test/preflow_test.cc
author Alpar Juttner <alpar@cs.elte.hu>
Mon, 12 Apr 2010 16:52:48 +0200
branch1.1
changeset 973 290f3ca599d6
parent 463 88ed40ad0d4f
child 736 86c49553fea5
child 1027 30d5f950aa5f
permissions -rw-r--r--
Merge bugfix #366 to branch 1.1
alpar@404
     1
/* -*- mode: C++; indent-tabs-mode: nil; -*-
alpar@404
     2
 *
alpar@404
     3
 * This file is a part of LEMON, a generic C++ optimization library.
alpar@404
     4
 *
alpar@463
     5
 * Copyright (C) 2003-2009
alpar@404
     6
 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@404
     7
 * (Egervary Research Group on Combinatorial Optimization, EGRES).
alpar@404
     8
 *
alpar@404
     9
 * Permission to use, modify and distribute this software is granted
alpar@404
    10
 * provided that this copyright notice appears in all copies. For
alpar@404
    11
 * precise terms see the accompanying LICENSE file.
alpar@404
    12
 *
alpar@404
    13
 * This software is provided "AS IS" with no warranty of any kind,
alpar@404
    14
 * express or implied, and with no claim as to its suitability for any
alpar@404
    15
 * purpose.
alpar@404
    16
 *
alpar@404
    17
 */
alpar@404
    18
alpar@442
    19
#include <iostream>
alpar@404
    20
alpar@404
    21
#include "test_tools.h"
alpar@404
    22
#include <lemon/smart_graph.h>
alpar@404
    23
#include <lemon/preflow.h>
alpar@404
    24
#include <lemon/concepts/digraph.h>
alpar@404
    25
#include <lemon/concepts/maps.h>
alpar@404
    26
#include <lemon/lgf_reader.h>
kpeter@409
    27
#include <lemon/elevator.h>
alpar@404
    28
alpar@404
    29
using namespace lemon;
alpar@404
    30
alpar@442
    31
char test_lgf[] =
alpar@442
    32
  "@nodes\n"
alpar@442
    33
  "label\n"
alpar@442
    34
  "0\n"
alpar@442
    35
  "1\n"
alpar@442
    36
  "2\n"
alpar@442
    37
  "3\n"
alpar@442
    38
  "4\n"
alpar@442
    39
  "5\n"
alpar@442
    40
  "6\n"
alpar@442
    41
  "7\n"
alpar@442
    42
  "8\n"
alpar@442
    43
  "9\n"
alpar@442
    44
  "@arcs\n"
alpar@442
    45
  "    label capacity\n"
alpar@442
    46
  "0 1 0     20\n"
alpar@442
    47
  "0 2 1     0\n"
alpar@442
    48
  "1 1 2     3\n"
alpar@442
    49
  "1 2 3     8\n"
alpar@442
    50
  "1 3 4     8\n"
alpar@442
    51
  "2 5 5     5\n"
alpar@442
    52
  "3 2 6     5\n"
alpar@442
    53
  "3 5 7     5\n"
alpar@442
    54
  "3 6 8     5\n"
alpar@442
    55
  "4 3 9     3\n"
alpar@442
    56
  "5 7 10    3\n"
alpar@442
    57
  "5 6 11    10\n"
alpar@442
    58
  "5 8 12    10\n"
alpar@442
    59
  "6 8 13    8\n"
alpar@442
    60
  "8 9 14    20\n"
alpar@442
    61
  "8 1 15    5\n"
alpar@442
    62
  "9 5 16    5\n"
alpar@442
    63
  "@attributes\n"
alpar@442
    64
  "source 1\n"
alpar@442
    65
  "target 8\n";
alpar@442
    66
kpeter@409
    67
void checkPreflowCompile()
alpar@404
    68
{
alpar@404
    69
  typedef int VType;
alpar@404
    70
  typedef concepts::Digraph Digraph;
alpar@404
    71
alpar@404
    72
  typedef Digraph::Node Node;
alpar@404
    73
  typedef Digraph::Arc Arc;
alpar@404
    74
  typedef concepts::ReadMap<Arc,VType> CapMap;
alpar@404
    75
  typedef concepts::ReadWriteMap<Arc,VType> FlowMap;
alpar@404
    76
  typedef concepts::WriteMap<Node,bool> CutMap;
alpar@404
    77
kpeter@409
    78
  typedef Elevator<Digraph, Digraph::Node> Elev;
kpeter@409
    79
  typedef LinkedElevator<Digraph, Digraph::Node> LinkedElev;
kpeter@409
    80
alpar@404
    81
  Digraph g;
alpar@404
    82
  Node n;
alpar@404
    83
  Arc e;
alpar@404
    84
  CapMap cap;
alpar@404
    85
  FlowMap flow;
alpar@404
    86
  CutMap cut;
kpeter@632
    87
  VType v;
kpeter@632
    88
  bool b;
alpar@404
    89
kpeter@632
    90
  typedef Preflow<Digraph, CapMap>
kpeter@632
    91
            ::SetFlowMap<FlowMap>
kpeter@632
    92
            ::SetElevator<Elev>
kpeter@632
    93
            ::SetStandardElevator<LinkedElev>
kpeter@632
    94
            ::Create PreflowType;
kpeter@632
    95
  PreflowType preflow_test(g, cap, n, n);
kpeter@632
    96
  const PreflowType& const_preflow_test = preflow_test;
alpar@404
    97
kpeter@632
    98
  preflow_test
kpeter@632
    99
    .capacityMap(cap)
kpeter@632
   100
    .flowMap(flow)
kpeter@632
   101
    .source(n)
kpeter@632
   102
    .target(n);
alpar@404
   103
alpar@404
   104
  preflow_test.init();
kpeter@407
   105
  preflow_test.init(cap);
alpar@404
   106
  preflow_test.startFirstPhase();
alpar@404
   107
  preflow_test.startSecondPhase();
alpar@404
   108
  preflow_test.run();
alpar@404
   109
  preflow_test.runMinCut();
alpar@404
   110
kpeter@632
   111
  v = const_preflow_test.flowValue();
kpeter@632
   112
  v = const_preflow_test.flow(e);
kpeter@632
   113
  const FlowMap& fm = const_preflow_test.flowMap();
kpeter@632
   114
  b = const_preflow_test.minCut(n);
kpeter@632
   115
  const_preflow_test.minCutMap(cut);
kpeter@632
   116
  
kpeter@632
   117
  ignore_unused_variable_warning(fm);
alpar@404
   118
}
alpar@404
   119
alpar@404
   120
int cutValue (const SmartDigraph& g,
alpar@404
   121
              const SmartDigraph::NodeMap<bool>& cut,
alpar@404
   122
              const SmartDigraph::ArcMap<int>& cap) {
alpar@404
   123
alpar@404
   124
  int c=0;
alpar@404
   125
  for(SmartDigraph::ArcIt e(g); e!=INVALID; ++e) {
alpar@404
   126
    if (cut[g.source(e)] && !cut[g.target(e)]) c+=cap[e];
alpar@404
   127
  }
alpar@404
   128
  return c;
alpar@404
   129
}
alpar@404
   130
alpar@404
   131
bool checkFlow(const SmartDigraph& g,
alpar@404
   132
               const SmartDigraph::ArcMap<int>& flow,
alpar@404
   133
               const SmartDigraph::ArcMap<int>& cap,
alpar@404
   134
               SmartDigraph::Node s, SmartDigraph::Node t) {
alpar@404
   135
alpar@404
   136
  for (SmartDigraph::ArcIt e(g); e != INVALID; ++e) {
alpar@404
   137
    if (flow[e] < 0 || flow[e] > cap[e]) return false;
alpar@404
   138
  }
alpar@404
   139
alpar@404
   140
  for (SmartDigraph::NodeIt n(g); n != INVALID; ++n) {
alpar@404
   141
    if (n == s || n == t) continue;
alpar@404
   142
    int sum = 0;
alpar@404
   143
    for (SmartDigraph::OutArcIt e(g, n); e != INVALID; ++e) {
alpar@404
   144
      sum += flow[e];
alpar@404
   145
    }
alpar@404
   146
    for (SmartDigraph::InArcIt e(g, n); e != INVALID; ++e) {
alpar@404
   147
      sum -= flow[e];
alpar@404
   148
    }
alpar@404
   149
    if (sum != 0) return false;
alpar@404
   150
  }
alpar@404
   151
  return true;
alpar@404
   152
}
alpar@404
   153
alpar@404
   154
int main() {
alpar@404
   155
alpar@404
   156
  typedef SmartDigraph Digraph;
alpar@404
   157
alpar@404
   158
  typedef Digraph::Node Node;
alpar@404
   159
  typedef Digraph::NodeIt NodeIt;
alpar@404
   160
  typedef Digraph::ArcIt ArcIt;
alpar@404
   161
  typedef Digraph::ArcMap<int> CapMap;
alpar@404
   162
  typedef Digraph::ArcMap<int> FlowMap;
alpar@404
   163
  typedef Digraph::NodeMap<bool> CutMap;
alpar@404
   164
alpar@404
   165
  typedef Preflow<Digraph, CapMap> PType;
alpar@404
   166
alpar@404
   167
  Digraph g;
alpar@404
   168
  Node s, t;
alpar@404
   169
  CapMap cap(g);
alpar@442
   170
  std::istringstream input(test_lgf);
alpar@442
   171
  DigraphReader<Digraph>(g,input).
alpar@404
   172
    arcMap("capacity", cap).
alpar@404
   173
    node("source",s).
alpar@404
   174
    node("target",t).
alpar@404
   175
    run();
alpar@404
   176
alpar@404
   177
  PType preflow_test(g, cap, s, t);
alpar@404
   178
  preflow_test.run();
alpar@404
   179
alpar@404
   180
  check(checkFlow(g, preflow_test.flowMap(), cap, s, t),
alpar@404
   181
        "The flow is not feasible.");
alpar@404
   182
alpar@404
   183
  CutMap min_cut(g);
alpar@404
   184
  preflow_test.minCutMap(min_cut);
alpar@404
   185
  int min_cut_value=cutValue(g,min_cut,cap);
alpar@404
   186
alpar@404
   187
  check(preflow_test.flowValue() == min_cut_value,
alpar@404
   188
        "The max flow value is not equal to the three min cut values.");
alpar@404
   189
alpar@404
   190
  FlowMap flow(g);
alpar@404
   191
  for(ArcIt e(g); e!=INVALID; ++e) flow[e] = preflow_test.flowMap()[e];
alpar@404
   192
alpar@404
   193
  int flow_value=preflow_test.flowValue();
alpar@404
   194
alpar@404
   195
  for(ArcIt e(g); e!=INVALID; ++e) cap[e]=2*cap[e];
kpeter@407
   196
  preflow_test.init(flow);
alpar@404
   197
  preflow_test.startFirstPhase();
alpar@404
   198
alpar@404
   199
  CutMap min_cut1(g);
alpar@404
   200
  preflow_test.minCutMap(min_cut1);
alpar@404
   201
  min_cut_value=cutValue(g,min_cut1,cap);
alpar@404
   202
alpar@404
   203
  check(preflow_test.flowValue() == min_cut_value &&
alpar@404
   204
        min_cut_value == 2*flow_value,
alpar@404
   205
        "The max flow value or the min cut value is wrong.");
alpar@404
   206
alpar@404
   207
  preflow_test.startSecondPhase();
alpar@404
   208
alpar@404
   209
  check(checkFlow(g, preflow_test.flowMap(), cap, s, t),
alpar@404
   210
        "The flow is not feasible.");
alpar@404
   211
alpar@404
   212
  CutMap min_cut2(g);
alpar@404
   213
  preflow_test.minCutMap(min_cut2);
alpar@404
   214
  min_cut_value=cutValue(g,min_cut2,cap);
alpar@404
   215
alpar@404
   216
  check(preflow_test.flowValue() == min_cut_value &&
alpar@404
   217
        min_cut_value == 2*flow_value,
alpar@404
   218
        "The max flow value or the three min cut values were not doubled");
alpar@404
   219
alpar@404
   220
alpar@404
   221
  preflow_test.flowMap(flow);
alpar@404
   222
alpar@404
   223
  NodeIt tmp1(g,s);
alpar@404
   224
  ++tmp1;
alpar@404
   225
  if ( tmp1 != INVALID ) s=tmp1;
alpar@404
   226
alpar@404
   227
  NodeIt tmp2(g,t);
alpar@404
   228
  ++tmp2;
alpar@404
   229
  if ( tmp2 != INVALID ) t=tmp2;
alpar@404
   230
alpar@404
   231
  preflow_test.source(s);
alpar@404
   232
  preflow_test.target(t);
alpar@404
   233
alpar@404
   234
  preflow_test.run();
alpar@404
   235
alpar@404
   236
  CutMap min_cut3(g);
alpar@404
   237
  preflow_test.minCutMap(min_cut3);
alpar@404
   238
  min_cut_value=cutValue(g,min_cut3,cap);
alpar@404
   239
alpar@404
   240
alpar@404
   241
  check(preflow_test.flowValue() == min_cut_value,
alpar@404
   242
        "The max flow value or the three min cut values are incorrect.");
alpar@404
   243
alpar@404
   244
  return 0;
alpar@404
   245
}