src/work/jacint/preflow.cc
changeset 340 a2ce3c4780b7
parent 211 9222a9b8b323
child 372 e6a156fc186d
equal deleted inserted replaced
2:2c48c47bef57 3:39e6491d433f
     1 #include <iostream>
     1 #include <iostream>
     2 #include <fstream>
     2 #include <fstream>
     3 
     3 
       
     4 #include <smart_graph.h>
     4 #include <list_graph.h>
     5 #include <list_graph.h>
     5 #include <dimacs.h>
     6 #include <dimacs.h>
     6 #include <preflow.h>
     7 #include <preflow.h>
     7 #include <time_measure.h>
     8 #include <time_measure.h>
     8 
     9 
     9 using namespace hugo;
    10 using namespace hugo;
    10 
    11 
    11 // Use a DIMACS max flow file as stdin.
    12 // Use a DIMACS max flow file as stdin.
    12 // read_dimacs_demo < dimacs_max_flow_file
    13 // read_dimacs_demo < dimacs_max_flow_file
    13 int main(int, char **) {
    14 int main(int, char **) {
    14   typedef ListGraph::Node Node;
    15   typedef SmartGraph::Node Node;
    15   typedef ListGraph::EdgeIt EdgeIt;
    16   typedef SmartGraph::EdgeIt EdgeIt;
    16 
    17 
    17   ListGraph G;
    18   SmartGraph G;
    18   Node s, t;
    19   Node s, t;
    19   ListGraph::EdgeMap<int> cap(G);
    20   SmartGraph::EdgeMap<int> cap(G);
    20   readDimacsMaxFlow(std::cin, G, s, t, cap);
    21   readDimacsMaxFlow(std::cin, G, s, t, cap);
    21 
    22 
    22   std::cout << "preflow demo ..." << std::endl;
    23   std::cout << "preflow demo ..." << std::endl;
    23   
    24   
    24   double mintime=1000000;
    25   double mintime=1000000;
    25 
    26 
    26   for ( int i=1; i!=11; ++i ) {
    27   for ( int i=1; i!=11; ++i ) {
    27     ListGraph::EdgeMap<int> flow(G);
    28     SmartGraph::EdgeMap<int> flow(G);
    28     double pre_time=currTime();
    29     double pre_time=currTime();
    29     Preflow<ListGraph, int> max_flow_test(G, s, t, cap, flow);
    30     Preflow<SmartGraph, int> max_flow_test(G, s, t, cap, flow);
    30     max_flow_test.run();
    31     max_flow_test.run();
    31     double post_time=currTime();
    32     double post_time=currTime();
    32     if ( mintime > post_time-pre_time ) mintime = post_time-pre_time;
    33     if ( mintime > post_time-pre_time ) mintime = post_time-pre_time;
    33   }
    34   }
    34 
    35 
    35   ListGraph::EdgeMap<int> flow(G);
    36   SmartGraph::EdgeMap<int> flow(G);
    36   Preflow<ListGraph, int> max_flow_test(G, s, t, cap, flow);
    37   Preflow<SmartGraph, int> max_flow_test(G, s, t, cap, flow);
    37   max_flow_test.run();
    38   max_flow_test.run();
    38   
    39   
    39   ListGraph::NodeMap<bool> cut(G);
    40   SmartGraph::NodeMap<bool> cut(G);
    40   max_flow_test.minCut(cut); 
    41   max_flow_test.minCut(cut); 
    41   int min_cut_value=0;
    42   int min_cut_value=0;
    42   EdgeIt e;
    43   EdgeIt e;
    43   for(G.first(e); G.valid(e); G.next(e)) {
    44   for(G.first(e); G.valid(e); G.next(e)) {
    44     if (cut.get(G.tail(e)) && !cut.get(G.head(e))) min_cut_value+=cap.get(e);
    45     if (cut[G.tail(e)] && !cut[G.head(e)]) min_cut_value+=cap[e];
    45   }
    46   }
    46 
    47 
    47   ListGraph::NodeMap<bool> cut1(G);
    48   SmartGraph::NodeMap<bool> cut1(G);
    48   max_flow_test.minMinCut(cut1); 
    49   max_flow_test.minMinCut(cut1); 
    49   int min_min_cut_value=0;
    50   int min_min_cut_value=0;
    50   for(G.first(e); G.valid(e); G.next(e)) {
    51   for(G.first(e); G.valid(e); G.next(e)) {
    51     if (cut.get(G.tail(e)) && !cut.get(G.head(e))) 
    52     if (cut[G.tail(e)] && !cut[G.head(e)]) 
    52       min_min_cut_value+=cap.get(e);
    53       min_min_cut_value+=cap[e];
    53   }
    54   }
    54 
    55 
    55   ListGraph::NodeMap<bool> cut2(G);
    56   SmartGraph::NodeMap<bool> cut2(G);
    56   max_flow_test.maxMinCut(cut2); 
    57   max_flow_test.maxMinCut(cut2); 
    57   int max_min_cut_value=0;
    58   int max_min_cut_value=0;
    58   for(G.first(e); G.valid(e); G.next(e)) {
    59   for(G.first(e); G.valid(e); G.next(e)) {
    59     if (cut2.get(G.tail(e)) && !cut2.get(G.head(e))) 
    60     if (cut2[G.tail(e)] && !cut2[G.head(e)]) 
    60       max_min_cut_value+=cap.get(e);
    61       max_min_cut_value+=cap[e];
    61       }
    62       }
    62   
    63   
    63   std::cout << "min time of 10 runs: " << mintime << " sec"<< std::endl; 
    64   std::cout << "min time of 10 runs: " << mintime << " sec"<< std::endl; 
    64   std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
    65   std::cout << "flow value: "<< max_flow_test.flowValue() << std::endl;
    65   std::cout << "min cut value: "<< min_cut_value << std::endl;
    66   std::cout << "min cut value: "<< min_cut_value << std::endl;