[389] | 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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[440] | 5 | * Copyright (C) 2003-2009 |
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[389] | 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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[423] | 19 | #include <iostream> |
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[389] | 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/concepts/digraph.h> |
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| 25 | #include <lemon/concepts/maps.h> |
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| 26 | #include <lemon/lgf_reader.h> |
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[394] | 27 | #include <lemon/elevator.h> |
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[389] | 28 | |
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| 29 | using namespace lemon; |
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| 30 | |
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[423] | 31 | char test_lgf[] = |
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| 32 | "@nodes\n" |
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| 33 | "label\n" |
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| 34 | "0\n" |
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| 35 | "1\n" |
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| 36 | "2\n" |
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| 37 | "3\n" |
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| 38 | "4\n" |
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| 39 | "5\n" |
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| 40 | "6\n" |
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| 41 | "7\n" |
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| 42 | "8\n" |
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| 43 | "9\n" |
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| 44 | "@arcs\n" |
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| 45 | " label capacity\n" |
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| 46 | "0 1 0 20\n" |
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| 47 | "0 2 1 0\n" |
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| 48 | "1 1 2 3\n" |
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| 49 | "1 2 3 8\n" |
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| 50 | "1 3 4 8\n" |
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| 51 | "2 5 5 5\n" |
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| 52 | "3 2 6 5\n" |
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| 53 | "3 5 7 5\n" |
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| 54 | "3 6 8 5\n" |
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| 55 | "4 3 9 3\n" |
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| 56 | "5 7 10 3\n" |
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| 57 | "5 6 11 10\n" |
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| 58 | "5 8 12 10\n" |
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| 59 | "6 8 13 8\n" |
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| 60 | "8 9 14 20\n" |
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| 61 | "8 1 15 5\n" |
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| 62 | "9 5 16 5\n" |
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| 63 | "@attributes\n" |
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| 64 | "source 1\n" |
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| 65 | "target 8\n"; |
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| 66 | |
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[394] | 67 | void checkPreflowCompile() |
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[389] | 68 | { |
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| 69 | typedef int VType; |
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| 70 | typedef concepts::Digraph Digraph; |
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| 71 | |
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| 72 | typedef Digraph::Node Node; |
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| 73 | typedef Digraph::Arc Arc; |
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| 74 | typedef concepts::ReadMap<Arc,VType> CapMap; |
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| 75 | typedef concepts::ReadWriteMap<Arc,VType> FlowMap; |
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| 76 | typedef concepts::WriteMap<Node,bool> CutMap; |
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| 77 | |
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[394] | 78 | typedef Elevator<Digraph, Digraph::Node> Elev; |
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| 79 | typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev; |
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| 80 | |
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[389] | 81 | Digraph g; |
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| 82 | Node n; |
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| 83 | Arc e; |
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| 84 | CapMap cap; |
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| 85 | FlowMap flow; |
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| 86 | CutMap cut; |
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[585] | 87 | VType v; |
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| 88 | bool b; |
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[389] | 89 | |
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[585] | 90 | typedef Preflow<Digraph, CapMap> |
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| 91 | ::SetFlowMap<FlowMap> |
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| 92 | ::SetElevator<Elev> |
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| 93 | ::SetStandardElevator<LinkedElev> |
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| 94 | ::Create PreflowType; |
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| 95 | PreflowType preflow_test(g, cap, n, n); |
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| 96 | const PreflowType& const_preflow_test = preflow_test; |
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[389] | 97 | |
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[585] | 98 | preflow_test |
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| 99 | .capacityMap(cap) |
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| 100 | .flowMap(flow) |
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| 101 | .source(n) |
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| 102 | .target(n); |
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[389] | 103 | |
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| 104 | preflow_test.init(); |
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[392] | 105 | preflow_test.init(cap); |
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[389] | 106 | preflow_test.startFirstPhase(); |
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| 107 | preflow_test.startSecondPhase(); |
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| 108 | preflow_test.run(); |
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| 109 | preflow_test.runMinCut(); |
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| 110 | |
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[585] | 111 | v = const_preflow_test.flowValue(); |
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| 112 | v = const_preflow_test.flow(e); |
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| 113 | const FlowMap& fm = const_preflow_test.flowMap(); |
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| 114 | b = const_preflow_test.minCut(n); |
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| 115 | const_preflow_test.minCutMap(cut); |
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| 116 | |
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| 117 | ignore_unused_variable_warning(fm); |
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[389] | 118 | } |
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| 119 | |
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| 120 | int cutValue (const SmartDigraph& g, |
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| 121 | const SmartDigraph::NodeMap<bool>& cut, |
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| 122 | const SmartDigraph::ArcMap<int>& cap) { |
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| 123 | |
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| 124 | int c=0; |
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| 125 | for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) { |
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| 126 | if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e]; |
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| 127 | } |
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| 128 | return c; |
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| 129 | } |
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| 130 | |
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| 131 | bool checkFlow(const SmartDigraph& g, |
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| 132 | const SmartDigraph::ArcMap<int>& flow, |
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| 133 | const SmartDigraph::ArcMap<int>& cap, |
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| 134 | SmartDigraph::Node s, SmartDigraph::Node t) { |
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| 135 | |
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| 136 | for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) { |
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| 137 | if (flow[e] < 0 || flow[e] > cap[e]) return false; |
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| 138 | } |
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| 139 | |
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| 140 | for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) { |
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| 141 | if (n == s || n == t) continue; |
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| 142 | int sum = 0; |
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| 143 | for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) { |
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| 144 | sum += flow[e]; |
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| 145 | } |
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| 146 | for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) { |
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| 147 | sum -= flow[e]; |
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| 148 | } |
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| 149 | if (sum != 0) return false; |
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| 150 | } |
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| 151 | return true; |
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| 152 | } |
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| 153 | |
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| 154 | int main() { |
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| 155 | |
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| 156 | typedef SmartDigraph Digraph; |
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| 157 | |
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| 158 | typedef Digraph::Node Node; |
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| 159 | typedef Digraph::NodeIt NodeIt; |
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| 160 | typedef Digraph::ArcIt ArcIt; |
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| 161 | typedef Digraph::ArcMap<int> CapMap; |
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| 162 | typedef Digraph::ArcMap<int> FlowMap; |
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| 163 | typedef Digraph::NodeMap<bool> CutMap; |
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| 164 | |
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| 165 | typedef Preflow<Digraph, CapMap> PType; |
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| 166 | |
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| 167 | Digraph g; |
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| 168 | Node s, t; |
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| 169 | CapMap cap(g); |
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[423] | 170 | std::istringstream input(test_lgf); |
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| 171 | DigraphReader<Digraph>(g,input). |
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[389] | 172 | arcMap("capacity", cap). |
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| 173 | node("source",s). |
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| 174 | node("target",t). |
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| 175 | run(); |
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| 176 | |
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| 177 | PType preflow_test(g, cap, s, t); |
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| 178 | preflow_test.run(); |
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| 179 | |
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| 180 | check(checkFlow(g, preflow_test.flowMap(), cap, s, t), |
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| 181 | "The flow is not feasible."); |
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| 182 | |
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| 183 | CutMap min_cut(g); |
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| 184 | preflow_test.minCutMap(min_cut); |
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| 185 | int min_cut_value=cutValue(g,min_cut,cap); |
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| 186 | |
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| 187 | check(preflow_test.flowValue() == min_cut_value, |
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| 188 | "The max flow value is not equal to the three min cut values."); |
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| 189 | |
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| 190 | FlowMap flow(g); |
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| 191 | for(ArcIt e(g); e!=INVALID; ++e) flow[e] = preflow_test.flowMap()[e]; |
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| 192 | |
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| 193 | int flow_value=preflow_test.flowValue(); |
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| 194 | |
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| 195 | for(ArcIt e(g); e!=INVALID; ++e) cap[e]=2*cap[e]; |
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[392] | 196 | preflow_test.init(flow); |
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[389] | 197 | preflow_test.startFirstPhase(); |
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| 198 | |
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| 199 | CutMap min_cut1(g); |
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| 200 | preflow_test.minCutMap(min_cut1); |
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| 201 | min_cut_value=cutValue(g,min_cut1,cap); |
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| 202 | |
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| 203 | check(preflow_test.flowValue() == min_cut_value && |
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| 204 | min_cut_value == 2*flow_value, |
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| 205 | "The max flow value or the min cut value is wrong."); |
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| 206 | |
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| 207 | preflow_test.startSecondPhase(); |
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| 208 | |
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| 209 | check(checkFlow(g, preflow_test.flowMap(), cap, s, t), |
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| 210 | "The flow is not feasible."); |
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| 211 | |
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| 212 | CutMap min_cut2(g); |
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| 213 | preflow_test.minCutMap(min_cut2); |
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| 214 | min_cut_value=cutValue(g,min_cut2,cap); |
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| 215 | |
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| 216 | check(preflow_test.flowValue() == min_cut_value && |
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| 217 | min_cut_value == 2*flow_value, |
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| 218 | "The max flow value or the three min cut values were not doubled"); |
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| 219 | |
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| 220 | |
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| 221 | preflow_test.flowMap(flow); |
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| 222 | |
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| 223 | NodeIt tmp1(g,s); |
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| 224 | ++tmp1; |
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| 225 | if ( tmp1 != INVALID ) s=tmp1; |
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| 226 | |
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| 227 | NodeIt tmp2(g,t); |
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| 228 | ++tmp2; |
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| 229 | if ( tmp2 != INVALID ) t=tmp2; |
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| 230 | |
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| 231 | preflow_test.source(s); |
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| 232 | preflow_test.target(t); |
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| 233 | |
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| 234 | preflow_test.run(); |
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| 235 | |
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| 236 | CutMap min_cut3(g); |
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| 237 | preflow_test.minCutMap(min_cut3); |
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| 238 | min_cut_value=cutValue(g,min_cut3,cap); |
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| 239 | |
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| 240 | |
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| 241 | check(preflow_test.flowValue() == min_cut_value, |
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| 242 | "The max flow value or the three min cut values are incorrect."); |
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| 243 | |
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| 244 | return 0; |
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| 245 | } |
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