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 | #include <iostream> |
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20 | #include <fstream> |
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21 | |
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22 | #include <lemon/smart_graph.h> |
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23 | #include <lemon/dijkstra.h> |
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24 | #include <lemon/maps.h> |
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25 | #include <lemon/dim2.h> |
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26 | #include <lemon/graph_reader.h> |
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27 | |
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28 | #include <lemon/time_measure.h> |
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29 | |
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30 | #include <cmath> |
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31 | |
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32 | /// \ingroup demos |
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33 | /// \file |
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34 | /// \brief Minimal route on a planar graph with eucledian distances. |
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35 | /// |
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36 | /// Minimal route on a planar graph with eucledian distances. |
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37 | /// |
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38 | /// \include min_route.cc |
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39 | |
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40 | |
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41 | using namespace lemon; |
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42 | |
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43 | template <typename CoordMap> |
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44 | class PotentialMap { |
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45 | public: |
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46 | typedef double Value; |
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47 | typedef typename CoordMap::Key Key; |
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48 | |
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49 | PotentialMap(const CoordMap& _coord, const dim2::Point<double>& _target) |
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50 | : coord(_coord), target(_target) {} |
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51 | |
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52 | double operator[](const Key& node) const { |
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53 | return std::sqrt((coord[node].x - target.x) * (coord[node].x - target.x) + |
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54 | (coord[node].y - target.y) * (coord[node].y - target.y)); |
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55 | } |
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56 | private: |
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57 | const CoordMap& coord; |
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58 | dim2::Point<double> target; |
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59 | }; |
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60 | |
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61 | template <typename Graph, typename LengthMap, typename PotentialMap> |
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62 | class ReducedLengthMap { |
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63 | public: |
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64 | typedef double Value; |
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65 | typedef typename LengthMap::Key Key; |
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66 | |
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67 | ReducedLengthMap(const Graph& _graph, const LengthMap& _length, |
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68 | const PotentialMap& _pot) |
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69 | : graph(_graph), length(_length), pot(_pot) {} |
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70 | |
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71 | Value operator[](const Key& edge) const { |
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72 | return length[edge] - (pot[graph.source(edge)] - pot[graph.target(edge)]); |
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73 | } |
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74 | |
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75 | private: |
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76 | const Graph& graph; |
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77 | const LengthMap& length; |
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78 | const PotentialMap& pot; |
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79 | }; |
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80 | |
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81 | int main() { |
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82 | typedef SmartGraph Graph; |
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83 | |
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84 | typedef Graph::Edge Edge; |
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85 | typedef Graph::Node Node; |
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86 | typedef Graph::EdgeIt EdgeIt; |
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87 | typedef Graph::NodeIt NodeIt; |
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88 | typedef Graph::EdgeMap<double> LengthMap; |
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89 | typedef Graph::NodeMap<dim2::Point<double> > CoordMap; |
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90 | |
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91 | SmartGraph graph; |
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92 | |
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93 | std::ifstream is("route.lgf"); |
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94 | GraphReader<Graph> reader(is, graph); |
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95 | |
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96 | CoordMap coord(graph); |
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97 | dim2::XMap<CoordMap> xcoord = xMap(coord); |
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98 | reader.readNodeMap("coordinates_x", xcoord); |
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99 | dim2::YMap<CoordMap> ycoord = yMap(coord); |
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100 | reader.readNodeMap("coordinates_y", ycoord); |
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101 | |
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102 | LengthMap length(graph); |
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103 | reader.readEdgeMap("length", length); |
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104 | |
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105 | Node source, target; |
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106 | reader.readNode("source", source); |
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107 | reader.readNode("target", target); |
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108 | |
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109 | reader.run(); |
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110 | |
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111 | { |
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112 | Timer timer; |
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113 | Dijkstra<Graph, LengthMap> dijkstra(graph, length); |
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114 | dijkstra.init(); |
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115 | dijkstra.addSource(source); |
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116 | dijkstra.start(target); |
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117 | |
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118 | std::cout << dijkstra.dist(target) << std::endl; |
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119 | std::cout << timer << std::endl; |
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120 | } |
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121 | { |
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122 | Timer timer; |
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123 | typedef PotentialMap<CoordMap> Potential; |
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124 | Potential potential(coord, coord[target]); |
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125 | |
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126 | typedef ReducedLengthMap<Graph, LengthMap, Potential> ReducedLength; |
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127 | ReducedLength reduced(graph, length, potential); |
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128 | |
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129 | Dijkstra<Graph, ReducedLength> dijkstra(graph, reduced); |
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130 | |
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131 | dijkstra.init(); |
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132 | dijkstra.addSource(source); |
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133 | dijkstra.start(target); |
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134 | |
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135 | std::cout << dijkstra.dist(target) + potential[source] << std::endl; |
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136 | std::cout << timer << std::endl; |
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137 | } |
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138 | |
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139 | return 0; |
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140 | } |
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