Minimum cost flows of small values: algorithm from Andras Frank's lecture notes (approximately)
4 #include <list_graph.hh>
6 #include <preflow_push_max_flow.h>
7 #include <preflow_push_hl.h>
8 #include <time_measure.h>
12 // Use a DIMACS max flow file as stdin.
13 // read_dimacs_demo < dimacs_max_flow_file
14 int main(int, char **) {
15 typedef ListGraph::NodeIt NodeIt;
16 typedef ListGraph::EachEdgeIt EachEdgeIt;
20 ListGraph::EdgeMap<int> cap(G);
21 readDimacsMaxFlow(std::cin, G, s, t, cap);
24 std::cout << "preflow demo (preflow_push_max_flow by JACINT)..." << std::endl;
25 //ListGraph::EdgeMap<int> flow(G); //0 flow
27 double pre_time=currTime();
28 preflow_push_max_flow<ListGraph, int> max_flow_test(G, s, t, cap);
30 ListGraph::NodeMap<bool> cut(G);
31 max_flow_test.mincut(cut);
33 for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
34 if (cut.get(G.tail(e)) && !cut.get(G.head(e))) cut_value+=cap.get(e);
36 double post_time=currTime();
37 //std::cout << "maximum flow: "<< std::endl;
38 //for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
39 // std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
41 //std::cout<<std::endl;
42 std::cout << "elapsed time: " << post_time-pre_time << " sec"<< std::endl;
43 std::cout << "flow value: "<< max_flow_test.maxflow() << std::endl;
44 std::cout << "cut value: "<< cut_value << std::endl;
48 std::cout << "preflow demo (preflow_push_hl by JACINT)..." << std::endl;
49 //ListGraph::EdgeMap<int> flow(G); //0 flow
51 double pre_time=currTime();
52 preflow_push_hl<ListGraph, int> max_flow_test(G, s, t, cap);
54 ListGraph::NodeMap<bool> cut(G);
55 max_flow_test.mincut(cut);
57 for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
58 if (cut.get(G.tail(e)) && !cut.get(G.head(e))) cut_value+=cap.get(e);
60 double post_time=currTime();
61 //std::cout << "maximum flow: "<< std::endl;
62 //for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
63 // std::cout<<"("<<G.tail(e)<< "-"<<flow.get(e)<<"->"<<G.head(e)<<") ";
65 //std::cout<<std::endl;
66 std::cout << "elapsed time: " << post_time-pre_time << " sec"<< std::endl;
67 std::cout << "flow value: "<< max_flow_test.maxflow() << std::endl;
68 std::cout << "cut value: "<< cut_value << std::endl;