1 | /* -*- mode: C++; indent-tabs-mode: nil; -*- |
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2 | * |
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3 | * This file is a part of LEMON, a generic C++ optimization library. |
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4 | * |
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5 | * Copyright (C) 2003-2008 |
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6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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8 | * |
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9 | * Permission to use, modify and distribute this software is granted |
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10 | * provided that this copyright notice appears in all copies. For |
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11 | * precise terms see the accompanying LICENSE file. |
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12 | * |
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13 | * This software is provided "AS IS" with no warranty of any kind, |
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14 | * express or implied, and with no claim as to its suitability for any |
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15 | * purpose. |
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16 | * |
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17 | */ |
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18 | |
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19 | #ifndef LEMON_CIRCULATION_H |
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20 | #define LEMON_CIRCULATION_H |
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21 | |
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22 | #include <iostream> |
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23 | #include <queue> |
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24 | #include <lemon/tolerance.h> |
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25 | #include <lemon/elevator.h> |
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26 | |
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27 | ///\ingroup max_flow |
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28 | ///\file |
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29 | ///\brief Push-prelabel algorithm for finding a feasible circulation. |
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30 | /// |
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31 | namespace lemon { |
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32 | |
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33 | /// \brief Default traits class of Circulation class. |
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34 | /// |
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35 | /// Default traits class of Circulation class. |
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36 | /// \param _Graph Digraph type. |
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37 | /// \param _CapacityMap Type of capacity map. |
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38 | template <typename _Graph, typename _LCapMap, |
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39 | typename _UCapMap, typename _DeltaMap> |
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40 | struct CirculationDefaultTraits { |
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41 | |
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42 | /// \brief The digraph type the algorithm runs on. |
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43 | typedef _Graph Digraph; |
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44 | |
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45 | /// \brief The type of the map that stores the circulation lower |
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46 | /// bound. |
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47 | /// |
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48 | /// The type of the map that stores the circulation lower bound. |
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49 | /// It must meet the \ref concepts::ReadMap "ReadMap" concept. |
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50 | typedef _LCapMap LCapMap; |
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51 | |
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52 | /// \brief The type of the map that stores the circulation upper |
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53 | /// bound. |
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54 | /// |
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55 | /// The type of the map that stores the circulation upper bound. |
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56 | /// It must meet the \ref concepts::ReadMap "ReadMap" concept. |
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57 | typedef _UCapMap UCapMap; |
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58 | |
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59 | /// \brief The type of the map that stores the upper bound of |
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60 | /// node excess. |
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61 | /// |
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62 | /// The type of the map that stores the lower bound of node |
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63 | /// excess. It must meet the \ref concepts::ReadMap "ReadMap" |
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64 | /// concept. |
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65 | typedef _DeltaMap DeltaMap; |
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66 | |
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67 | /// \brief The type of the length of the arcs. |
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68 | typedef typename DeltaMap::Value Value; |
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69 | |
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70 | /// \brief The map type that stores the flow values. |
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71 | /// |
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72 | /// The map type that stores the flow values. |
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73 | /// It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept. |
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74 | typedef typename Digraph::template ArcMap<Value> FlowMap; |
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75 | |
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76 | /// \brief Instantiates a FlowMap. |
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77 | /// |
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78 | /// This function instantiates a \ref FlowMap. |
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79 | /// \param digraph The digraph, to which we would like to define |
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80 | /// the flow map. |
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81 | static FlowMap* createFlowMap(const Digraph& digraph) { |
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82 | return new FlowMap(digraph); |
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83 | } |
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84 | |
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85 | /// \brief The eleavator type used by Circulation algorithm. |
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86 | /// |
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87 | /// The elevator type used by Circulation algorithm. |
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88 | /// |
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89 | /// \sa Elevator |
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90 | /// \sa LinkedElevator |
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91 | typedef lemon::Elevator<Digraph, typename Digraph::Node> Elevator; |
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92 | |
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93 | /// \brief Instantiates an Elevator. |
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94 | /// |
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95 | /// This function instantiates a \ref Elevator. |
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96 | /// \param digraph The digraph, to which we would like to define |
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97 | /// the elevator. |
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98 | /// \param max_level The maximum level of the elevator. |
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99 | static Elevator* createElevator(const Digraph& digraph, int max_level) { |
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100 | return new Elevator(digraph, max_level); |
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101 | } |
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102 | |
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103 | /// \brief The tolerance used by the algorithm |
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104 | /// |
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105 | /// The tolerance used by the algorithm to handle inexact computation. |
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106 | typedef lemon::Tolerance<Value> Tolerance; |
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107 | |
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108 | }; |
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109 | |
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110 | ///Push-relabel algorithm for the Network Circulation Problem. |
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111 | |
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112 | /** |
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113 | \ingroup max_flow |
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114 | This class implements a push-relabel algorithm |
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115 | or the Network Circulation Problem. |
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116 | The exact formulation of this problem is the following. |
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117 | \f[\sum_{e\in\rho(v)}x(e)-\sum_{e\in\delta(v)}x(e)\leq |
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118 | -delta(v)\quad \forall v\in V \f] |
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119 | \f[ lo(e)\leq x(e) \leq up(e) \quad \forall e\in E \f] |
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120 | */ |
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121 | template<class _Graph, |
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122 | class _LCapMap=typename _Graph::template ArcMap<int>, |
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123 | class _UCapMap=_LCapMap, |
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124 | class _DeltaMap=typename _Graph::template NodeMap< |
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125 | typename _UCapMap::Value>, |
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126 | class _Traits=CirculationDefaultTraits<_Graph, _LCapMap, |
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127 | _UCapMap, _DeltaMap> > |
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128 | class Circulation { |
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129 | |
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130 | typedef _Traits Traits; |
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131 | typedef typename Traits::Digraph Digraph; |
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132 | TEMPLATE_DIGRAPH_TYPEDEFS(Digraph); |
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133 | |
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134 | typedef typename Traits::Value Value; |
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135 | |
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136 | typedef typename Traits::LCapMap LCapMap; |
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137 | typedef typename Traits::UCapMap UCapMap; |
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138 | typedef typename Traits::DeltaMap DeltaMap; |
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139 | typedef typename Traits::FlowMap FlowMap; |
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140 | typedef typename Traits::Elevator Elevator; |
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141 | typedef typename Traits::Tolerance Tolerance; |
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142 | |
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143 | typedef typename Digraph::template NodeMap<Value> ExcessMap; |
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144 | |
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145 | const Digraph &_g; |
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146 | int _node_num; |
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147 | |
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148 | const LCapMap *_lo; |
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149 | const UCapMap *_up; |
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150 | const DeltaMap *_delta; |
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151 | |
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152 | FlowMap *_flow; |
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153 | bool _local_flow; |
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154 | |
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155 | Elevator* _level; |
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156 | bool _local_level; |
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157 | |
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158 | ExcessMap* _excess; |
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159 | |
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160 | Tolerance _tol; |
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161 | int _el; |
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162 | |
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163 | public: |
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164 | |
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165 | typedef Circulation Create; |
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166 | |
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167 | ///\name Named template parameters |
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168 | |
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169 | ///@{ |
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170 | |
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171 | template <typename _FlowMap> |
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172 | struct SetFlowMapTraits : public Traits { |
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173 | typedef _FlowMap FlowMap; |
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174 | static FlowMap *createFlowMap(const Digraph&) { |
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175 | LEMON_ASSERT(false, "FlowMap is not initialized"); |
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176 | return 0; // ignore warnings |
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177 | } |
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178 | }; |
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179 | |
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180 | /// \brief \ref named-templ-param "Named parameter" for setting |
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181 | /// FlowMap type |
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182 | /// |
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183 | /// \ref named-templ-param "Named parameter" for setting FlowMap |
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184 | /// type |
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185 | template <typename _FlowMap> |
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186 | struct SetFlowMap |
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187 | : public Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
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188 | SetFlowMapTraits<_FlowMap> > { |
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189 | typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
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190 | SetFlowMapTraits<_FlowMap> > Create; |
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191 | }; |
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192 | |
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193 | template <typename _Elevator> |
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194 | struct SetElevatorTraits : public Traits { |
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195 | typedef _Elevator Elevator; |
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196 | static Elevator *createElevator(const Digraph&, int) { |
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197 | LEMON_ASSERT(false, "Elevator is not initialized"); |
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198 | return 0; // ignore warnings |
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199 | } |
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200 | }; |
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201 | |
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202 | /// \brief \ref named-templ-param "Named parameter" for setting |
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203 | /// Elevator type |
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204 | /// |
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205 | /// \ref named-templ-param "Named parameter" for setting Elevator |
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206 | /// type |
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207 | template <typename _Elevator> |
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208 | struct SetElevator |
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209 | : public Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
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210 | SetElevatorTraits<_Elevator> > { |
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211 | typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
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212 | SetElevatorTraits<_Elevator> > Create; |
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213 | }; |
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214 | |
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215 | template <typename _Elevator> |
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216 | struct SetStandardElevatorTraits : public Traits { |
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217 | typedef _Elevator Elevator; |
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218 | static Elevator *createElevator(const Digraph& digraph, int max_level) { |
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219 | return new Elevator(digraph, max_level); |
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220 | } |
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221 | }; |
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222 | |
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223 | /// \brief \ref named-templ-param "Named parameter" for setting |
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224 | /// Elevator type |
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225 | /// |
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226 | /// \ref named-templ-param "Named parameter" for setting Elevator |
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227 | /// type. The Elevator should be standard constructor interface, ie. |
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228 | /// the digraph and the maximum level should be passed to it. |
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229 | template <typename _Elevator> |
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230 | struct SetStandardElevator |
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231 | : public Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
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232 | SetStandardElevatorTraits<_Elevator> > { |
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233 | typedef Circulation<Digraph, LCapMap, UCapMap, DeltaMap, |
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234 | SetStandardElevatorTraits<_Elevator> > Create; |
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235 | }; |
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236 | |
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237 | /// @} |
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238 | |
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239 | protected: |
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240 | |
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241 | Circulation() {} |
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242 | |
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243 | public: |
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244 | |
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245 | /// The constructor of the class. |
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246 | |
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247 | /// The constructor of the class. |
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248 | /// \param g The digraph the algorithm runs on. |
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249 | /// \param lo The lower bound capacity of the arcs. |
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250 | /// \param up The upper bound capacity of the arcs. |
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251 | /// \param delta The lower bound on node excess. |
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252 | Circulation(const Digraph &g,const LCapMap &lo, |
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253 | const UCapMap &up,const DeltaMap &delta) |
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254 | : _g(g), _node_num(), |
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255 | _lo(&lo),_up(&up),_delta(&delta),_flow(0),_local_flow(false), |
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256 | _level(0), _local_level(false), _excess(0), _el() {} |
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257 | |
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258 | /// Destrcutor. |
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259 | ~Circulation() { |
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260 | destroyStructures(); |
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261 | } |
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262 | |
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263 | private: |
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264 | |
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265 | void createStructures() { |
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266 | _node_num = _el = countNodes(_g); |
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267 | |
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268 | if (!_flow) { |
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269 | _flow = Traits::createFlowMap(_g); |
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270 | _local_flow = true; |
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271 | } |
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272 | if (!_level) { |
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273 | _level = Traits::createElevator(_g, _node_num); |
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274 | _local_level = true; |
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275 | } |
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276 | if (!_excess) { |
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277 | _excess = new ExcessMap(_g); |
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278 | } |
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279 | } |
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280 | |
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281 | void destroyStructures() { |
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282 | if (_local_flow) { |
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283 | delete _flow; |
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284 | } |
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285 | if (_local_level) { |
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286 | delete _level; |
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287 | } |
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288 | if (_excess) { |
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289 | delete _excess; |
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290 | } |
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291 | } |
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292 | |
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293 | public: |
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294 | |
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295 | /// Sets the lower bound capacity map. |
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296 | |
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297 | /// Sets the lower bound capacity map. |
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298 | /// \return \c (*this) |
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299 | Circulation& lowerCapMap(const LCapMap& map) { |
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300 | _lo = ↦ |
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301 | return *this; |
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302 | } |
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303 | |
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304 | /// Sets the upper bound capacity map. |
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305 | |
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306 | /// Sets the upper bound capacity map. |
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307 | /// \return \c (*this) |
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308 | Circulation& upperCapMap(const LCapMap& map) { |
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309 | _up = ↦ |
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310 | return *this; |
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311 | } |
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312 | |
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313 | /// Sets the lower bound map on excess. |
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314 | |
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315 | /// Sets the lower bound map on excess. |
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316 | /// \return \c (*this) |
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317 | Circulation& deltaMap(const DeltaMap& map) { |
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318 | _delta = ↦ |
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319 | return *this; |
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320 | } |
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321 | |
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322 | /// Sets the flow map. |
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323 | |
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324 | /// Sets the flow map. |
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325 | /// \return \c (*this) |
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326 | Circulation& flowMap(FlowMap& map) { |
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327 | if (_local_flow) { |
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328 | delete _flow; |
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329 | _local_flow = false; |
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330 | } |
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331 | _flow = ↦ |
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332 | return *this; |
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333 | } |
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334 | |
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335 | /// Returns the flow map. |
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336 | |
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337 | /// \return The flow map. |
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338 | /// |
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339 | const FlowMap& flowMap() { |
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340 | return *_flow; |
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341 | } |
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342 | |
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343 | /// Sets the elevator. |
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344 | |
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345 | /// Sets the elevator. |
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346 | /// \return \c (*this) |
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347 | Circulation& elevator(Elevator& elevator) { |
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348 | if (_local_level) { |
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349 | delete _level; |
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350 | _local_level = false; |
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351 | } |
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352 | _level = &elevator; |
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353 | return *this; |
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354 | } |
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355 | |
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356 | /// Returns the elevator. |
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357 | |
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358 | /// \return The elevator. |
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359 | /// |
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360 | const Elevator& elevator() { |
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361 | return *_level; |
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362 | } |
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363 | |
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364 | /// Sets the tolerance used by algorithm. |
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365 | |
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366 | /// Sets the tolerance used by algorithm. |
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367 | /// |
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368 | Circulation& tolerance(const Tolerance& tolerance) const { |
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369 | _tol = tolerance; |
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370 | return *this; |
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371 | } |
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372 | |
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373 | /// Returns the tolerance used by algorithm. |
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374 | |
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375 | /// Returns the tolerance used by algorithm. |
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376 | /// |
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377 | const Tolerance& tolerance() const { |
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378 | return tolerance; |
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379 | } |
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380 | |
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381 | /// \name Execution control |
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382 | /// The simplest way to execute the algorithm is to use one of the |
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383 | /// member functions called \c run(). |
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384 | /// \n |
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385 | /// If you need more control on initial solution or execution then |
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386 | /// you have to call one \ref init() function and then the start() |
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387 | /// function. |
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388 | |
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389 | ///@{ |
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390 | |
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391 | /// Initializes the internal data structures. |
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392 | |
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393 | /// Initializes the internal data structures. This function sets |
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394 | /// all flow values to the lower bound. |
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395 | /// \return This function returns false if the initialization |
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396 | /// process found a barrier. |
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397 | void init() |
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398 | { |
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399 | createStructures(); |
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400 | |
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401 | for(NodeIt n(_g);n!=INVALID;++n) { |
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402 | _excess->set(n, (*_delta)[n]); |
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403 | } |
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404 | |
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405 | for (ArcIt e(_g);e!=INVALID;++e) { |
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406 | _flow->set(e, (*_lo)[e]); |
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407 | _excess->set(_g.target(e), (*_excess)[_g.target(e)] + (*_flow)[e]); |
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408 | _excess->set(_g.source(e), (*_excess)[_g.source(e)] - (*_flow)[e]); |
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409 | } |
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410 | |
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411 | // global relabeling tested, but in general case it provides |
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412 | // worse performance for random digraphs |
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413 | _level->initStart(); |
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414 | for(NodeIt n(_g);n!=INVALID;++n) |
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415 | _level->initAddItem(n); |
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416 | _level->initFinish(); |
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417 | for(NodeIt n(_g);n!=INVALID;++n) |
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418 | if(_tol.positive((*_excess)[n])) |
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419 | _level->activate(n); |
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420 | } |
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421 | |
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422 | /// Initializes the internal data structures. |
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423 | |
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424 | /// Initializes the internal data structures. This functions uses |
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425 | /// greedy approach to construct the initial solution. |
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426 | void greedyInit() |
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427 | { |
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428 | createStructures(); |
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429 | |
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430 | for(NodeIt n(_g);n!=INVALID;++n) { |
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431 | _excess->set(n, (*_delta)[n]); |
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432 | } |
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433 | |
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434 | for (ArcIt e(_g);e!=INVALID;++e) { |
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435 | if (!_tol.positive((*_excess)[_g.target(e)] + (*_up)[e])) { |
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436 | _flow->set(e, (*_up)[e]); |
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437 | _excess->set(_g.target(e), (*_excess)[_g.target(e)] + (*_up)[e]); |
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438 | _excess->set(_g.source(e), (*_excess)[_g.source(e)] - (*_up)[e]); |
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439 | } else if (_tol.positive((*_excess)[_g.target(e)] + (*_lo)[e])) { |
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440 | _flow->set(e, (*_lo)[e]); |
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441 | _excess->set(_g.target(e), (*_excess)[_g.target(e)] + (*_lo)[e]); |
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442 | _excess->set(_g.source(e), (*_excess)[_g.source(e)] - (*_lo)[e]); |
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443 | } else { |
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444 | Value fc = -(*_excess)[_g.target(e)]; |
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445 | _flow->set(e, fc); |
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446 | _excess->set(_g.target(e), 0); |
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447 | _excess->set(_g.source(e), (*_excess)[_g.source(e)] - fc); |
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448 | } |
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449 | } |
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450 | |
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451 | _level->initStart(); |
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452 | for(NodeIt n(_g);n!=INVALID;++n) |
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453 | _level->initAddItem(n); |
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454 | _level->initFinish(); |
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455 | for(NodeIt n(_g);n!=INVALID;++n) |
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456 | if(_tol.positive((*_excess)[n])) |
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457 | _level->activate(n); |
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458 | } |
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459 | |
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460 | ///Starts the algorithm |
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461 | |
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462 | ///This function starts the algorithm. |
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463 | ///\return This function returns true if it found a feasible circulation. |
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464 | /// |
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465 | ///\sa barrier() |
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466 | bool start() |
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467 | { |
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468 | |
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469 | Node act; |
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470 | Node bact=INVALID; |
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471 | Node last_activated=INVALID; |
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472 | while((act=_level->highestActive())!=INVALID) { |
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473 | int actlevel=(*_level)[act]; |
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474 | int mlevel=_node_num; |
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475 | Value exc=(*_excess)[act]; |
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476 | |
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477 | for(OutArcIt e(_g,act);e!=INVALID; ++e) { |
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478 | Node v = _g.target(e); |
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479 | Value fc=(*_up)[e]-(*_flow)[e]; |
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480 | if(!_tol.positive(fc)) continue; |
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481 | if((*_level)[v]<actlevel) { |
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482 | if(!_tol.less(fc, exc)) { |
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483 | _flow->set(e, (*_flow)[e] + exc); |
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484 | _excess->set(v, (*_excess)[v] + exc); |
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485 | if(!_level->active(v) && _tol.positive((*_excess)[v])) |
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486 | _level->activate(v); |
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487 | _excess->set(act,0); |
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488 | _level->deactivate(act); |
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489 | goto next_l; |
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490 | } |
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491 | else { |
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492 | _flow->set(e, (*_up)[e]); |
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493 | _excess->set(v, (*_excess)[v] + fc); |
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494 | if(!_level->active(v) && _tol.positive((*_excess)[v])) |
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495 | _level->activate(v); |
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496 | exc-=fc; |
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497 | } |
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498 | } |
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499 | else if((*_level)[v]<mlevel) mlevel=(*_level)[v]; |
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500 | } |
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501 | for(InArcIt e(_g,act);e!=INVALID; ++e) { |
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502 | Node v = _g.source(e); |
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503 | Value fc=(*_flow)[e]-(*_lo)[e]; |
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504 | if(!_tol.positive(fc)) continue; |
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505 | if((*_level)[v]<actlevel) { |
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506 | if(!_tol.less(fc, exc)) { |
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507 | _flow->set(e, (*_flow)[e] - exc); |
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508 | _excess->set(v, (*_excess)[v] + exc); |
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509 | if(!_level->active(v) && _tol.positive((*_excess)[v])) |
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510 | _level->activate(v); |
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511 | _excess->set(act,0); |
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512 | _level->deactivate(act); |
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513 | goto next_l; |
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514 | } |
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515 | else { |
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516 | _flow->set(e, (*_lo)[e]); |
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517 | _excess->set(v, (*_excess)[v] + fc); |
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518 | if(!_level->active(v) && _tol.positive((*_excess)[v])) |
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519 | _level->activate(v); |
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520 | exc-=fc; |
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521 | } |
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522 | } |
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523 | else if((*_level)[v]<mlevel) mlevel=(*_level)[v]; |
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524 | } |
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525 | |
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526 | _excess->set(act, exc); |
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527 | if(!_tol.positive(exc)) _level->deactivate(act); |
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528 | else if(mlevel==_node_num) { |
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529 | _level->liftHighestActiveToTop(); |
---|
530 | _el = _node_num; |
---|
531 | return false; |
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532 | } |
---|
533 | else { |
---|
534 | _level->liftHighestActive(mlevel+1); |
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535 | if(_level->onLevel(actlevel)==0) { |
---|
536 | _el = actlevel; |
---|
537 | return false; |
---|
538 | } |
---|
539 | } |
---|
540 | next_l: |
---|
541 | ; |
---|
542 | } |
---|
543 | return true; |
---|
544 | } |
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545 | |
---|
546 | /// Runs the circulation algorithm. |
---|
547 | |
---|
548 | /// Runs the circulation algorithm. |
---|
549 | /// \note fc.run() is just a shortcut of the following code. |
---|
550 | /// \code |
---|
551 | /// fc.greedyInit(); |
---|
552 | /// return fc.start(); |
---|
553 | /// \endcode |
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554 | bool run() { |
---|
555 | greedyInit(); |
---|
556 | return start(); |
---|
557 | } |
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558 | |
---|
559 | /// @} |
---|
560 | |
---|
561 | /// \name Query Functions |
---|
562 | /// The result of the %Circulation algorithm can be obtained using |
---|
563 | /// these functions. |
---|
564 | /// \n |
---|
565 | /// Before the use of these functions, |
---|
566 | /// either run() or start() must be called. |
---|
567 | |
---|
568 | ///@{ |
---|
569 | |
---|
570 | /** |
---|
571 | \brief Returns a barrier |
---|
572 | |
---|
573 | Barrier is a set \e B of nodes for which |
---|
574 | \f[ \sum_{v\in B}-delta(v)< |
---|
575 | \sum_{e\in\rho(B)}lo(e)-\sum_{e\in\delta(B)}up(e) \f] |
---|
576 | holds. The existence of a set with this property prooves that a feasible |
---|
577 | flow cannot exists. |
---|
578 | \sa checkBarrier() |
---|
579 | \sa run() |
---|
580 | */ |
---|
581 | template<class GT> |
---|
582 | void barrierMap(GT &bar) |
---|
583 | { |
---|
584 | for(NodeIt n(_g);n!=INVALID;++n) |
---|
585 | bar.set(n, (*_level)[n] >= _el); |
---|
586 | } |
---|
587 | |
---|
588 | ///Returns true if the node is in the barrier |
---|
589 | |
---|
590 | ///Returns true if the node is in the barrier |
---|
591 | ///\sa barrierMap() |
---|
592 | bool barrier(const Node& node) |
---|
593 | { |
---|
594 | return (*_level)[node] >= _el; |
---|
595 | } |
---|
596 | |
---|
597 | /// \brief Returns the flow on the arc. |
---|
598 | /// |
---|
599 | /// Sets the \c flowMap to the flow on the arcs. This method can |
---|
600 | /// be called after the second phase of algorithm. |
---|
601 | Value flow(const Arc& arc) const { |
---|
602 | return (*_flow)[arc]; |
---|
603 | } |
---|
604 | |
---|
605 | /// @} |
---|
606 | |
---|
607 | /// \name Checker Functions |
---|
608 | /// The feasibility of the results can be checked using |
---|
609 | /// these functions. |
---|
610 | /// \n |
---|
611 | /// Before the use of these functions, |
---|
612 | /// either run() or start() must be called. |
---|
613 | |
---|
614 | ///@{ |
---|
615 | |
---|
616 | ///Check if the \c flow is a feasible circulation |
---|
617 | bool checkFlow() { |
---|
618 | for(ArcIt e(_g);e!=INVALID;++e) |
---|
619 | if((*_flow)[e]<(*_lo)[e]||(*_flow)[e]>(*_up)[e]) return false; |
---|
620 | for(NodeIt n(_g);n!=INVALID;++n) |
---|
621 | { |
---|
622 | Value dif=-(*_delta)[n]; |
---|
623 | for(InArcIt e(_g,n);e!=INVALID;++e) dif-=(*_flow)[e]; |
---|
624 | for(OutArcIt e(_g,n);e!=INVALID;++e) dif+=(*_flow)[e]; |
---|
625 | if(_tol.negative(dif)) return false; |
---|
626 | } |
---|
627 | return true; |
---|
628 | } |
---|
629 | |
---|
630 | ///Check whether or not the last execution provides a barrier |
---|
631 | |
---|
632 | ///Check whether or not the last execution provides a barrier |
---|
633 | ///\sa barrier() |
---|
634 | bool checkBarrier() |
---|
635 | { |
---|
636 | Value delta=0; |
---|
637 | for(NodeIt n(_g);n!=INVALID;++n) |
---|
638 | if(barrier(n)) |
---|
639 | delta-=(*_delta)[n]; |
---|
640 | for(ArcIt e(_g);e!=INVALID;++e) |
---|
641 | { |
---|
642 | Node s=_g.source(e); |
---|
643 | Node t=_g.target(e); |
---|
644 | if(barrier(s)&&!barrier(t)) delta+=(*_up)[e]; |
---|
645 | else if(barrier(t)&&!barrier(s)) delta-=(*_lo)[e]; |
---|
646 | } |
---|
647 | return _tol.negative(delta); |
---|
648 | } |
---|
649 | |
---|
650 | /// @} |
---|
651 | |
---|
652 | }; |
---|
653 | |
---|
654 | } |
---|
655 | |
---|
656 | #endif |
---|