PathWriter<Path<SmartGraph> >(gw)); |
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218 | /// |
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219 | /// gw.run(); |
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220 | ///\endcode |
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221 | /// |
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222 | /// \warning Do not use this class to write node or edge map values |
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223 | /// into usual nodesets or edgesets. You will not be able to read |
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224 | /// back your paths. Rather use NodeMapWriter, EdgeSetWriter or |
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225 | /// UEdgeSetWriter to dump paths from maps to lemon file. |
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226 | template <typename Path> |
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227 | class PathWriter { |
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228 | private: |
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229 | |
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230 | typedef typename Path::Edge Edge; |
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231 | std::auto_ptr<_writer_bits::LabelWriterBase<Edge> > edgeLabelWriter; |
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232 | |
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233 | public: |
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234 | |
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235 | typedef Path Value; |
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236 | |
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237 | PathWriter(const PathWriter& pw) { |
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238 | edgeLabelWriter.reset(pw.edgeLabelWriter->clone()); |
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239 | } |
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240 | |
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241 | /// \brief Constructor |
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242 | /// |
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243 | /// The paramter shold be an edge label writer which could |
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244 | /// be a GraphWriter or an EdgeSetWriter. |
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245 | template <typename EdgeLabelWriter> |
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246 | explicit PathWriter(const EdgeLabelWriter& _edgeLabelWriter) { |
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247 | edgeLabelWriter.reset(new _writer_bits:: |
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248 | LabelWriter<Edge, EdgeLabelWriter>(_edgeLabelWriter)); |
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249 | } |
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250 | |
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251 | /// \brief Writer function |
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252 | /// |
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253 | /// Writes the path to the current stream. The representation |
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254 | /// is the edge labels beetween parentheses. |
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255 | void write(std::ostream& os, const Value& value) const { |
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256 | if (!edgeLabelWriter->isLabelWriter()) { |
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257 | throw DataFormatError("Cannot find edgeset or label map"); |
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258 | } |
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259 | os << '(' << ' '; |
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260 | for (typename Path::EdgeIt e(value); e != INVALID; ++e) { |
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261 | edgeLabelWriter->write(os, e); |
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262 | os << ' '; |
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263 | } |
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264 | os << ')'; |
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265 | } |
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266 | |
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267 | }; |
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268 | |
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269 | namespace _path_bits { |
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270 | |
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271 | template <typename _Graph> |
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272 | class PathProxy { |
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273 | public: |
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274 | typedef False RevPathTag; |
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275 | |
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276 | typedef _Graph Graph; |
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277 | typedef typename Graph::Edge Edge; |
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278 | |
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279 | PathProxy(const std::vector<Edge>& edges) |
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280 | : _edges(edges) {} |
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281 | |
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282 | int length() const { |
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283 | return _edges.size(); |
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284 | } |
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285 | |
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286 | bool empty() const { |
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287 | return _edges.size() == 0; |
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288 | } |
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289 | |
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290 | class EdgeIt { |
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291 | public: |
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292 | EdgeIt() {} |
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293 | EdgeIt(const PathProxy& path) |
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294 | : _path(&path), _index(0) {} |
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295 | |
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296 | operator const Edge() const { |
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297 | return _path->_edges[_index]; |
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298 | } |
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299 | |
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300 | EdgeIt& operator++() { |
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301 | ++_index; |
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302 | return *this; |
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303 | } |
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304 | |
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305 | bool operator==(Invalid) const { |
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306 | return int(_path->_edges.size()) == _index; |
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307 | } |
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308 | bool operator!=(Invalid) const { |
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309 | return int(_path->_edges.size()) != _index; |
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310 | } |
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311 | |
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312 | private: |
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313 | const PathProxy* _path; |
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314 | int _index; |
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315 | }; |
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316 | |
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317 | private: |
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318 | const std::vector<Edge>& _edges; |
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319 | |
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320 | }; |
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321 | |
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322 | } |
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323 | |
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324 | /// \brief Item reader for paths |
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325 | /// |
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326 | /// This class can read paths from files. You can store paths in |
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327 | /// distinict mapset or in attributes section. |
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328 | /// |
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329 | ///\code |
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330 | /// GraphReader<SmartGraph> gr(std::cout, g); |
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331 | /// NodeMapReader<SmartGraph> nmr(gr, g, gr); |
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332 | /// |
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333 | /// SmartGraph::NodeMap<Path<SmartGraph> > pnm(g); |
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334 | /// nmr.readNodeMap("pnm", pnm, PathReader<Path<SmartGraph> >(gr)); |
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335 | /// |
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336 | /// gr.run(); |
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337 | ///\endcode |
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338 | /// |
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339 | /// \warning Do not use this class to read node or edge map values |
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340 | /// from nodesets or edgesets. The edges are not surely constructed |
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341 | /// when the edge list should be read. Rather use NodeMapReader, |
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342 | /// EdgeSetReader or UEdgeSetReader to read distinict map sets from file. |
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343 | template <typename Path> |
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344 | class PathReader { |
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345 | private: |
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346 | |
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347 | typedef typename Path::Edge Edge; |
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348 | std::auto_ptr<_reader_bits::LabelReaderBase<Edge> > edgeLabelReader; |
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349 | |
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350 | public: |
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351 | |
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352 | typedef Path Value; |
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353 | |
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354 | PathReader(const PathReader& pw) { |
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355 | edgeLabelReader.reset(pw.edgeLabelReader->clone()); |
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356 | } |
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357 | |
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358 | /// \brief Constructor |
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359 | /// |
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360 | /// The paramter shold be an edge label reader which could |
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361 | /// be a GraphReader or an EdgeSetReader. |
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362 | template <typename EdgeLabelReader> |
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363 | explicit PathReader(const EdgeLabelReader& _edgeLabelReader) { |
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364 | edgeLabelReader.reset(new _reader_bits:: |
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365 | LabelReader<Edge, EdgeLabelReader>(_edgeLabelReader)); |
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366 | } |
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367 | |
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368 | |
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369 | /// \brief Reader function |
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370 | /// |
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371 | /// Reads the path from the current stream. The representation |
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372 | /// is the edge labels beetween parentheses. |
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373 | void read(std::istream& is, Value& value) const { |
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374 | if (!edgeLabelReader->isLabelReader()) { |
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375 | throw DataFormatError("Cannot find edgeset or label map"); |
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376 | } |
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377 | char c; |
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378 | if (!(is >> c) || c != '(') |
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379 | throw DataFormatError("PathReader format error"); |
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380 | std::vector<typename Path::Edge> v; |
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381 | while (is >> c && c != ')') { |
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382 | is.putback(c); |
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383 | Edge edge = edgeLabelReader->read(is); |
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384 | v.push_back(edge); |
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385 | } |
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386 | if (!is) throw DataFormatError("PathReader format error"); |
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387 | copyPath(value, _path_bits::PathProxy<typename Path::Edge>(v)); |
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388 | } |
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389 | |
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390 | }; |
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391 | |
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392 | } |
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393 | |
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394 | #endif |
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