COIN-OR::LEMON - Graph Library

source: lemon-0.x/src/test/preflow_test.cc @ 887:ec6a528dafd2

Last change on this file since 887:ec6a528dafd2 was 887:ec6a528dafd2, checked in by jacint, 16 years ago

new test graph

  • Property exe set to *
File size: 4.3 KB
Line 
1#include <fstream>
2#include <string>
3
4#include "test_tools.h"
5#include <hugo/smart_graph.h>
6#include <hugo/dimacs.h>
7#include <hugo/preflow.h>
8#include <hugo/skeletons/graph.h>
9#include <hugo/skeletons/maps.h>
10
11using namespace hugo;
12
13void check_Preflow()
14{
15  typedef int VType;
16  typedef skeleton::StaticGraph Graph;
17
18  typedef Graph::Node Node;
19  typedef Graph::Edge Edge;
20  typedef skeleton::ReadMap<Edge,VType> CapMap;
21  typedef skeleton::ReadWriteMap<Edge,VType> FlowMap;
22  typedef skeleton::ReadWriteMap<Node,bool> CutMap;
23 
24  typedef Preflow<Graph, int, CapMap, FlowMap> PType;
25
26  Graph G;
27  Node n;
28  CapMap cap;
29  FlowMap flow;
30  CutMap cut;
31
32  PType preflow_test(G,n,n,cap,flow);
33
34  preflow_test.run();
35  preflow_test.flowValue();
36  preflow_test.setSource(n);
37  preflow_test.setFlow(flow);
38
39  preflow_test.phase1(PType::NO_FLOW);
40  preflow_test.minCut(cut);
41
42  preflow_test.phase2();
43  preflow_test.setTarget(n);
44  preflow_test.setCap(cap);
45  preflow_test.minMinCut(cut);
46  preflow_test.maxMinCut(cut);
47}
48
49int cut_value ( SmartGraph& G, SmartGraph::NodeMap<bool>& cut,
50                SmartGraph::EdgeMap<int>& cap) {
51 
52  int c=0;
53  for(SmartGraph::EdgeIt e(G); e!=INVALID; ++e) {
54    if (cut[G.tail(e)] && !cut[G.head(e)]) c+=cap[e];
55  }
56  return c;
57}
58
59int main() {
60
61  typedef SmartGraph Graph;
62 
63  typedef Graph::Node Node;
64  typedef Graph::NodeIt NodeIt;
65  typedef Graph::EdgeIt EdgeIt;
66  typedef Graph::EdgeMap<int> CapMap;
67  typedef Graph::EdgeMap<int> FlowMap;
68  typedef Graph::NodeMap<bool> CutMap;
69
70  typedef Preflow<Graph, int> PType;
71
72  std::string f_name;
73  if( getenv("srcdir") ) {
74    f_name = std::string(getenv("srcdir")) + "/preflow_graph.dim";
75  }
76  else {
77    f_name = "preflow_graph.dim";
78  }
79 
80  std::ifstream file(f_name.c_str());
81 
82  check(file, "Input file '" << f_name << "' not found.");
83 
84  Graph G;
85  Node s, t;
86  CapMap cap(G);
87  readDimacs(file, G, cap, s, t);
88
89  FlowMap flow(G,0);
90
91 
92
93  PType preflow_test(G, s, t, cap, flow);
94  preflow_test.run(PType::ZERO_FLOW);
95   
96  CutMap mincut(G,false);
97  preflow_test.minCut(mincut);
98  int min_cut_value=cut_value(G,mincut,cap);
99   
100  CutMap minmincut(G,false);
101  preflow_test.minMinCut(minmincut);
102  int min_min_cut_value=cut_value(G,minmincut,cap);
103   
104  CutMap maxmincut(G,false);
105  preflow_test.maxMinCut(maxmincut);
106  int max_min_cut_value=cut_value(G,maxmincut,cap);
107
108  check(preflow_test.flowValue() == min_cut_value &&
109        min_cut_value == min_min_cut_value &&
110        min_min_cut_value == max_min_cut_value,
111        "The max flow value is not equal to the three min cut values.");
112
113  int flow_value=preflow_test.flowValue();
114
115
116
117  for(EdgeIt e(G); e!=INVALID; ++e) cap[e]=2*cap[e];
118  preflow_test.setCap(cap); 
119
120  preflow_test.phase1(PType::PRE_FLOW);
121
122  CutMap mincut1(G,false);
123  preflow_test.minCut(mincut1);
124  min_cut_value=cut_value(G,mincut1,cap);
125   
126  check(preflow_test.flowValue() == min_cut_value &&
127        min_cut_value == 2*flow_value,
128        "The max flow value or the min cut value is wrong.");
129
130  preflow_test.phase2();
131
132  CutMap mincut2(G,false);
133  preflow_test.minCut(mincut2);
134  min_cut_value=cut_value(G,mincut2,cap);
135   
136  CutMap minmincut2(G,false);
137  preflow_test.minMinCut(minmincut2);
138  min_min_cut_value=cut_value(G,minmincut2,cap);
139 
140  preflow_test.maxMinCut(maxmincut);
141  max_min_cut_value=cut_value(G,maxmincut,cap);
142
143  check(preflow_test.flowValue() == min_cut_value &&
144        min_cut_value == min_min_cut_value &&
145        min_min_cut_value == max_min_cut_value &&
146        min_cut_value == 2*flow_value,
147        "The max flow value or the three min cut values were not doubled");
148
149
150
151  EdgeIt e(G);
152  for( int i=1; i==10; ++i ) {
153    flow.set(e,0);
154    ++e;
155  }
156
157  preflow_test.setFlow(flow);
158
159  NodeIt tmp1(G,s);
160  ++tmp1;
161  if ( tmp1 != INVALID ) s=tmp1;
162
163  NodeIt tmp2(G,t);
164  ++tmp2;
165  if ( tmp2 != INVALID ) t=tmp2;
166
167  preflow_test.setSource(s);
168  preflow_test.setTarget(t);
169 
170  preflow_test.run();
171
172  CutMap mincut3(G,false);
173  preflow_test.minCut(mincut3);
174  min_cut_value=cut_value(G,mincut3,cap);
175   
176  CutMap minmincut3(G,false);
177  preflow_test.minMinCut(minmincut3);
178  min_min_cut_value=cut_value(G,minmincut3,cap);
179   
180  preflow_test.maxMinCut(maxmincut);
181  max_min_cut_value=cut_value(G,maxmincut,cap);
182
183  check(preflow_test.flowValue() == min_cut_value &&
184        min_cut_value == min_min_cut_value &&
185        min_min_cut_value == max_min_cut_value,
186        "The max flow value or the three min cut values are incorrect.");
187}
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