[906] | 1 | /* -*- C++ -*- |
---|
| 2 | * |
---|
[1956] | 3 | * This file is a part of LEMON, a generic C++ optimization library |
---|
| 4 | * |
---|
[2391] | 5 | * Copyright (C) 2003-2007 |
---|
[1956] | 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
---|
[1359] | 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
---|
[906] | 8 | * |
---|
| 9 | * Permission to use, modify and distribute this software is granted |
---|
| 10 | * provided that this copyright notice appears in all copies. For |
---|
| 11 | * precise terms see the accompanying LICENSE file. |
---|
| 12 | * |
---|
| 13 | * This software is provided "AS IS" with no warranty of any kind, |
---|
| 14 | * express or implied, and with no claim as to its suitability for any |
---|
| 15 | * purpose. |
---|
| 16 | * |
---|
| 17 | */ |
---|
| 18 | |
---|
[833] | 19 | #include <fstream> |
---|
[858] | 20 | #include <string> |
---|
| 21 | |
---|
[833] | 22 | #include "test_tools.h" |
---|
[921] | 23 | #include <lemon/smart_graph.h> |
---|
| 24 | #include <lemon/dimacs.h> |
---|
| 25 | #include <lemon/preflow.h> |
---|
[2260] | 26 | #include <lemon/concepts/graph.h> |
---|
| 27 | #include <lemon/concepts/maps.h> |
---|
[855] | 28 | |
---|
[921] | 29 | using namespace lemon; |
---|
[833] | 30 | |
---|
[2514] | 31 | void checkPreflow() |
---|
[833] | 32 | { |
---|
| 33 | typedef int VType; |
---|
[2260] | 34 | typedef concepts::Graph Graph; |
---|
[833] | 35 | |
---|
| 36 | typedef Graph::Node Node; |
---|
| 37 | typedef Graph::Edge Edge; |
---|
[2260] | 38 | typedef concepts::ReadMap<Edge,VType> CapMap; |
---|
| 39 | typedef concepts::ReadWriteMap<Edge,VType> FlowMap; |
---|
[2514] | 40 | typedef concepts::WriteMap<Node,bool> CutMap; |
---|
[833] | 41 | |
---|
[940] | 42 | Graph g; |
---|
[833] | 43 | Node n; |
---|
[2514] | 44 | Edge e; |
---|
[833] | 45 | CapMap cap; |
---|
| 46 | FlowMap flow; |
---|
| 47 | CutMap cut; |
---|
| 48 | |
---|
[2514] | 49 | Preflow<Graph, CapMap>::DefFlowMap<FlowMap>::Create preflow_test(g,cap,n,n); |
---|
[833] | 50 | |
---|
[2514] | 51 | preflow_test.capacityMap(cap); |
---|
| 52 | flow = preflow_test.flowMap(); |
---|
| 53 | preflow_test.flowMap(flow); |
---|
| 54 | preflow_test.source(n); |
---|
| 55 | preflow_test.target(n); |
---|
| 56 | |
---|
| 57 | preflow_test.init(); |
---|
| 58 | preflow_test.flowInit(cap); |
---|
| 59 | preflow_test.startFirstPhase(); |
---|
| 60 | preflow_test.startSecondPhase(); |
---|
[833] | 61 | preflow_test.run(); |
---|
[2514] | 62 | preflow_test.runMinCut(); |
---|
| 63 | |
---|
[833] | 64 | preflow_test.flowValue(); |
---|
[2514] | 65 | preflow_test.minCut(n); |
---|
| 66 | preflow_test.minCutMap(cut); |
---|
| 67 | preflow_test.flow(e); |
---|
[833] | 68 | |
---|
| 69 | } |
---|
| 70 | |
---|
[2514] | 71 | int cutValue (const SmartGraph& g, |
---|
| 72 | const SmartGraph::NodeMap<bool>& cut, |
---|
| 73 | const SmartGraph::EdgeMap<int>& cap) { |
---|
[833] | 74 | |
---|
| 75 | int c=0; |
---|
[940] | 76 | for(SmartGraph::EdgeIt e(g); e!=INVALID; ++e) { |
---|
[986] | 77 | if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e]; |
---|
[833] | 78 | } |
---|
| 79 | return c; |
---|
| 80 | } |
---|
| 81 | |
---|
[2514] | 82 | bool checkFlow(const SmartGraph& g, |
---|
| 83 | const SmartGraph::EdgeMap<int>& flow, |
---|
| 84 | const SmartGraph::EdgeMap<int>& cap, |
---|
| 85 | SmartGraph::Node s, SmartGraph::Node t) { |
---|
| 86 | |
---|
| 87 | for (SmartGraph::EdgeIt e(g); e != INVALID; ++e) { |
---|
| 88 | if (flow[e] < 0 || flow[e] > cap[e]) return false; |
---|
| 89 | } |
---|
| 90 | |
---|
| 91 | for (SmartGraph::NodeIt n(g); n != INVALID; ++n) { |
---|
| 92 | if (n == s || n == t) continue; |
---|
| 93 | int sum = 0; |
---|
| 94 | for (SmartGraph::OutEdgeIt e(g, n); e != INVALID; ++e) { |
---|
| 95 | sum += flow[e]; |
---|
| 96 | } |
---|
| 97 | for (SmartGraph::InEdgeIt e(g, n); e != INVALID; ++e) { |
---|
| 98 | sum -= flow[e]; |
---|
| 99 | } |
---|
| 100 | if (sum != 0) return false; |
---|
| 101 | } |
---|
| 102 | return true; |
---|
| 103 | } |
---|
| 104 | |
---|
[833] | 105 | int main() { |
---|
| 106 | |
---|
| 107 | typedef SmartGraph Graph; |
---|
| 108 | |
---|
[842] | 109 | typedef Graph::Node Node; |
---|
[833] | 110 | typedef Graph::NodeIt NodeIt; |
---|
| 111 | typedef Graph::EdgeIt EdgeIt; |
---|
| 112 | typedef Graph::EdgeMap<int> CapMap; |
---|
| 113 | typedef Graph::EdgeMap<int> FlowMap; |
---|
| 114 | typedef Graph::NodeMap<bool> CutMap; |
---|
| 115 | |
---|
[2514] | 116 | typedef Preflow<Graph, CapMap> PType; |
---|
[833] | 117 | |
---|
[859] | 118 | std::string f_name; |
---|
[1215] | 119 | if( getenv("srcdir") ) |
---|
| 120 | f_name = std::string(getenv("srcdir")); |
---|
| 121 | else f_name = "."; |
---|
[2108] | 122 | f_name += "/test/preflow_graph.dim"; |
---|
[855] | 123 | |
---|
[858] | 124 | std::ifstream file(f_name.c_str()); |
---|
[855] | 125 | |
---|
[858] | 126 | check(file, "Input file '" << f_name << "' not found."); |
---|
[833] | 127 | |
---|
[940] | 128 | Graph g; |
---|
[842] | 129 | Node s, t; |
---|
[940] | 130 | CapMap cap(g); |
---|
| 131 | readDimacs(file, g, cap, s, t); |
---|
[833] | 132 | |
---|
[2514] | 133 | PType preflow_test(g, cap, s, t); |
---|
| 134 | preflow_test.run(); |
---|
| 135 | |
---|
| 136 | check(checkFlow(g, preflow_test.flowMap(), cap, s, t), |
---|
| 137 | "The flow is not feasible."); |
---|
[887] | 138 | |
---|
[2514] | 139 | CutMap min_cut(g); |
---|
| 140 | preflow_test.minCutMap(min_cut); |
---|
| 141 | int min_cut_value=cutValue(g,min_cut,cap); |
---|
| 142 | |
---|
| 143 | check(preflow_test.flowValue() == min_cut_value, |
---|
| 144 | "The max flow value is not equal to the three min cut values."); |
---|
[887] | 145 | |
---|
[2514] | 146 | FlowMap flow(g); |
---|
| 147 | flow = preflow_test.flowMap(); |
---|
[833] | 148 | |
---|
| 149 | int flow_value=preflow_test.flowValue(); |
---|
| 150 | |
---|
[2514] | 151 | for(EdgeIt e(g); e!=INVALID; ++e) cap[e]=2*cap[e]; |
---|
| 152 | preflow_test.flowInit(flow); |
---|
| 153 | preflow_test.startFirstPhase(); |
---|
[833] | 154 | |
---|
[2514] | 155 | CutMap min_cut1(g); |
---|
| 156 | preflow_test.minCutMap(min_cut1); |
---|
| 157 | min_cut_value=cutValue(g,min_cut1,cap); |
---|
[833] | 158 | |
---|
| 159 | check(preflow_test.flowValue() == min_cut_value && |
---|
| 160 | min_cut_value == 2*flow_value, |
---|
| 161 | "The max flow value or the min cut value is wrong."); |
---|
| 162 | |
---|
[2514] | 163 | preflow_test.startSecondPhase(); |
---|
[833] | 164 | |
---|
[2514] | 165 | check(checkFlow(g, preflow_test.flowMap(), cap, s, t), |
---|
| 166 | "The flow is not feasible."); |
---|
| 167 | |
---|
| 168 | CutMap min_cut2(g); |
---|
| 169 | preflow_test.minCutMap(min_cut2); |
---|
| 170 | min_cut_value=cutValue(g,min_cut2,cap); |
---|
[833] | 171 | |
---|
| 172 | check(preflow_test.flowValue() == min_cut_value && |
---|
| 173 | min_cut_value == 2*flow_value, |
---|
| 174 | "The max flow value or the three min cut values were not doubled"); |
---|
| 175 | |
---|
[887] | 176 | |
---|
[1222] | 177 | preflow_test.flowMap(flow); |
---|
[887] | 178 | |
---|
[940] | 179 | NodeIt tmp1(g,s); |
---|
[887] | 180 | ++tmp1; |
---|
| 181 | if ( tmp1 != INVALID ) s=tmp1; |
---|
| 182 | |
---|
[940] | 183 | NodeIt tmp2(g,t); |
---|
[887] | 184 | ++tmp2; |
---|
| 185 | if ( tmp2 != INVALID ) t=tmp2; |
---|
| 186 | |
---|
[1222] | 187 | preflow_test.source(s); |
---|
| 188 | preflow_test.target(t); |
---|
[887] | 189 | |
---|
[833] | 190 | preflow_test.run(); |
---|
| 191 | |
---|
[2514] | 192 | CutMap min_cut3(g); |
---|
| 193 | preflow_test.minCutMap(min_cut3); |
---|
| 194 | min_cut_value=cutValue(g,min_cut3,cap); |
---|
[833] | 195 | |
---|
| 196 | |
---|
[2514] | 197 | check(preflow_test.flowValue() == min_cut_value, |
---|
[833] | 198 | "The max flow value or the three min cut values are incorrect."); |
---|
[2514] | 199 | |
---|
| 200 | return 0; |
---|
[833] | 201 | } |
---|