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) 2003-2009 |
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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_DIJKSTRA_H |
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20 | #define LEMON_DIJKSTRA_H |
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21 | |
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22 | ///\ingroup shortest_path |
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23 | ///\file |
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24 | ///\brief Dijkstra algorithm. |
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25 | |
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26 | #include <limits> |
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27 | #include <lemon/list_graph.h> |
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28 | #include <lemon/bin_heap.h> |
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29 | #include <lemon/bits/path_dump.h> |
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30 | #include <lemon/core.h> |
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31 | #include <lemon/error.h> |
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32 | #include <lemon/maps.h> |
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33 | #include <lemon/path.h> |
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34 | |
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35 | namespace lemon { |
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36 | |
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37 | /// \brief Default operation traits for the Dijkstra algorithm class. |
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38 | /// |
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39 | /// This operation traits class defines all computational operations and |
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40 | /// constants which are used in the Dijkstra algorithm. |
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41 | template <typename V> |
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42 | struct DijkstraDefaultOperationTraits { |
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43 | /// \e |
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44 | typedef V Value; |
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45 | /// \brief Gives back the zero value of the type. |
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46 | static Value zero() { |
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47 | return static_cast<Value>(0); |
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48 | } |
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49 | /// \brief Gives back the sum of the given two elements. |
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50 | static Value plus(const Value& left, const Value& right) { |
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51 | return left + right; |
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52 | } |
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53 | /// \brief Gives back true only if the first value is less than the second. |
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54 | static bool less(const Value& left, const Value& right) { |
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55 | return left < right; |
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56 | } |
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57 | }; |
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58 | |
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59 | ///Default traits class of Dijkstra class. |
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60 | |
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61 | ///Default traits class of Dijkstra class. |
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62 | ///\tparam GR The type of the digraph. |
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63 | ///\tparam LEN The type of the length map. |
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64 | template<typename GR, typename LEN> |
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65 | struct DijkstraDefaultTraits |
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66 | { |
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67 | ///The type of the digraph the algorithm runs on. |
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68 | typedef GR Digraph; |
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69 | |
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70 | ///The type of the map that stores the arc lengths. |
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71 | |
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72 | ///The type of the map that stores the arc lengths. |
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73 | ///It must meet the \ref concepts::ReadMap "ReadMap" concept. |
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74 | typedef LEN LengthMap; |
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75 | ///The type of the length of the arcs. |
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76 | typedef typename LEN::Value Value; |
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77 | |
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78 | /// Operation traits for %Dijkstra algorithm. |
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79 | |
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80 | /// This class defines the operations that are used in the algorithm. |
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81 | /// \see DijkstraDefaultOperationTraits |
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82 | typedef DijkstraDefaultOperationTraits<Value> OperationTraits; |
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83 | |
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84 | /// The cross reference type used by the heap. |
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85 | |
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86 | /// The cross reference type used by the heap. |
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87 | /// Usually it is \c Digraph::NodeMap<int>. |
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88 | typedef typename Digraph::template NodeMap<int> HeapCrossRef; |
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89 | ///Instantiates a \c HeapCrossRef. |
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90 | |
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91 | ///This function instantiates a \ref HeapCrossRef. |
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92 | /// \param g is the digraph, to which we would like to define the |
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93 | /// \ref HeapCrossRef. |
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94 | static HeapCrossRef *createHeapCrossRef(const Digraph &g) |
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95 | { |
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96 | return new HeapCrossRef(g); |
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97 | } |
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98 | |
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99 | ///The heap type used by the %Dijkstra algorithm. |
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100 | |
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101 | ///The heap type used by the Dijkstra algorithm. |
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102 | /// |
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103 | ///\sa BinHeap |
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104 | ///\sa Dijkstra |
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105 | typedef BinHeap<typename LEN::Value, HeapCrossRef, std::less<Value> > Heap; |
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106 | ///Instantiates a \c Heap. |
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107 | |
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108 | ///This function instantiates a \ref Heap. |
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109 | static Heap *createHeap(HeapCrossRef& r) |
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110 | { |
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111 | return new Heap(r); |
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112 | } |
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113 | |
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114 | ///\brief The type of the map that stores the predecessor |
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115 | ///arcs of the shortest paths. |
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116 | /// |
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117 | ///The type of the map that stores the predecessor |
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118 | ///arcs of the shortest paths. |
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119 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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120 | typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
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121 | ///Instantiates a \c PredMap. |
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122 | |
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123 | ///This function instantiates a \ref PredMap. |
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124 | ///\param g is the digraph, to which we would like to define the |
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125 | ///\ref PredMap. |
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126 | static PredMap *createPredMap(const Digraph &g) |
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127 | { |
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128 | return new PredMap(g); |
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129 | } |
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130 | |
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131 | ///The type of the map that indicates which nodes are processed. |
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132 | |
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133 | ///The type of the map that indicates which nodes are processed. |
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134 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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135 | ///By default it is a NullMap. |
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136 | typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
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137 | ///Instantiates a \c ProcessedMap. |
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138 | |
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139 | ///This function instantiates a \ref ProcessedMap. |
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140 | ///\param g is the digraph, to which |
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141 | ///we would like to define the \ref ProcessedMap. |
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142 | #ifdef DOXYGEN |
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143 | static ProcessedMap *createProcessedMap(const Digraph &g) |
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144 | #else |
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145 | static ProcessedMap *createProcessedMap(const Digraph &) |
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146 | #endif |
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147 | { |
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148 | return new ProcessedMap(); |
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149 | } |
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150 | |
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151 | ///The type of the map that stores the distances of the nodes. |
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152 | |
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153 | ///The type of the map that stores the distances of the nodes. |
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154 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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155 | typedef typename Digraph::template NodeMap<typename LEN::Value> DistMap; |
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156 | ///Instantiates a \c DistMap. |
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157 | |
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158 | ///This function instantiates a \ref DistMap. |
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159 | ///\param g is the digraph, to which we would like to define |
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160 | ///the \ref DistMap. |
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161 | static DistMap *createDistMap(const Digraph &g) |
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162 | { |
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163 | return new DistMap(g); |
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164 | } |
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165 | }; |
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166 | |
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167 | ///%Dijkstra algorithm class. |
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168 | |
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169 | /// \ingroup shortest_path |
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170 | ///This class provides an efficient implementation of the %Dijkstra algorithm. |
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171 | /// |
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172 | ///The arc lengths are passed to the algorithm using a |
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173 | ///\ref concepts::ReadMap "ReadMap", |
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174 | ///so it is easy to change it to any kind of length. |
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175 | ///The type of the length is determined by the |
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176 | ///\ref concepts::ReadMap::Value "Value" of the length map. |
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177 | ///It is also possible to change the underlying priority heap. |
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178 | /// |
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179 | ///There is also a \ref dijkstra() "function-type interface" for the |
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180 | ///%Dijkstra algorithm, which is convenient in the simplier cases and |
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181 | ///it can be used easier. |
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182 | /// |
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183 | ///\tparam GR The type of the digraph the algorithm runs on. |
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184 | ///The default type is \ref ListDigraph. |
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185 | ///\tparam LEN A \ref concepts::ReadMap "readable" arc map that specifies |
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186 | ///the lengths of the arcs. |
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187 | ///It is read once for each arc, so the map may involve in |
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188 | ///relatively time consuming process to compute the arc lengths if |
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189 | ///it is necessary. The default map type is \ref |
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190 | ///concepts::Digraph::ArcMap "GR::ArcMap<int>". |
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191 | #ifdef DOXYGEN |
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192 | template <typename GR, typename LEN, typename TR> |
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193 | #else |
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194 | template <typename GR=ListDigraph, |
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195 | typename LEN=typename GR::template ArcMap<int>, |
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196 | typename TR=DijkstraDefaultTraits<GR,LEN> > |
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197 | #endif |
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198 | class Dijkstra { |
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199 | public: |
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200 | |
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201 | ///The type of the digraph the algorithm runs on. |
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202 | typedef typename TR::Digraph Digraph; |
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203 | |
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204 | ///The type of the length of the arcs. |
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205 | typedef typename TR::LengthMap::Value Value; |
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206 | ///The type of the map that stores the arc lengths. |
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207 | typedef typename TR::LengthMap LengthMap; |
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208 | ///\brief The type of the map that stores the predecessor arcs of the |
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209 | ///shortest paths. |
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210 | typedef typename TR::PredMap PredMap; |
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211 | ///The type of the map that stores the distances of the nodes. |
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212 | typedef typename TR::DistMap DistMap; |
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213 | ///The type of the map that indicates which nodes are processed. |
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214 | typedef typename TR::ProcessedMap ProcessedMap; |
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215 | ///The type of the paths. |
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216 | typedef PredMapPath<Digraph, PredMap> Path; |
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217 | ///The cross reference type used for the current heap. |
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218 | typedef typename TR::HeapCrossRef HeapCrossRef; |
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219 | ///The heap type used by the algorithm. |
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220 | typedef typename TR::Heap Heap; |
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221 | ///\brief The \ref DijkstraDefaultOperationTraits "operation traits class" |
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222 | ///of the algorithm. |
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223 | typedef typename TR::OperationTraits OperationTraits; |
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224 | |
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225 | ///The \ref DijkstraDefaultTraits "traits class" of the algorithm. |
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226 | typedef TR Traits; |
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227 | |
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228 | private: |
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229 | |
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230 | typedef typename Digraph::Node Node; |
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231 | typedef typename Digraph::NodeIt NodeIt; |
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232 | typedef typename Digraph::Arc Arc; |
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233 | typedef typename Digraph::OutArcIt OutArcIt; |
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234 | |
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235 | //Pointer to the underlying digraph. |
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236 | const Digraph *G; |
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237 | //Pointer to the length map. |
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238 | const LengthMap *_length; |
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239 | //Pointer to the map of predecessors arcs. |
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240 | PredMap *_pred; |
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241 | //Indicates if _pred is locally allocated (true) or not. |
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242 | bool local_pred; |
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243 | //Pointer to the map of distances. |
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244 | DistMap *_dist; |
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245 | //Indicates if _dist is locally allocated (true) or not. |
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246 | bool local_dist; |
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247 | //Pointer to the map of processed status of the nodes. |
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248 | ProcessedMap *_processed; |
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249 | //Indicates if _processed is locally allocated (true) or not. |
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250 | bool local_processed; |
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251 | //Pointer to the heap cross references. |
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252 | HeapCrossRef *_heap_cross_ref; |
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253 | //Indicates if _heap_cross_ref is locally allocated (true) or not. |
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254 | bool local_heap_cross_ref; |
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255 | //Pointer to the heap. |
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256 | Heap *_heap; |
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257 | //Indicates if _heap is locally allocated (true) or not. |
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258 | bool local_heap; |
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259 | |
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260 | //Creates the maps if necessary. |
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261 | void create_maps() |
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262 | { |
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263 | if(!_pred) { |
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264 | local_pred = true; |
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265 | _pred = Traits::createPredMap(*G); |
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266 | } |
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267 | if(!_dist) { |
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268 | local_dist = true; |
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269 | _dist = Traits::createDistMap(*G); |
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270 | } |
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271 | if(!_processed) { |
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272 | local_processed = true; |
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273 | _processed = Traits::createProcessedMap(*G); |
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274 | } |
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275 | if (!_heap_cross_ref) { |
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276 | local_heap_cross_ref = true; |
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277 | _heap_cross_ref = Traits::createHeapCrossRef(*G); |
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278 | } |
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279 | if (!_heap) { |
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280 | local_heap = true; |
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281 | _heap = Traits::createHeap(*_heap_cross_ref); |
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282 | } |
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283 | } |
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284 | |
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285 | public: |
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286 | |
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287 | typedef Dijkstra Create; |
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288 | |
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289 | ///\name Named Template Parameters |
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290 | |
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291 | ///@{ |
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292 | |
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293 | template <class T> |
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294 | struct SetPredMapTraits : public Traits { |
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295 | typedef T PredMap; |
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296 | static PredMap *createPredMap(const Digraph &) |
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297 | { |
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298 | LEMON_ASSERT(false, "PredMap is not initialized"); |
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299 | return 0; // ignore warnings |
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300 | } |
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301 | }; |
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302 | ///\brief \ref named-templ-param "Named parameter" for setting |
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303 | ///\c PredMap type. |
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304 | /// |
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305 | ///\ref named-templ-param "Named parameter" for setting |
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306 | ///\c PredMap type. |
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307 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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308 | template <class T> |
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309 | struct SetPredMap |
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310 | : public Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > { |
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311 | typedef Dijkstra< Digraph, LengthMap, SetPredMapTraits<T> > Create; |
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312 | }; |
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313 | |
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314 | template <class T> |
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315 | struct SetDistMapTraits : public Traits { |
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316 | typedef T DistMap; |
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317 | static DistMap *createDistMap(const Digraph &) |
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318 | { |
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319 | LEMON_ASSERT(false, "DistMap is not initialized"); |
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320 | return 0; // ignore warnings |
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321 | } |
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322 | }; |
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323 | ///\brief \ref named-templ-param "Named parameter" for setting |
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324 | ///\c DistMap type. |
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325 | /// |
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326 | ///\ref named-templ-param "Named parameter" for setting |
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327 | ///\c DistMap type. |
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328 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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329 | template <class T> |
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330 | struct SetDistMap |
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331 | : public Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > { |
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332 | typedef Dijkstra< Digraph, LengthMap, SetDistMapTraits<T> > Create; |
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333 | }; |
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334 | |
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335 | template <class T> |
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336 | struct SetProcessedMapTraits : public Traits { |
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337 | typedef T ProcessedMap; |
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338 | static ProcessedMap *createProcessedMap(const Digraph &) |
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339 | { |
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340 | LEMON_ASSERT(false, "ProcessedMap is not initialized"); |
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341 | return 0; // ignore warnings |
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342 | } |
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343 | }; |
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344 | ///\brief \ref named-templ-param "Named parameter" for setting |
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345 | ///\c ProcessedMap type. |
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346 | /// |
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347 | ///\ref named-templ-param "Named parameter" for setting |
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348 | ///\c ProcessedMap type. |
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349 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
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350 | template <class T> |
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351 | struct SetProcessedMap |
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352 | : public Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > { |
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353 | typedef Dijkstra< Digraph, LengthMap, SetProcessedMapTraits<T> > Create; |
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354 | }; |
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355 | |
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356 | struct SetStandardProcessedMapTraits : public Traits { |
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357 | typedef typename Digraph::template NodeMap<bool> ProcessedMap; |
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358 | static ProcessedMap *createProcessedMap(const Digraph &g) |
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359 | { |
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360 | return new ProcessedMap(g); |
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361 | } |
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362 | }; |
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363 | ///\brief \ref named-templ-param "Named parameter" for setting |
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364 | ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
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365 | /// |
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366 | ///\ref named-templ-param "Named parameter" for setting |
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367 | ///\c ProcessedMap type to be <tt>Digraph::NodeMap<bool></tt>. |
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368 | ///If you don't set it explicitly, it will be automatically allocated. |
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369 | struct SetStandardProcessedMap |
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370 | : public Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits > { |
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371 | typedef Dijkstra< Digraph, LengthMap, SetStandardProcessedMapTraits > |
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372 | Create; |
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373 | }; |
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374 | |
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375 | template <class H, class CR> |
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376 | struct SetHeapTraits : public Traits { |
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377 | typedef CR HeapCrossRef; |
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378 | typedef H Heap; |
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379 | static HeapCrossRef *createHeapCrossRef(const Digraph &) { |
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380 | LEMON_ASSERT(false, "HeapCrossRef is not initialized"); |
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381 | return 0; // ignore warnings |
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382 | } |
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383 | static Heap *createHeap(HeapCrossRef &) |
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384 | { |
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385 | LEMON_ASSERT(false, "Heap is not initialized"); |
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386 | return 0; // ignore warnings |
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387 | } |
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388 | }; |
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389 | ///\brief \ref named-templ-param "Named parameter" for setting |
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390 | ///heap and cross reference types |
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391 | /// |
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392 | ///\ref named-templ-param "Named parameter" for setting heap and cross |
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393 | ///reference types. If this named parameter is used, then external |
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394 | ///heap and cross reference objects must be passed to the algorithm |
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395 | ///using the \ref heap() function before calling \ref run(Node) "run()" |
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396 | ///or \ref init(). |
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397 | ///\sa SetStandardHeap |
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398 | template <class H, class CR = typename Digraph::template NodeMap<int> > |
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399 | struct SetHeap |
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400 | : public Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > { |
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401 | typedef Dijkstra< Digraph, LengthMap, SetHeapTraits<H, CR> > Create; |
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402 | }; |
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403 | |
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404 | template <class H, class CR> |
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405 | struct SetStandardHeapTraits : public Traits { |
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406 | typedef CR HeapCrossRef; |
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407 | typedef H Heap; |
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408 | static HeapCrossRef *createHeapCrossRef(const Digraph &G) { |
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409 | return new HeapCrossRef(G); |
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410 | } |
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411 | static Heap *createHeap(HeapCrossRef &R) |
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412 | { |
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413 | return new Heap(R); |
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414 | } |
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415 | }; |
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416 | ///\brief \ref named-templ-param "Named parameter" for setting |
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417 | ///heap and cross reference types with automatic allocation |
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418 | /// |
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419 | ///\ref named-templ-param "Named parameter" for setting heap and cross |
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420 | ///reference types with automatic allocation. |
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421 | ///They should have standard constructor interfaces to be able to |
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422 | ///automatically created by the algorithm (i.e. the digraph should be |
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423 | ///passed to the constructor of the cross reference and the cross |
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424 | ///reference should be passed to the constructor of the heap). |
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425 | ///However external heap and cross reference objects could also be |
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426 | ///passed to the algorithm using the \ref heap() function before |
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427 | ///calling \ref run(Node) "run()" or \ref init(). |
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428 | ///\sa SetHeap |
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429 | template <class H, class CR = typename Digraph::template NodeMap<int> > |
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430 | struct SetStandardHeap |
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431 | : public Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> > { |
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432 | typedef Dijkstra< Digraph, LengthMap, SetStandardHeapTraits<H, CR> > |
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433 | Create; |
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434 | }; |
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435 | |
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436 | template <class T> |
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437 | struct SetOperationTraitsTraits : public Traits { |
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438 | typedef T OperationTraits; |
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439 | }; |
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440 | |
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441 | /// \brief \ref named-templ-param "Named parameter" for setting |
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442 | ///\c OperationTraits type |
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443 | /// |
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444 | ///\ref named-templ-param "Named parameter" for setting |
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445 | ///\c OperationTraits type. |
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446 | template <class T> |
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447 | struct SetOperationTraits |
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448 | : public Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> > { |
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449 | typedef Dijkstra<Digraph, LengthMap, SetOperationTraitsTraits<T> > |
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450 | Create; |
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451 | }; |
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452 | |
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453 | ///@} |
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454 | |
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455 | protected: |
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456 | |
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457 | Dijkstra() {} |
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458 | |
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459 | public: |
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460 | |
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461 | ///Constructor. |
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462 | |
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463 | ///Constructor. |
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464 | ///\param g The digraph the algorithm runs on. |
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465 | ///\param length The length map used by the algorithm. |
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466 | Dijkstra(const Digraph& g, const LengthMap& length) : |
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467 | G(&g), _length(&length), |
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468 | _pred(NULL), local_pred(false), |
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469 | _dist(NULL), local_dist(false), |
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470 | _processed(NULL), local_processed(false), |
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471 | _heap_cross_ref(NULL), local_heap_cross_ref(false), |
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472 | _heap(NULL), local_heap(false) |
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473 | { } |
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474 | |
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475 | ///Destructor. |
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476 | ~Dijkstra() |
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477 | { |
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478 | if(local_pred) delete _pred; |
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479 | if(local_dist) delete _dist; |
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480 | if(local_processed) delete _processed; |
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481 | if(local_heap_cross_ref) delete _heap_cross_ref; |
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482 | if(local_heap) delete _heap; |
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483 | } |
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484 | |
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485 | ///Sets the length map. |
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486 | |
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487 | ///Sets the length map. |
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488 | ///\return <tt> (*this) </tt> |
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489 | Dijkstra &lengthMap(const LengthMap &m) |
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490 | { |
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491 | _length = &m; |
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492 | return *this; |
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493 | } |
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494 | |
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495 | ///Sets the map that stores the predecessor arcs. |
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496 | |
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497 | ///Sets the map that stores the predecessor arcs. |
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498 | ///If you don't use this function before calling \ref run(Node) "run()" |
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499 | ///or \ref init(), an instance will be allocated automatically. |
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500 | ///The destructor deallocates this automatically allocated map, |
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501 | ///of course. |
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502 | ///\return <tt> (*this) </tt> |
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503 | Dijkstra &predMap(PredMap &m) |
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504 | { |
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505 | if(local_pred) { |
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506 | delete _pred; |
---|
507 | local_pred=false; |
---|
508 | } |
---|
509 | _pred = &m; |
---|
510 | return *this; |
---|
511 | } |
---|
512 | |
---|
513 | ///Sets the map that indicates which nodes are processed. |
---|
514 | |
---|
515 | ///Sets the map that indicates which nodes are processed. |
---|
516 | ///If you don't use this function before calling \ref run(Node) "run()" |
---|
517 | ///or \ref init(), an instance will be allocated automatically. |
---|
518 | ///The destructor deallocates this automatically allocated map, |
---|
519 | ///of course. |
---|
520 | ///\return <tt> (*this) </tt> |
---|
521 | Dijkstra &processedMap(ProcessedMap &m) |
---|
522 | { |
---|
523 | if(local_processed) { |
---|
524 | delete _processed; |
---|
525 | local_processed=false; |
---|
526 | } |
---|
527 | _processed = &m; |
---|
528 | return *this; |
---|
529 | } |
---|
530 | |
---|
531 | ///Sets the map that stores the distances of the nodes. |
---|
532 | |
---|
533 | ///Sets the map that stores the distances of the nodes calculated by the |
---|
534 | ///algorithm. |
---|
535 | ///If you don't use this function before calling \ref run(Node) "run()" |
---|
536 | ///or \ref init(), an instance will be allocated automatically. |
---|
537 | ///The destructor deallocates this automatically allocated map, |
---|
538 | ///of course. |
---|
539 | ///\return <tt> (*this) </tt> |
---|
540 | Dijkstra &distMap(DistMap &m) |
---|
541 | { |
---|
542 | if(local_dist) { |
---|
543 | delete _dist; |
---|
544 | local_dist=false; |
---|
545 | } |
---|
546 | _dist = &m; |
---|
547 | return *this; |
---|
548 | } |
---|
549 | |
---|
550 | ///Sets the heap and the cross reference used by algorithm. |
---|
551 | |
---|
552 | ///Sets the heap and the cross reference used by algorithm. |
---|
553 | ///If you don't use this function before calling \ref run(Node) "run()" |
---|
554 | ///or \ref init(), heap and cross reference instances will be |
---|
555 | ///allocated automatically. |
---|
556 | ///The destructor deallocates these automatically allocated objects, |
---|
557 | ///of course. |
---|
558 | ///\return <tt> (*this) </tt> |
---|
559 | Dijkstra &heap(Heap& hp, HeapCrossRef &cr) |
---|
560 | { |
---|
561 | if(local_heap_cross_ref) { |
---|
562 | delete _heap_cross_ref; |
---|
563 | local_heap_cross_ref=false; |
---|
564 | } |
---|
565 | _heap_cross_ref = &cr; |
---|
566 | if(local_heap) { |
---|
567 | delete _heap; |
---|
568 | local_heap=false; |
---|
569 | } |
---|
570 | _heap = &hp; |
---|
571 | return *this; |
---|
572 | } |
---|
573 | |
---|
574 | private: |
---|
575 | |
---|
576 | void finalizeNodeData(Node v,Value dst) |
---|
577 | { |
---|
578 | _processed->set(v,true); |
---|
579 | _dist->set(v, dst); |
---|
580 | } |
---|
581 | |
---|
582 | public: |
---|
583 | |
---|
584 | ///\name Execution Control |
---|
585 | ///The simplest way to execute the %Dijkstra algorithm is to use |
---|
586 | ///one of the member functions called \ref run(Node) "run()".\n |
---|
587 | ///If you need better control on the execution, you have to call |
---|
588 | ///\ref init() first, then you can add several source nodes with |
---|
589 | ///\ref addSource(). Finally the actual path computation can be |
---|
590 | ///performed with one of the \ref start() functions. |
---|
591 | |
---|
592 | ///@{ |
---|
593 | |
---|
594 | ///\brief Initializes the internal data structures. |
---|
595 | /// |
---|
596 | ///Initializes the internal data structures. |
---|
597 | void init() |
---|
598 | { |
---|
599 | create_maps(); |
---|
600 | _heap->clear(); |
---|
601 | for ( NodeIt u(*G) ; u!=INVALID ; ++u ) { |
---|
602 | _pred->set(u,INVALID); |
---|
603 | _processed->set(u,false); |
---|
604 | _heap_cross_ref->set(u,Heap::PRE_HEAP); |
---|
605 | } |
---|
606 | } |
---|
607 | |
---|
608 | ///Adds a new source node. |
---|
609 | |
---|
610 | ///Adds a new source node to the priority heap. |
---|
611 | ///The optional second parameter is the initial distance of the node. |
---|
612 | /// |
---|
613 | ///The function checks if the node has already been added to the heap and |
---|
614 | ///it is pushed to the heap only if either it was not in the heap |
---|
615 | ///or the shortest path found till then is shorter than \c dst. |
---|
616 | void addSource(Node s,Value dst=OperationTraits::zero()) |
---|
617 | { |
---|
618 | if(_heap->state(s) != Heap::IN_HEAP) { |
---|
619 | _heap->push(s,dst); |
---|
620 | } else if(OperationTraits::less((*_heap)[s], dst)) { |
---|
621 | _heap->set(s,dst); |
---|
622 | _pred->set(s,INVALID); |
---|
623 | } |
---|
624 | } |
---|
625 | |
---|
626 | ///Processes the next node in the priority heap |
---|
627 | |
---|
628 | ///Processes the next node in the priority heap. |
---|
629 | /// |
---|
630 | ///\return The processed node. |
---|
631 | /// |
---|
632 | ///\warning The priority heap must not be empty. |
---|
633 | Node processNextNode() |
---|
634 | { |
---|
635 | Node v=_heap->top(); |
---|
636 | Value oldvalue=_heap->prio(); |
---|
637 | _heap->pop(); |
---|
638 | finalizeNodeData(v,oldvalue); |
---|
639 | |
---|
640 | for(OutArcIt e(*G,v); e!=INVALID; ++e) { |
---|
641 | Node w=G->target(e); |
---|
642 | switch(_heap->state(w)) { |
---|
643 | case Heap::PRE_HEAP: |
---|
644 | _heap->push(w,OperationTraits::plus(oldvalue, (*_length)[e])); |
---|
645 | _pred->set(w,e); |
---|
646 | break; |
---|
647 | case Heap::IN_HEAP: |
---|
648 | { |
---|
649 | Value newvalue = OperationTraits::plus(oldvalue, (*_length)[e]); |
---|
650 | if ( OperationTraits::less(newvalue, (*_heap)[w]) ) { |
---|
651 | _heap->decrease(w, newvalue); |
---|
652 | _pred->set(w,e); |
---|
653 | } |
---|
654 | } |
---|
655 | break; |
---|
656 | case Heap::POST_HEAP: |
---|
657 | break; |
---|
658 | } |
---|
659 | } |
---|
660 | return v; |
---|
661 | } |
---|
662 | |
---|
663 | ///The next node to be processed. |
---|
664 | |
---|
665 | ///Returns the next node to be processed or \c INVALID if the |
---|
666 | ///priority heap is empty. |
---|
667 | Node nextNode() const |
---|
668 | { |
---|
669 | return !_heap->empty()?_heap->top():INVALID; |
---|
670 | } |
---|
671 | |
---|
672 | ///Returns \c false if there are nodes to be processed. |
---|
673 | |
---|
674 | ///Returns \c false if there are nodes to be processed |
---|
675 | ///in the priority heap. |
---|
676 | bool emptyQueue() const { return _heap->empty(); } |
---|
677 | |
---|
678 | ///Returns the number of the nodes to be processed. |
---|
679 | |
---|
680 | ///Returns the number of the nodes to be processed |
---|
681 | ///in the priority heap. |
---|
682 | int queueSize() const { return _heap->size(); } |
---|
683 | |
---|
684 | ///Executes the algorithm. |
---|
685 | |
---|
686 | ///Executes the algorithm. |
---|
687 | /// |
---|
688 | ///This method runs the %Dijkstra algorithm from the root node(s) |
---|
689 | ///in order to compute the shortest path to each node. |
---|
690 | /// |
---|
691 | ///The algorithm computes |
---|
692 | ///- the shortest path tree (forest), |
---|
693 | ///- the distance of each node from the root(s). |
---|
694 | /// |
---|
695 | ///\pre init() must be called and at least one root node should be |
---|
696 | ///added with addSource() before using this function. |
---|
697 | /// |
---|
698 | ///\note <tt>d.start()</tt> is just a shortcut of the following code. |
---|
699 | ///\code |
---|
700 | /// while ( !d.emptyQueue() ) { |
---|
701 | /// d.processNextNode(); |
---|
702 | /// } |
---|
703 | ///\endcode |
---|
704 | void start() |
---|
705 | { |
---|
706 | while ( !emptyQueue() ) processNextNode(); |
---|
707 | } |
---|
708 | |
---|
709 | ///Executes the algorithm until the given target node is processed. |
---|
710 | |
---|
711 | ///Executes the algorithm until the given target node is processed. |
---|
712 | /// |
---|
713 | ///This method runs the %Dijkstra algorithm from the root node(s) |
---|
714 | ///in order to compute the shortest path to \c t. |
---|
715 | /// |
---|
716 | ///The algorithm computes |
---|
717 | ///- the shortest path to \c t, |
---|
718 | ///- the distance of \c t from the root(s). |
---|
719 | /// |
---|
720 | ///\pre init() must be called and at least one root node should be |
---|
721 | ///added with addSource() before using this function. |
---|
722 | void start(Node t) |
---|
723 | { |
---|
724 | while ( !_heap->empty() && _heap->top()!=t ) processNextNode(); |
---|
725 | if ( !_heap->empty() ) { |
---|
726 | finalizeNodeData(_heap->top(),_heap->prio()); |
---|
727 | _heap->pop(); |
---|
728 | } |
---|
729 | } |
---|
730 | |
---|
731 | ///Executes the algorithm until a condition is met. |
---|
732 | |
---|
733 | ///Executes the algorithm until a condition is met. |
---|
734 | /// |
---|
735 | ///This method runs the %Dijkstra algorithm from the root node(s) in |
---|
736 | ///order to compute the shortest path to a node \c v with |
---|
737 | /// <tt>nm[v]</tt> true, if such a node can be found. |
---|
738 | /// |
---|
739 | ///\param nm A \c bool (or convertible) node map. The algorithm |
---|
740 | ///will stop when it reaches a node \c v with <tt>nm[v]</tt> true. |
---|
741 | /// |
---|
742 | ///\return The reached node \c v with <tt>nm[v]</tt> true or |
---|
743 | ///\c INVALID if no such node was found. |
---|
744 | /// |
---|
745 | ///\pre init() must be called and at least one root node should be |
---|
746 | ///added with addSource() before using this function. |
---|
747 | template<class NodeBoolMap> |
---|
748 | Node start(const NodeBoolMap &nm) |
---|
749 | { |
---|
750 | while ( !_heap->empty() && !nm[_heap->top()] ) processNextNode(); |
---|
751 | if ( _heap->empty() ) return INVALID; |
---|
752 | finalizeNodeData(_heap->top(),_heap->prio()); |
---|
753 | return _heap->top(); |
---|
754 | } |
---|
755 | |
---|
756 | ///Runs the algorithm from the given source node. |
---|
757 | |
---|
758 | ///This method runs the %Dijkstra algorithm from node \c s |
---|
759 | ///in order to compute the shortest path to each node. |
---|
760 | /// |
---|
761 | ///The algorithm computes |
---|
762 | ///- the shortest path tree, |
---|
763 | ///- the distance of each node from the root. |
---|
764 | /// |
---|
765 | ///\note <tt>d.run(s)</tt> is just a shortcut of the following code. |
---|
766 | ///\code |
---|
767 | /// d.init(); |
---|
768 | /// d.addSource(s); |
---|
769 | /// d.start(); |
---|
770 | ///\endcode |
---|
771 | void run(Node s) { |
---|
772 | init(); |
---|
773 | addSource(s); |
---|
774 | start(); |
---|
775 | } |
---|
776 | |
---|
777 | ///Finds the shortest path between \c s and \c t. |
---|
778 | |
---|
779 | ///This method runs the %Dijkstra algorithm from node \c s |
---|
780 | ///in order to compute the shortest path to node \c t |
---|
781 | ///(it stops searching when \c t is processed). |
---|
782 | /// |
---|
783 | ///\return \c true if \c t is reachable form \c s. |
---|
784 | /// |
---|
785 | ///\note Apart from the return value, <tt>d.run(s,t)</tt> is just a |
---|
786 | ///shortcut of the following code. |
---|
787 | ///\code |
---|
788 | /// d.init(); |
---|
789 | /// d.addSource(s); |
---|
790 | /// d.start(t); |
---|
791 | ///\endcode |
---|
792 | bool run(Node s,Node t) { |
---|
793 | init(); |
---|
794 | addSource(s); |
---|
795 | start(t); |
---|
796 | return (*_heap_cross_ref)[t] == Heap::POST_HEAP; |
---|
797 | } |
---|
798 | |
---|
799 | ///@} |
---|
800 | |
---|
801 | ///\name Query Functions |
---|
802 | ///The results of the %Dijkstra algorithm can be obtained using these |
---|
803 | ///functions.\n |
---|
804 | ///Either \ref run(Node) "run()" or \ref start() should be called |
---|
805 | ///before using them. |
---|
806 | |
---|
807 | ///@{ |
---|
808 | |
---|
809 | ///The shortest path to a node. |
---|
810 | |
---|
811 | ///Returns the shortest path to a node. |
---|
812 | /// |
---|
813 | ///\warning \c t should be reached from the root(s). |
---|
814 | /// |
---|
815 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
816 | ///must be called before using this function. |
---|
817 | Path path(Node t) const { return Path(*G, *_pred, t); } |
---|
818 | |
---|
819 | ///The distance of a node from the root(s). |
---|
820 | |
---|
821 | ///Returns the distance of a node from the root(s). |
---|
822 | /// |
---|
823 | ///\warning If node \c v is not reached from the root(s), then |
---|
824 | ///the return value of this function is undefined. |
---|
825 | /// |
---|
826 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
827 | ///must be called before using this function. |
---|
828 | Value dist(Node v) const { return (*_dist)[v]; } |
---|
829 | |
---|
830 | ///Returns the 'previous arc' of the shortest path tree for a node. |
---|
831 | |
---|
832 | ///This function returns the 'previous arc' of the shortest path |
---|
833 | ///tree for the node \c v, i.e. it returns the last arc of a |
---|
834 | ///shortest path from a root to \c v. It is \c INVALID if \c v |
---|
835 | ///is not reached from the root(s) or if \c v is a root. |
---|
836 | /// |
---|
837 | ///The shortest path tree used here is equal to the shortest path |
---|
838 | ///tree used in \ref predNode(). |
---|
839 | /// |
---|
840 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
841 | ///must be called before using this function. |
---|
842 | Arc predArc(Node v) const { return (*_pred)[v]; } |
---|
843 | |
---|
844 | ///Returns the 'previous node' of the shortest path tree for a node. |
---|
845 | |
---|
846 | ///This function returns the 'previous node' of the shortest path |
---|
847 | ///tree for the node \c v, i.e. it returns the last but one node |
---|
848 | ///from a shortest path from a root to \c v. It is \c INVALID |
---|
849 | ///if \c v is not reached from the root(s) or if \c v is a root. |
---|
850 | /// |
---|
851 | ///The shortest path tree used here is equal to the shortest path |
---|
852 | ///tree used in \ref predArc(). |
---|
853 | /// |
---|
854 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
855 | ///must be called before using this function. |
---|
856 | Node predNode(Node v) const { return (*_pred)[v]==INVALID ? INVALID: |
---|
857 | G->source((*_pred)[v]); } |
---|
858 | |
---|
859 | ///\brief Returns a const reference to the node map that stores the |
---|
860 | ///distances of the nodes. |
---|
861 | /// |
---|
862 | ///Returns a const reference to the node map that stores the distances |
---|
863 | ///of the nodes calculated by the algorithm. |
---|
864 | /// |
---|
865 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
866 | ///must be called before using this function. |
---|
867 | const DistMap &distMap() const { return *_dist;} |
---|
868 | |
---|
869 | ///\brief Returns a const reference to the node map that stores the |
---|
870 | ///predecessor arcs. |
---|
871 | /// |
---|
872 | ///Returns a const reference to the node map that stores the predecessor |
---|
873 | ///arcs, which form the shortest path tree. |
---|
874 | /// |
---|
875 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
876 | ///must be called before using this function. |
---|
877 | const PredMap &predMap() const { return *_pred;} |
---|
878 | |
---|
879 | ///Checks if a node is reached from the root(s). |
---|
880 | |
---|
881 | ///Returns \c true if \c v is reached from the root(s). |
---|
882 | /// |
---|
883 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
884 | ///must be called before using this function. |
---|
885 | bool reached(Node v) const { return (*_heap_cross_ref)[v] != |
---|
886 | Heap::PRE_HEAP; } |
---|
887 | |
---|
888 | ///Checks if a node is processed. |
---|
889 | |
---|
890 | ///Returns \c true if \c v is processed, i.e. the shortest |
---|
891 | ///path to \c v has already found. |
---|
892 | /// |
---|
893 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
894 | ///must be called before using this function. |
---|
895 | bool processed(Node v) const { return (*_heap_cross_ref)[v] == |
---|
896 | Heap::POST_HEAP; } |
---|
897 | |
---|
898 | ///The current distance of a node from the root(s). |
---|
899 | |
---|
900 | ///Returns the current distance of a node from the root(s). |
---|
901 | ///It may be decreased in the following processes. |
---|
902 | /// |
---|
903 | ///\pre Either \ref run(Node) "run()" or \ref init() |
---|
904 | ///must be called before using this function and |
---|
905 | ///node \c v must be reached but not necessarily processed. |
---|
906 | Value currentDist(Node v) const { |
---|
907 | return processed(v) ? (*_dist)[v] : (*_heap)[v]; |
---|
908 | } |
---|
909 | |
---|
910 | ///@} |
---|
911 | }; |
---|
912 | |
---|
913 | |
---|
914 | ///Default traits class of dijkstra() function. |
---|
915 | |
---|
916 | ///Default traits class of dijkstra() function. |
---|
917 | ///\tparam GR The type of the digraph. |
---|
918 | ///\tparam LEN The type of the length map. |
---|
919 | template<class GR, class LEN> |
---|
920 | struct DijkstraWizardDefaultTraits |
---|
921 | { |
---|
922 | ///The type of the digraph the algorithm runs on. |
---|
923 | typedef GR Digraph; |
---|
924 | ///The type of the map that stores the arc lengths. |
---|
925 | |
---|
926 | ///The type of the map that stores the arc lengths. |
---|
927 | ///It must meet the \ref concepts::ReadMap "ReadMap" concept. |
---|
928 | typedef LEN LengthMap; |
---|
929 | ///The type of the length of the arcs. |
---|
930 | typedef typename LEN::Value Value; |
---|
931 | |
---|
932 | /// Operation traits for Dijkstra algorithm. |
---|
933 | |
---|
934 | /// This class defines the operations that are used in the algorithm. |
---|
935 | /// \see DijkstraDefaultOperationTraits |
---|
936 | typedef DijkstraDefaultOperationTraits<Value> OperationTraits; |
---|
937 | |
---|
938 | /// The cross reference type used by the heap. |
---|
939 | |
---|
940 | /// The cross reference type used by the heap. |
---|
941 | /// Usually it is \c Digraph::NodeMap<int>. |
---|
942 | typedef typename Digraph::template NodeMap<int> HeapCrossRef; |
---|
943 | ///Instantiates a \ref HeapCrossRef. |
---|
944 | |
---|
945 | ///This function instantiates a \ref HeapCrossRef. |
---|
946 | /// \param g is the digraph, to which we would like to define the |
---|
947 | /// HeapCrossRef. |
---|
948 | static HeapCrossRef *createHeapCrossRef(const Digraph &g) |
---|
949 | { |
---|
950 | return new HeapCrossRef(g); |
---|
951 | } |
---|
952 | |
---|
953 | ///The heap type used by the Dijkstra algorithm. |
---|
954 | |
---|
955 | ///The heap type used by the Dijkstra algorithm. |
---|
956 | /// |
---|
957 | ///\sa BinHeap |
---|
958 | ///\sa Dijkstra |
---|
959 | typedef BinHeap<Value, typename Digraph::template NodeMap<int>, |
---|
960 | std::less<Value> > Heap; |
---|
961 | |
---|
962 | ///Instantiates a \ref Heap. |
---|
963 | |
---|
964 | ///This function instantiates a \ref Heap. |
---|
965 | /// \param r is the HeapCrossRef which is used. |
---|
966 | static Heap *createHeap(HeapCrossRef& r) |
---|
967 | { |
---|
968 | return new Heap(r); |
---|
969 | } |
---|
970 | |
---|
971 | ///\brief The type of the map that stores the predecessor |
---|
972 | ///arcs of the shortest paths. |
---|
973 | /// |
---|
974 | ///The type of the map that stores the predecessor |
---|
975 | ///arcs of the shortest paths. |
---|
976 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
977 | typedef typename Digraph::template NodeMap<typename Digraph::Arc> PredMap; |
---|
978 | ///Instantiates a PredMap. |
---|
979 | |
---|
980 | ///This function instantiates a PredMap. |
---|
981 | ///\param g is the digraph, to which we would like to define the |
---|
982 | ///PredMap. |
---|
983 | static PredMap *createPredMap(const Digraph &g) |
---|
984 | { |
---|
985 | return new PredMap(g); |
---|
986 | } |
---|
987 | |
---|
988 | ///The type of the map that indicates which nodes are processed. |
---|
989 | |
---|
990 | ///The type of the map that indicates which nodes are processed. |
---|
991 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
992 | ///By default it is a NullMap. |
---|
993 | typedef NullMap<typename Digraph::Node,bool> ProcessedMap; |
---|
994 | ///Instantiates a ProcessedMap. |
---|
995 | |
---|
996 | ///This function instantiates a ProcessedMap. |
---|
997 | ///\param g is the digraph, to which |
---|
998 | ///we would like to define the ProcessedMap. |
---|
999 | #ifdef DOXYGEN |
---|
1000 | static ProcessedMap *createProcessedMap(const Digraph &g) |
---|
1001 | #else |
---|
1002 | static ProcessedMap *createProcessedMap(const Digraph &) |
---|
1003 | #endif |
---|
1004 | { |
---|
1005 | return new ProcessedMap(); |
---|
1006 | } |
---|
1007 | |
---|
1008 | ///The type of the map that stores the distances of the nodes. |
---|
1009 | |
---|
1010 | ///The type of the map that stores the distances of the nodes. |
---|
1011 | ///It must meet the \ref concepts::WriteMap "WriteMap" concept. |
---|
1012 | typedef typename Digraph::template NodeMap<typename LEN::Value> DistMap; |
---|
1013 | ///Instantiates a DistMap. |
---|
1014 | |
---|
1015 | ///This function instantiates a DistMap. |
---|
1016 | ///\param g is the digraph, to which we would like to define |
---|
1017 | ///the DistMap |
---|
1018 | static DistMap *createDistMap(const Digraph &g) |
---|
1019 | { |
---|
1020 | return new DistMap(g); |
---|
1021 | } |
---|
1022 | |
---|
1023 | ///The type of the shortest paths. |
---|
1024 | |
---|
1025 | ///The type of the shortest paths. |
---|
1026 | ///It must meet the \ref concepts::Path "Path" concept. |
---|
1027 | typedef lemon::Path<Digraph> Path; |
---|
1028 | }; |
---|
1029 | |
---|
1030 | /// Default traits class used by DijkstraWizard |
---|
1031 | |
---|
1032 | /// To make it easier to use Dijkstra algorithm |
---|
1033 | /// we have created a wizard class. |
---|
1034 | /// This \ref DijkstraWizard class needs default traits, |
---|
1035 | /// as well as the \ref Dijkstra class. |
---|
1036 | /// The \ref DijkstraWizardBase is a class to be the default traits of the |
---|
1037 | /// \ref DijkstraWizard class. |
---|
1038 | template<typename GR, typename LEN> |
---|
1039 | class DijkstraWizardBase : public DijkstraWizardDefaultTraits<GR,LEN> |
---|
1040 | { |
---|
1041 | typedef DijkstraWizardDefaultTraits<GR,LEN> Base; |
---|
1042 | protected: |
---|
1043 | //The type of the nodes in the digraph. |
---|
1044 | typedef typename Base::Digraph::Node Node; |
---|
1045 | |
---|
1046 | //Pointer to the digraph the algorithm runs on. |
---|
1047 | void *_g; |
---|
1048 | //Pointer to the length map. |
---|
1049 | void *_length; |
---|
1050 | //Pointer to the map of processed nodes. |
---|
1051 | void *_processed; |
---|
1052 | //Pointer to the map of predecessors arcs. |
---|
1053 | void *_pred; |
---|
1054 | //Pointer to the map of distances. |
---|
1055 | void *_dist; |
---|
1056 | //Pointer to the shortest path to the target node. |
---|
1057 | void *_path; |
---|
1058 | //Pointer to the distance of the target node. |
---|
1059 | void *_di; |
---|
1060 | |
---|
1061 | public: |
---|
1062 | /// Constructor. |
---|
1063 | |
---|
1064 | /// This constructor does not require parameters, therefore it initiates |
---|
1065 | /// all of the attributes to \c 0. |
---|
1066 | DijkstraWizardBase() : _g(0), _length(0), _processed(0), _pred(0), |
---|
1067 | _dist(0), _path(0), _di(0) {} |
---|
1068 | |
---|
1069 | /// Constructor. |
---|
1070 | |
---|
1071 | /// This constructor requires two parameters, |
---|
1072 | /// others are initiated to \c 0. |
---|
1073 | /// \param g The digraph the algorithm runs on. |
---|
1074 | /// \param l The length map. |
---|
1075 | DijkstraWizardBase(const GR &g,const LEN &l) : |
---|
1076 | _g(reinterpret_cast<void*>(const_cast<GR*>(&g))), |
---|
1077 | _length(reinterpret_cast<void*>(const_cast<LEN*>(&l))), |
---|
1078 | _processed(0), _pred(0), _dist(0), _path(0), _di(0) {} |
---|
1079 | |
---|
1080 | }; |
---|
1081 | |
---|
1082 | /// Auxiliary class for the function-type interface of Dijkstra algorithm. |
---|
1083 | |
---|
1084 | /// This auxiliary class is created to implement the |
---|
1085 | /// \ref dijkstra() "function-type interface" of \ref Dijkstra algorithm. |
---|
1086 | /// It does not have own \ref run(Node) "run()" method, it uses the |
---|
1087 | /// functions and features of the plain \ref Dijkstra. |
---|
1088 | /// |
---|
1089 | /// This class should only be used through the \ref dijkstra() function, |
---|
1090 | /// which makes it easier to use the algorithm. |
---|
1091 | template<class TR> |
---|
1092 | class DijkstraWizard : public TR |
---|
1093 | { |
---|
1094 | typedef TR Base; |
---|
1095 | |
---|
1096 | ///The type of the digraph the algorithm runs on. |
---|
1097 | typedef typename TR::Digraph Digraph; |
---|
1098 | |
---|
1099 | typedef typename Digraph::Node Node; |
---|
1100 | typedef typename Digraph::NodeIt NodeIt; |
---|
1101 | typedef typename Digraph::Arc Arc; |
---|
1102 | typedef typename Digraph::OutArcIt OutArcIt; |
---|
1103 | |
---|
1104 | ///The type of the map that stores the arc lengths. |
---|
1105 | typedef typename TR::LengthMap LengthMap; |
---|
1106 | ///The type of the length of the arcs. |
---|
1107 | typedef typename LengthMap::Value Value; |
---|
1108 | ///\brief The type of the map that stores the predecessor |
---|
1109 | ///arcs of the shortest paths. |
---|
1110 | typedef typename TR::PredMap PredMap; |
---|
1111 | ///The type of the map that stores the distances of the nodes. |
---|
1112 | typedef typename TR::DistMap DistMap; |
---|
1113 | ///The type of the map that indicates which nodes are processed. |
---|
1114 | typedef typename TR::ProcessedMap ProcessedMap; |
---|
1115 | ///The type of the shortest paths |
---|
1116 | typedef typename TR::Path Path; |
---|
1117 | ///The heap type used by the dijkstra algorithm. |
---|
1118 | typedef typename TR::Heap Heap; |
---|
1119 | |
---|
1120 | public: |
---|
1121 | |
---|
1122 | /// Constructor. |
---|
1123 | DijkstraWizard() : TR() {} |
---|
1124 | |
---|
1125 | /// Constructor that requires parameters. |
---|
1126 | |
---|
1127 | /// Constructor that requires parameters. |
---|
1128 | /// These parameters will be the default values for the traits class. |
---|
1129 | /// \param g The digraph the algorithm runs on. |
---|
1130 | /// \param l The length map. |
---|
1131 | DijkstraWizard(const Digraph &g, const LengthMap &l) : |
---|
1132 | TR(g,l) {} |
---|
1133 | |
---|
1134 | ///Copy constructor |
---|
1135 | DijkstraWizard(const TR &b) : TR(b) {} |
---|
1136 | |
---|
1137 | ~DijkstraWizard() {} |
---|
1138 | |
---|
1139 | ///Runs Dijkstra algorithm from the given source node. |
---|
1140 | |
---|
1141 | ///This method runs %Dijkstra algorithm from the given source node |
---|
1142 | ///in order to compute the shortest path to each node. |
---|
1143 | void run(Node s) |
---|
1144 | { |
---|
1145 | Dijkstra<Digraph,LengthMap,TR> |
---|
1146 | dijk(*reinterpret_cast<const Digraph*>(Base::_g), |
---|
1147 | *reinterpret_cast<const LengthMap*>(Base::_length)); |
---|
1148 | if (Base::_pred) |
---|
1149 | dijk.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
---|
1150 | if (Base::_dist) |
---|
1151 | dijk.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
---|
1152 | if (Base::_processed) |
---|
1153 | dijk.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
---|
1154 | dijk.run(s); |
---|
1155 | } |
---|
1156 | |
---|
1157 | ///Finds the shortest path between \c s and \c t. |
---|
1158 | |
---|
1159 | ///This method runs the %Dijkstra algorithm from node \c s |
---|
1160 | ///in order to compute the shortest path to node \c t |
---|
1161 | ///(it stops searching when \c t is processed). |
---|
1162 | /// |
---|
1163 | ///\return \c true if \c t is reachable form \c s. |
---|
1164 | bool run(Node s, Node t) |
---|
1165 | { |
---|
1166 | Dijkstra<Digraph,LengthMap,TR> |
---|
1167 | dijk(*reinterpret_cast<const Digraph*>(Base::_g), |
---|
1168 | *reinterpret_cast<const LengthMap*>(Base::_length)); |
---|
1169 | if (Base::_pred) |
---|
1170 | dijk.predMap(*reinterpret_cast<PredMap*>(Base::_pred)); |
---|
1171 | if (Base::_dist) |
---|
1172 | dijk.distMap(*reinterpret_cast<DistMap*>(Base::_dist)); |
---|
1173 | if (Base::_processed) |
---|
1174 | dijk.processedMap(*reinterpret_cast<ProcessedMap*>(Base::_processed)); |
---|
1175 | dijk.run(s,t); |
---|
1176 | if (Base::_path) |
---|
1177 | *reinterpret_cast<Path*>(Base::_path) = dijk.path(t); |
---|
1178 | if (Base::_di) |
---|
1179 | *reinterpret_cast<Value*>(Base::_di) = dijk.dist(t); |
---|
1180 | return dijk.reached(t); |
---|
1181 | } |
---|
1182 | |
---|
1183 | template<class T> |
---|
1184 | struct SetPredMapBase : public Base { |
---|
1185 | typedef T PredMap; |
---|
1186 | static PredMap *createPredMap(const Digraph &) { return 0; }; |
---|
1187 | SetPredMapBase(const TR &b) : TR(b) {} |
---|
1188 | }; |
---|
1189 | ///\brief \ref named-func-param "Named parameter" |
---|
1190 | ///for setting PredMap object. |
---|
1191 | /// |
---|
1192 | ///\ref named-func-param "Named parameter" |
---|
1193 | ///for setting PredMap object. |
---|
1194 | template<class T> |
---|
1195 | DijkstraWizard<SetPredMapBase<T> > predMap(const T &t) |
---|
1196 | { |
---|
1197 | Base::_pred=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
1198 | return DijkstraWizard<SetPredMapBase<T> >(*this); |
---|
1199 | } |
---|
1200 | |
---|
1201 | template<class T> |
---|
1202 | struct SetDistMapBase : public Base { |
---|
1203 | typedef T DistMap; |
---|
1204 | static DistMap *createDistMap(const Digraph &) { return 0; }; |
---|
1205 | SetDistMapBase(const TR &b) : TR(b) {} |
---|
1206 | }; |
---|
1207 | ///\brief \ref named-func-param "Named parameter" |
---|
1208 | ///for setting DistMap object. |
---|
1209 | /// |
---|
1210 | ///\ref named-func-param "Named parameter" |
---|
1211 | ///for setting DistMap object. |
---|
1212 | template<class T> |
---|
1213 | DijkstraWizard<SetDistMapBase<T> > distMap(const T &t) |
---|
1214 | { |
---|
1215 | Base::_dist=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
1216 | return DijkstraWizard<SetDistMapBase<T> >(*this); |
---|
1217 | } |
---|
1218 | |
---|
1219 | template<class T> |
---|
1220 | struct SetProcessedMapBase : public Base { |
---|
1221 | typedef T ProcessedMap; |
---|
1222 | static ProcessedMap *createProcessedMap(const Digraph &) { return 0; }; |
---|
1223 | SetProcessedMapBase(const TR &b) : TR(b) {} |
---|
1224 | }; |
---|
1225 | ///\brief \ref named-func-param "Named parameter" |
---|
1226 | ///for setting ProcessedMap object. |
---|
1227 | /// |
---|
1228 | /// \ref named-func-param "Named parameter" |
---|
1229 | ///for setting ProcessedMap object. |
---|
1230 | template<class T> |
---|
1231 | DijkstraWizard<SetProcessedMapBase<T> > processedMap(const T &t) |
---|
1232 | { |
---|
1233 | Base::_processed=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
1234 | return DijkstraWizard<SetProcessedMapBase<T> >(*this); |
---|
1235 | } |
---|
1236 | |
---|
1237 | template<class T> |
---|
1238 | struct SetPathBase : public Base { |
---|
1239 | typedef T Path; |
---|
1240 | SetPathBase(const TR &b) : TR(b) {} |
---|
1241 | }; |
---|
1242 | ///\brief \ref named-func-param "Named parameter" |
---|
1243 | ///for getting the shortest path to the target node. |
---|
1244 | /// |
---|
1245 | ///\ref named-func-param "Named parameter" |
---|
1246 | ///for getting the shortest path to the target node. |
---|
1247 | template<class T> |
---|
1248 | DijkstraWizard<SetPathBase<T> > path(const T &t) |
---|
1249 | { |
---|
1250 | Base::_path=reinterpret_cast<void*>(const_cast<T*>(&t)); |
---|
1251 | return DijkstraWizard<SetPathBase<T> >(*this); |
---|
1252 | } |
---|
1253 | |
---|
1254 | ///\brief \ref named-func-param "Named parameter" |
---|
1255 | ///for getting the distance of the target node. |
---|
1256 | /// |
---|
1257 | ///\ref named-func-param "Named parameter" |
---|
1258 | ///for getting the distance of the target node. |
---|
1259 | DijkstraWizard dist(const Value &d) |
---|
1260 | { |
---|
1261 | Base::_di=reinterpret_cast<void*>(const_cast<Value*>(&d)); |
---|
1262 | return *this; |
---|
1263 | } |
---|
1264 | |
---|
1265 | }; |
---|
1266 | |
---|
1267 | ///Function-type interface for Dijkstra algorithm. |
---|
1268 | |
---|
1269 | /// \ingroup shortest_path |
---|
1270 | ///Function-type interface for Dijkstra algorithm. |
---|
1271 | /// |
---|
1272 | ///This function also has several \ref named-func-param "named parameters", |
---|
1273 | ///they are declared as the members of class \ref DijkstraWizard. |
---|
1274 | ///The following examples show how to use these parameters. |
---|
1275 | ///\code |
---|
1276 | /// // Compute shortest path from node s to each node |
---|
1277 | /// dijkstra(g,length).predMap(preds).distMap(dists).run(s); |
---|
1278 | /// |
---|
1279 | /// // Compute shortest path from s to t |
---|
1280 | /// bool reached = dijkstra(g,length).path(p).dist(d).run(s,t); |
---|
1281 | ///\endcode |
---|
1282 | ///\warning Don't forget to put the \ref DijkstraWizard::run(Node) "run()" |
---|
1283 | ///to the end of the parameter list. |
---|
1284 | ///\sa DijkstraWizard |
---|
1285 | ///\sa Dijkstra |
---|
1286 | template<typename GR, typename LEN> |
---|
1287 | DijkstraWizard<DijkstraWizardBase<GR,LEN> > |
---|
1288 | dijkstra(const GR &digraph, const LEN &length) |
---|
1289 | { |
---|
1290 | return DijkstraWizard<DijkstraWizardBase<GR,LEN> >(digraph,length); |
---|
1291 | } |
---|
1292 | |
---|
1293 | } //END OF NAMESPACE LEMON |
---|
1294 | |
---|
1295 | #endif |
---|