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) 2003-2013 |
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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 | |
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21 | #include "test_tools.h" |
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22 | #include <lemon/smart_graph.h> |
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23 | #include <lemon/preflow.h> |
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24 | #include <lemon/edmonds_karp.h> |
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25 | #include <lemon/concepts/digraph.h> |
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26 | #include <lemon/concepts/maps.h> |
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27 | #include <lemon/lgf_reader.h> |
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28 | #include <lemon/elevator.h> |
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29 | #include <lemon/tolerance.h> |
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30 | |
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31 | using namespace lemon; |
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32 | |
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33 | char test_lgf[] = |
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34 | "@nodes\n" |
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35 | "label\n" |
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36 | "0\n" |
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37 | "1\n" |
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38 | "2\n" |
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39 | "3\n" |
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40 | "4\n" |
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41 | "5\n" |
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42 | "6\n" |
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43 | "7\n" |
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44 | "8\n" |
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45 | "9\n" |
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46 | "@arcs\n" |
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47 | " label capacity\n" |
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48 | "0 1 0 20\n" |
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49 | "0 2 1 0\n" |
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50 | "1 1 2 3\n" |
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51 | "1 2 3 8\n" |
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52 | "1 3 4 8\n" |
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53 | "2 5 5 5\n" |
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54 | "3 2 6 5\n" |
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55 | "3 5 7 5\n" |
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56 | "3 6 8 5\n" |
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57 | "4 3 9 3\n" |
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58 | "5 7 10 3\n" |
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59 | "5 6 11 10\n" |
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60 | "5 8 12 10\n" |
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61 | "6 8 13 8\n" |
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62 | "8 9 14 20\n" |
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63 | "8 1 15 5\n" |
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64 | "9 5 16 5\n" |
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65 | "@attributes\n" |
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66 | "source 1\n" |
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67 | "target 8\n"; |
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68 | |
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69 | char test_lgf_float[] = |
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70 | "@nodes\n" |
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71 | "label\n" |
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72 | "0\n" |
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73 | "1\n" |
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74 | "2\n" |
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75 | "3\n" |
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76 | "4\n" |
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77 | "5\n" |
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78 | "6\n" |
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79 | "7\n" |
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80 | "8\n" |
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81 | "9\n" |
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82 | "@arcs\n" |
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83 | " capacity\n" |
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84 | "0 1 0.1\n" |
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85 | "0 2 0.1\n" |
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86 | "0 3 0.1\n" |
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87 | "1 4 0.1\n" |
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88 | "2 4 0.1\n" |
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89 | "3 4 0.1\n" |
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90 | "4 5 0.3\n" |
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91 | "5 6 0.1\n" |
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92 | "5 7 0.1\n" |
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93 | "5 8 0.1\n" |
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94 | "6 9 0.1\n" |
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95 | "7 9 0.1\n" |
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96 | "8 9 0.1\n" |
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97 | "@attributes\n" |
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98 | "source 0\n" |
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99 | "target 9\n"; |
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100 | |
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101 | // Checks the general interface of a max flow algorithm |
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102 | template <typename GR, typename CAP> |
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103 | struct MaxFlowClassConcept |
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104 | { |
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105 | |
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106 | template <typename MF> |
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107 | struct Constraints { |
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108 | |
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109 | typedef typename GR::Node Node; |
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110 | typedef typename GR::Arc Arc; |
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111 | typedef typename CAP::Value Value; |
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112 | typedef concepts::ReadWriteMap<Arc, Value> FlowMap; |
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113 | typedef concepts::WriteMap<Node, bool> CutMap; |
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114 | |
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115 | GR g; |
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116 | Node n; |
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117 | Arc e; |
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118 | CAP cap; |
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119 | FlowMap flow; |
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120 | CutMap cut; |
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121 | Value v; |
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122 | bool b; |
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123 | |
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124 | void constraints() { |
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125 | checkConcept<concepts::Digraph, GR>(); |
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126 | |
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127 | const Constraints& me = *this; |
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128 | |
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129 | typedef typename MF |
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130 | ::template SetFlowMap<FlowMap> |
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131 | ::Create MaxFlowType; |
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132 | typedef typename MF::Create MaxFlowType2; |
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133 | MaxFlowType max_flow(me.g, me.cap, me.n, me.n); |
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134 | const MaxFlowType& const_max_flow = max_flow; |
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135 | |
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136 | max_flow |
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137 | .capacityMap(cap) |
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138 | .flowMap(flow) |
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139 | .source(n) |
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140 | .target(n); |
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141 | |
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142 | typename MaxFlowType::Tolerance tol = const_max_flow.tolerance(); |
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143 | max_flow.tolerance(tol); |
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144 | |
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145 | max_flow.init(); |
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146 | max_flow.init(cap); |
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147 | max_flow.run(); |
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148 | |
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149 | v = const_max_flow.flowValue(); |
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150 | v = const_max_flow.flow(e); |
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151 | const FlowMap& fm = const_max_flow.flowMap(); |
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152 | |
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153 | b = const_max_flow.minCut(n); |
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154 | const_max_flow.minCutMap(cut); |
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155 | |
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156 | ::lemon::ignore_unused_variable_warning(fm); |
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157 | } |
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158 | |
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159 | }; |
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160 | |
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161 | }; |
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162 | |
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163 | // Checks the specific parts of Preflow's interface |
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164 | void checkPreflowCompile() |
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165 | { |
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166 | typedef int Value; |
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167 | typedef concepts::Digraph Digraph; |
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168 | typedef concepts::ReadMap<Digraph::Arc, Value> CapMap; |
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169 | typedef Elevator<Digraph, Digraph::Node> Elev; |
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170 | typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev; |
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171 | |
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172 | Digraph g; |
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173 | Digraph::Node n; |
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174 | CapMap cap; |
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175 | |
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176 | typedef Preflow<Digraph, CapMap> |
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177 | ::SetElevator<Elev> |
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178 | ::SetStandardElevator<LinkedElev> |
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179 | ::Create PreflowType; |
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180 | PreflowType preflow_test(g, cap, n, n); |
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181 | const PreflowType& const_preflow_test = preflow_test; |
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182 | |
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183 | const PreflowType::Elevator& elev = const_preflow_test.elevator(); |
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184 | preflow_test.elevator(const_cast<PreflowType::Elevator&>(elev)); |
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185 | |
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186 | bool b = preflow_test.init(cap); |
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187 | preflow_test.startFirstPhase(); |
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188 | preflow_test.startSecondPhase(); |
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189 | preflow_test.runMinCut(); |
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190 | |
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191 | ::lemon::ignore_unused_variable_warning(b); |
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192 | } |
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193 | |
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194 | // Checks the specific parts of EdmondsKarp's interface |
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195 | void checkEdmondsKarpCompile() |
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196 | { |
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197 | typedef int Value; |
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198 | typedef concepts::Digraph Digraph; |
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199 | typedef concepts::ReadMap<Digraph::Arc, Value> CapMap; |
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200 | |
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201 | Digraph g; |
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202 | Digraph::Node n; |
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203 | CapMap cap; |
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204 | |
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205 | EdmondsKarp<Digraph, CapMap> ek_test(g, cap, n, n); |
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206 | |
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207 | ek_test.init(cap); |
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208 | bool b = ek_test.checkedInit(cap); |
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209 | b = ek_test.augment(); |
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210 | ek_test.start(); |
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211 | |
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212 | ::lemon::ignore_unused_variable_warning(b); |
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213 | } |
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214 | |
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215 | |
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216 | template <typename T> |
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217 | T cutValue(const SmartDigraph& g, |
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218 | const SmartDigraph::NodeMap<bool>& cut, |
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219 | const SmartDigraph::ArcMap<T>& cap) { |
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220 | |
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221 | T c = 0; |
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222 | for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) { |
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223 | if (cut[g.source(e)] && !cut[g.target(e)]) c += cap[e]; |
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224 | } |
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225 | return c; |
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226 | } |
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227 | |
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228 | template <typename T> |
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229 | bool checkFlow(const SmartDigraph& g, |
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230 | const SmartDigraph::ArcMap<T>& flow, |
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231 | const SmartDigraph::ArcMap<T>& cap, |
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232 | SmartDigraph::Node s, SmartDigraph::Node t, |
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233 | const Tolerance<T>& tol) { |
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234 | |
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235 | for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) { |
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236 | if (tol.negative(flow[e]) || tol.less(cap[e], flow[e])) return false; |
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237 | } |
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238 | |
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239 | for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) { |
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240 | if (n == s || n == t) continue; |
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241 | T sum = 0; |
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242 | for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) { |
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243 | sum += flow[e]; |
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244 | } |
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245 | for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) { |
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246 | sum -= flow[e]; |
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247 | } |
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248 | if (tol.nonZero(sum)) return false; |
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249 | } |
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250 | return true; |
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251 | } |
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252 | |
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253 | void checkInitPreflow() |
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254 | { |
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255 | DIGRAPH_TYPEDEFS(SmartDigraph); |
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256 | |
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257 | SmartDigraph g; |
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258 | SmartDigraph::ArcMap<int> cap(g), iflow(g); |
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259 | Node s = g.addNode(); Node t = g.addNode(); |
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260 | Node n1 = g.addNode(); Node n2 = g.addNode(); |
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261 | Arc a; |
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262 | a = g.addArc(s, n1); cap[a] = 20; iflow[a] = 20; |
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263 | a = g.addArc(n1, n2); cap[a] = 10; iflow[a] = 0; |
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264 | a = g.addArc(n2, t); cap[a] = 20; iflow[a] = 0; |
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265 | |
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266 | Preflow<SmartDigraph> pre(g, cap, s, t); |
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267 | pre.init(iflow); |
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268 | pre.startFirstPhase(); |
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269 | |
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270 | check(pre.flowValue() == 10, "Incorrect max flow value."); |
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271 | check(pre.minCut(s), "Wrong min cut (Node s)."); |
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272 | check(pre.minCut(n1), "Wrong min cut (Node n1)."); |
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273 | check(!pre.minCut(n2), "Wrong min cut (Node n2)."); |
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274 | check(!pre.minCut(t), "Wrong min cut (Node t)."); |
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275 | } |
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276 | |
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277 | template <typename MF, typename SF> |
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278 | void checkMaxFlowAlg(const char *input_lgf, typename MF::Value expected) { |
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279 | typedef SmartDigraph Digraph; |
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280 | DIGRAPH_TYPEDEFS(Digraph); |
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281 | |
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282 | typedef typename MF::Value Value; |
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283 | typedef Digraph::ArcMap<Value> CapMap; |
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284 | typedef CapMap FlowMap; |
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285 | typedef BoolNodeMap CutMap; |
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286 | |
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287 | Tolerance<Value> tol; |
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288 | |
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289 | Digraph g; |
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290 | Node s, t; |
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291 | CapMap cap(g); |
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292 | std::istringstream input(input_lgf); |
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293 | DigraphReader<Digraph>(g, input) |
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294 | .arcMap("capacity", cap) |
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295 | .node("source", s) |
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296 | .node("target", t) |
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297 | .run(); |
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298 | |
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299 | MF max_flow(g, cap, s, t); |
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300 | max_flow.run(); |
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301 | |
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302 | check(!tol.different(expected, max_flow.flowValue()), |
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303 | "Incorrect max flow value."); |
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304 | check(checkFlow(g, max_flow.flowMap(), cap, s, t, tol), |
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305 | "The flow is not feasible."); |
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306 | |
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307 | CutMap min_cut(g); |
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308 | max_flow.minCutMap(min_cut); |
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309 | Value min_cut_value = cutValue(g, min_cut, cap); |
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310 | |
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311 | check(!tol.different(expected, min_cut_value), |
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312 | "Incorrect min cut value."); |
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313 | |
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314 | FlowMap flow(g); |
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315 | for (ArcIt e(g); e != INVALID; ++e) flow[e] = 13 * max_flow.flowMap()[e]; |
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316 | for (ArcIt e(g); e != INVALID; ++e) cap[e] = 17 * cap[e]; |
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317 | max_flow.init(flow); |
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318 | |
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319 | SF::startFirstPhase(max_flow); // start first phase of the algorithm |
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320 | |
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321 | CutMap min_cut1(g); |
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322 | max_flow.minCutMap(min_cut1); |
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323 | min_cut_value = cutValue(g, min_cut1, cap); |
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324 | |
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325 | check(!tol.different(17 * expected, max_flow.flowValue()), |
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326 | "Incorrect max flow value."); |
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327 | check(!tol.different(17 * expected, min_cut_value), |
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328 | "Incorrect min cut value."); |
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329 | |
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330 | SF::startSecondPhase(max_flow); // start second phase of the algorithm |
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331 | |
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332 | check(checkFlow(g, max_flow.flowMap(), cap, s, t, tol), |
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333 | "The flow is not feasible."); |
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334 | |
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335 | CutMap min_cut2(g); |
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336 | max_flow.minCutMap(min_cut2); |
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337 | min_cut_value = cutValue(g, min_cut2, cap); |
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338 | |
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339 | check(!tol.different(17 * expected, max_flow.flowValue()), |
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340 | "Incorrect max flow value."); |
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341 | check(!tol.different(17 * expected, min_cut_value), |
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342 | "Incorrect min cut value."); |
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343 | |
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344 | max_flow.flowMap(flow); |
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345 | |
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346 | NodeIt tmp1(g, s); |
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347 | ++tmp1; |
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348 | if (tmp1 != INVALID) s = tmp1; |
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349 | |
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350 | NodeIt tmp2(g, t); |
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351 | ++tmp2; |
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352 | if (tmp2 != INVALID) t = tmp2; |
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353 | |
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354 | max_flow.source(s); |
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355 | max_flow.target(t); |
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356 | |
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357 | max_flow.run(); |
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358 | |
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359 | CutMap min_cut3(g); |
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360 | max_flow.minCutMap(min_cut3); |
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361 | min_cut_value = cutValue(g, min_cut3, cap); |
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362 | |
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363 | check(!tol.different(max_flow.flowValue(), min_cut_value), |
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364 | "The max flow value or the min cut value is wrong."); |
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365 | } |
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366 | |
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367 | // Struct for calling start functions of a general max flow algorithm |
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368 | template <typename MF> |
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369 | struct GeneralStartFunctions { |
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370 | |
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371 | static void startFirstPhase(MF& mf) { |
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372 | mf.start(); |
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373 | } |
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374 | |
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375 | static void startSecondPhase(MF& mf) { |
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376 | ::lemon::ignore_unused_variable_warning(mf); |
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377 | } |
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378 | |
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379 | }; |
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380 | |
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381 | // Struct for calling start functions of Preflow |
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382 | template <typename MF> |
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383 | struct PreflowStartFunctions { |
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384 | |
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385 | static void startFirstPhase(MF& mf) { |
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386 | mf.startFirstPhase(); |
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387 | } |
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388 | |
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389 | static void startSecondPhase(MF& mf) { |
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390 | mf.startSecondPhase(); |
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391 | } |
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392 | |
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393 | }; |
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394 | |
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395 | int main() { |
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396 | |
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397 | typedef concepts::Digraph GR; |
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398 | typedef concepts::ReadMap<GR::Arc, int> CM1; |
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399 | typedef concepts::ReadMap<GR::Arc, double> CM2; |
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400 | |
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401 | // Check the interface of Preflow |
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402 | checkConcept< MaxFlowClassConcept<GR, CM1>, |
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403 | Preflow<GR, CM1> >(); |
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404 | checkConcept< MaxFlowClassConcept<GR, CM2>, |
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405 | Preflow<GR, CM2> >(); |
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406 | |
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407 | // Check the interface of EdmondsKarp |
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408 | checkConcept< MaxFlowClassConcept<GR, CM1>, |
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409 | EdmondsKarp<GR, CM1> >(); |
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410 | checkConcept< MaxFlowClassConcept<GR, CM2>, |
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411 | EdmondsKarp<GR, CM2> >(); |
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412 | |
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413 | // Check Preflow |
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414 | typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<int> > PType1; |
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415 | typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<float> > PType2; |
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416 | typedef Preflow<SmartDigraph, SmartDigraph::ArcMap<double> > PType3; |
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417 | |
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418 | checkMaxFlowAlg<PType1, PreflowStartFunctions<PType1> >(test_lgf, 13); |
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419 | checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >(test_lgf, 13); |
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420 | checkMaxFlowAlg<PType3, PreflowStartFunctions<PType3> >(test_lgf, 13); |
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421 | |
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422 | checkMaxFlowAlg<PType2, PreflowStartFunctions<PType2> >(test_lgf_float, 0.3f); |
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423 | checkMaxFlowAlg<PType3, PreflowStartFunctions<PType3> >(test_lgf_float, 0.3); |
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424 | |
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425 | checkInitPreflow(); |
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426 | |
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427 | // Check EdmondsKarp |
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428 | typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<int> > EKType1; |
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429 | typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<float> > EKType2; |
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430 | typedef EdmondsKarp<SmartDigraph, SmartDigraph::ArcMap<double> > EKType3; |
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431 | |
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432 | checkMaxFlowAlg<EKType1, GeneralStartFunctions<EKType1> >(test_lgf, 13); |
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433 | checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >(test_lgf, 13); |
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434 | checkMaxFlowAlg<EKType3, GeneralStartFunctions<EKType3> >(test_lgf, 13); |
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435 | |
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436 | checkMaxFlowAlg<EKType2, GeneralStartFunctions<EKType2> >(test_lgf_float, 0.3f); |
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437 | checkMaxFlowAlg<EKType3, GeneralStartFunctions<EKType3> >(test_lgf_float, 0.3); |
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438 | |
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439 | return 0; |
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440 | } |
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