Finished MinLengthPaths: a specialization of MinCostFlows.
3 #include <list_graph.h>
6 #include <time_measure.h>
10 int main(int, char **) {
12 typedef ListGraph Graph;
14 typedef Graph::Node Node;
15 typedef Graph::EdgeIt EdgeIt;
19 Graph::EdgeMap<int> cap(G);
20 readDimacs(std::cin, G, cap, s, t);
24 "\n Running max_flow.h on a graph with " <<
25 G.nodeNum() << " nodes and " << G.edgeNum() << " edges..."
26 << std::endl<<std::endl;
28 Graph::EdgeMap<int> flow(G,0);
29 MaxFlow<Graph, int> max_flow_test(G, s, t, cap, flow);
32 std::cout << "Elapsed time of run(): " << std::endl
35 Graph::NodeMap<bool> mincut(G);
36 max_flow_test.minMinCut(mincut);
37 int min_min_cut_value=0;
39 for(G.first(e); G.valid(e); G.next(e)) {
40 if (mincut[G.tail(e)] && !mincut[G.head(e)]) min_min_cut_value+=cap[e];
43 Graph::NodeMap<bool> cut(G);
44 max_flow_test.minCut(cut);
46 for(G.first(e); G.valid(e); G.next(e)) {
47 if (cut[G.tail(e)] && !cut[G.head(e)])
48 min_cut_value+=cap[e];
51 Graph::NodeMap<bool> maxcut(G);
52 max_flow_test.maxMinCut(maxcut);
53 int max_min_cut_value=0;
54 for(G.first(e); G.valid(e); G.next(e)) {
55 if (maxcut[G.tail(e)] && !maxcut[G.head(e)])
56 max_min_cut_value+=cap[e];
59 std::cout << "\n Checking the result: " <<std::endl;
60 std::cout << "Flow value: "<< max_flow_test.flowValue() << std::endl;
61 std::cout << "Min cut value: "<< min_cut_value << std::endl;
62 std::cout << "Min min cut value: "<< min_min_cut_value << std::endl;
63 std::cout << "Max min cut value: "<< max_min_cut_value <<
66 if ( max_flow_test.flowValue() == min_cut_value &&
67 min_cut_value == min_min_cut_value &&
68 min_min_cut_value == max_min_cut_value )
69 std::cout << "They are equal! " <<std::endl<< std::endl<<"\n";
73 Graph::EdgeMap<int> flow2(G,0);
74 std::cout << "Calling resetFlow() " << std::endl
76 max_flow_test.resetFlow(flow2);
78 max_flow_test.preflow(max_flow_test.PRE_FLOW);
79 std::cout << "Elapsed time of preflow(PRE_FLOW) starting from the zero flow: " << std::endl
82 Graph::NodeMap<bool> mincut2(G);
83 max_flow_test.minMinCut(mincut2);
84 int min_min_cut_value2=0;
85 for(G.first(e); G.valid(e); G.next(e)) {
86 if (mincut2[G.tail(e)] && !mincut2[G.head(e)]) min_min_cut_value2+=cap[e];
89 Graph::NodeMap<bool> cut2(G);
90 max_flow_test.minCut(cut2);
92 for(G.first(e); G.valid(e); G.next(e)) {
93 if (cut2[G.tail(e)] && !cut2[G.head(e)])
94 min_cut_value2+=cap[e];
97 Graph::NodeMap<bool> maxcut2(G);
98 max_flow_test.maxMinCut(maxcut2);
99 int max_min_cut_value2=0;
100 for(G.first(e); G.valid(e); G.next(e)) {
101 if (maxcut2[G.tail(e)] && !maxcut2[G.head(e)])
102 max_min_cut_value2+=cap[e];
105 std::cout << "\n Checking the result: " <<std::endl;
106 std::cout << "Flow value: "<< max_flow_test.flowValue() << std::endl;
107 std::cout << "Min cut value: "<< min_cut_value2 << std::endl;
108 std::cout << "Min min cut value: "<< min_min_cut_value2 << std::endl;
109 std::cout << "Max min cut value: "<< max_min_cut_value2 <<
111 if ( max_flow_test.flowValue() == min_cut_value &&
112 min_cut_value == min_min_cut_value &&
113 min_min_cut_value == max_min_cut_value )
114 std::cout << "They are equal! " <<std::endl;
117 MaxFlow<Graph, int> max_flow_test3(G, s, t, cap, flow2);
118 max_flow_test3.run(max_flow_test3.GEN_FLOW);
119 std::cout << "Calling run(GEN_FLOW) from the max flow found before. " <<std::endl;
121 Graph::NodeMap<bool> mincut3(G);
122 max_flow_test3.minMinCut(mincut3);
123 int min_min_cut_value3=0;
124 for(G.first(e); G.valid(e); G.next(e)) {
125 if (mincut3[G.tail(e)] && !mincut3[G.head(e)]) min_min_cut_value3+=cap[e];
128 Graph::NodeMap<bool> cut3(G);
129 max_flow_test3.minCut(cut3);
130 int min_cut_value3=0;
131 for(G.first(e); G.valid(e); G.next(e)) {
132 if (cut3[G.tail(e)] && !cut3[G.head(e)])
133 min_cut_value3+=cap[e];
136 Graph::NodeMap<bool> maxcut3(G);
137 max_flow_test3.maxMinCut(maxcut3);
138 int max_min_cut_value3=0;
139 for(G.first(e); G.valid(e); G.next(e)) {
140 if (maxcut3[G.tail(e)] && !maxcut3[G.head(e)])
141 max_min_cut_value3+=cap[e];
144 std::cout << "\n Checking the result: " <<std::endl;
145 std::cout << "Flow value: "<< max_flow_test3.flowValue() << std::endl;
146 std::cout << "Min cut value: "<< min_cut_value3 << std::endl;
147 std::cout << "Min min cut value: "<< min_min_cut_value3 << std::endl;
148 std::cout << "Max min cut value: "<< max_min_cut_value3 <<
151 if ( max_flow_test3.flowValue() == min_cut_value3 &&
152 min_cut_value3 == min_min_cut_value3 &&
153 min_min_cut_value3 == max_min_cut_value3 )
154 std::cout << "They are equal! " <<std::endl<< std::endl<<"\n";