src/work/jacint/preflow.cc
author marci
Mon, 01 Mar 2004 12:06:56 +0000
changeset 138 c6297c121409
parent 109 fc5982b39e10
child 211 9222a9b8b323
permissions -rw-r--r--
.
     1 #include <iostream>
     2 #include <fstream>
     3 
     4 #include <list_graph.hh>
     5 #include <dimacs.hh>
     6 #include <preflow.h>
     7 #include <time_measure.h>
     8 
     9 using namespace hugo;
    10 
    11 // Use a DIMACS max flow file as stdin.
    12 // read_dimacs_demo < dimacs_max_flow_file
    13 int main(int, char **) {
    14   typedef ListGraph::NodeIt NodeIt;
    15   typedef ListGraph::EachEdgeIt EachEdgeIt;
    16 
    17   ListGraph G;
    18   NodeIt s, t;
    19   ListGraph::EdgeMap<int> cap(G);
    20   readDimacsMaxFlow(std::cin, G, s, t, cap);
    21 
    22   std::cout << "preflow demo ..." << std::endl;
    23   
    24   double mintime=1000000;
    25 
    26   for ( int i=1; i!=11; ++i ) {
    27     double pre_time=currTime();
    28     preflow<ListGraph, int> max_flow_test(G, s, t, cap);
    29     double post_time=currTime();
    30     if ( mintime > post_time-pre_time ) mintime = post_time-pre_time;
    31   }
    32 
    33   double pre_time=currTime();
    34     preflow<ListGraph, int> max_flow_test(G, s, t, cap);
    35   double post_time=currTime();
    36     
    37   ListGraph::NodeMap<bool> cut(G);
    38   max_flow_test.minCut(cut); 
    39   int min_cut_value=0;
    40   for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
    41     if (cut.get(G.tail(e)) && !cut.get(G.head(e))) min_cut_value+=cap.get(e);
    42   }
    43 
    44   ListGraph::NodeMap<bool> cut1(G);
    45   max_flow_test.minMinCut(cut1); 
    46   int min_min_cut_value=0;
    47   for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
    48     if (cut.get(G.tail(e)) && !cut.get(G.head(e))) 
    49       min_min_cut_value+=cap.get(e);
    50   }
    51 
    52   ListGraph::NodeMap<bool> cut2(G);
    53   max_flow_test.maxMinCut(cut2); 
    54   int max_min_cut_value=0;
    55   for(EachEdgeIt e=G.first<EachEdgeIt>(); e.valid(); ++e) {
    56     if (cut2.get(G.tail(e)) && !cut2.get(G.head(e))) 
    57       max_min_cut_value+=cap.get(e);
    58       }
    59   
    60   std::cout << "min time of 10 runs: " << mintime << " sec"<< std::endl; 
    61   std::cout << "phase 0: " << max_flow_test.time-pre_time 
    62 	    << " sec"<< std::endl; 
    63   std::cout << "phase 1: " << post_time-max_flow_test.time 
    64 	    << " sec"<< std::endl; 
    65   std::cout << "flow value: "<< max_flow_test.maxFlow() << std::endl;
    66   std::cout << "min cut value: "<< min_cut_value << std::endl;
    67   std::cout << "min min cut value: "<< min_min_cut_value << std::endl;
    68   std::cout << "max min cut value: "<< max_min_cut_value << 
    69     std::endl<< std::endl;
    70   
    71   return 0;
    72 }