2 The only difference between preflow.h and preflow_res.h is that the latter
3 uses the ResGraphWrapper, while the first does not. (Bfs is implemented by
4 hand in both.) This test program runs Preflow and PreflowRes on the same
5 graph, tests the result of these implementations and writes the running time
9 #include <smart_graph.h>
11 #include <preflow_excess.h>
12 #include <time_measure.h>
14 using namespace lemon;
16 int main(int, char **) {
18 typedef SmartGraph Graph;
20 typedef Graph::Node Node;
21 typedef Graph::EdgeIt EdgeIt;
25 Graph::EdgeMap<int> cap(G);
26 readDimacsMaxFlow(std::cin, G, s, t, cap);
33 "\n Running preflow.h on a graph with " <<
34 G.nodeNum() << " nodes and " << G.edgeNum() << " edges..."
35 << std::endl<<std::endl;
43 Graph::EdgeMap<int> flow(G,0);
44 Preflow<Graph, int> max_flow_test(G, s, t, cap, flow, 0 , 0);
47 std::cout << "Elapsed time from a preflow: " << std::endl
50 Graph::NodeMap<bool> mincut(G);
51 max_flow_test.minMinCut(mincut);
52 int min_min_cut_value=0;
54 for(G.first(e); G.valid(e); G.next(e)) {
55 if (mincut[G.source(e)] && !mincut[G.target(e)]) min_min_cut_value+=cap[e];
58 Graph::NodeMap<bool> cut(G);
59 max_flow_test.minCut(cut);
61 for(G.first(e); G.valid(e); G.next(e)) {
62 if (cut[G.source(e)] && !cut[G.target(e)])
63 min_cut_value+=cap[e];
66 Graph::NodeMap<bool> maxcut(G);
67 max_flow_test.maxMinCut(maxcut);
68 int max_min_cut_value=0;
69 for(G.first(e); G.valid(e); G.next(e)) {
70 if (maxcut[G.source(e)] && !maxcut[G.target(e)])
71 max_min_cut_value+=cap[e];
74 std::cout << "\n Checking the result: " <<std::endl;
75 std::cout << "Flow value: "<< max_flow_test.flowValue() << std::endl;
76 std::cout << "Min cut value: "<< min_cut_value << std::endl;
77 std::cout << "Min min cut value: "<< min_min_cut_value << std::endl;
78 std::cout << "Max min cut value: "<< max_min_cut_value <<
81 if ( max_flow_test.flowValue() == min_cut_value &&
82 min_cut_value == min_min_cut_value &&
83 min_min_cut_value == max_min_cut_value )
84 std::cout << "They are equal! " <<std::endl<< std::endl<<"\n";
91 Graph::EdgeMap<int> flow2(G,0);
92 Preflow<Graph, int> max_flow_test2(G, s, t, cap, flow2, 0 , 1);
95 std::cout << "Elapsed time from a flow: " << std::endl
98 Graph::NodeMap<bool> mincut2(G);
99 max_flow_test2.minMinCut(mincut2);
100 int min_min_cut_value2=0;
101 for(G.first(e); G.valid(e); G.next(e)) {
102 if (mincut2[G.source(e)] && !mincut2[G.target(e)]) min_min_cut_value2+=cap[e];
105 Graph::NodeMap<bool> cut2(G);
106 max_flow_test2.minCut(cut2);
107 int min_cut_value2=0;
108 for(G.first(e); G.valid(e); G.next(e)) {
109 if (cut2[G.source(e)] && !cut2[G.target(e)])
110 min_cut_value2+=cap[e];
113 Graph::NodeMap<bool> maxcut2(G);
114 max_flow_test2.maxMinCut(maxcut2);
115 int max_min_cut_value2=0;
116 for(G.first(e); G.valid(e); G.next(e)) {
117 if (maxcut2[G.source(e)] && !maxcut2[G.target(e)])
118 max_min_cut_value2+=cap[e];
121 std::cout << "\n Checking the result: " <<std::endl;
122 std::cout << "Flow value: "<< max_flow_test2.flowValue() << std::endl;
123 std::cout << "Min cut value: "<< min_cut_value2 << std::endl;
124 std::cout << "Min min cut value: "<< min_min_cut_value2 << std::endl;
125 std::cout << "Max min cut value: "<< max_min_cut_value2 <<
127 if ( max_flow_test.flowValue() == min_cut_value &&
128 min_cut_value == min_min_cut_value &&
129 min_min_cut_value == max_min_cut_value )
130 std::cout << "They are equal! " <<std::endl;
136 Graph::EdgeMap<int> flow3(G,0);
137 Preflow<Graph, int> max_flow_test3(G, s, t, cap, flow3, 1 , 1);
139 max_flow_test3.run();
140 std::cout << "Elapsed time from a const zero flow: " << std::endl
143 Graph::NodeMap<bool> mincut3(G);
144 max_flow_test3.minMinCut(mincut3);
145 int min_min_cut_value3=0;
146 for(G.first(e); G.valid(e); G.next(e)) {
147 if (mincut3[G.source(e)] && !mincut3[G.target(e)]) min_min_cut_value3+=cap[e];
150 Graph::NodeMap<bool> cut3(G);
151 max_flow_test3.minCut(cut3);
152 int min_cut_value3=0;
153 for(G.first(e); G.valid(e); G.next(e)) {
154 if (cut3[G.source(e)] && !cut3[G.target(e)])
155 min_cut_value3+=cap[e];
158 Graph::NodeMap<bool> maxcut3(G);
159 max_flow_test3.maxMinCut(maxcut3);
160 int max_min_cut_value3=0;
161 for(G.first(e); G.valid(e); G.next(e)) {
162 if (maxcut3[G.source(e)] && !maxcut3[G.target(e)])
163 max_min_cut_value3+=cap[e];
166 std::cout << "\n Checking the result: " <<std::endl;
167 std::cout << "Flow value: "<< max_flow_test3.flowValue() << std::endl;
168 std::cout << "Min cut value: "<< min_cut_value3 << std::endl;
169 std::cout << "Min min cut value: "<< min_min_cut_value3 << std::endl;
170 std::cout << "Max min cut value: "<< max_min_cut_value3 <<
173 if ( max_flow_test3.flowValue() == min_cut_value3 &&
174 min_cut_value3 == min_min_cut_value3 &&
175 min_min_cut_value3 == max_min_cut_value3 )
176 std::cout << "They are equal! " <<std::endl<< std::endl<<"\n";