src/work/jacint/preflow_res_comp.cc
changeset 388 8aca0af3f30b
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/work/jacint/preflow_res_comp.cc	Fri Apr 23 21:26:32 2004 +0000
     1.3 @@ -0,0 +1,125 @@
     1.4 +/*
     1.5 +The only difference between preflow.h and preflow_res.h is that the latter
     1.6 +uses the ResGraphWrapper, while the first does not. (Bfs is implemented by
     1.7 +hand in both.) This test program runs Preflow and PreflowRes on the same
     1.8 +graph, tests the result of these implementations and writes the running time
     1.9 +of them.  */
    1.10 +#include <iostream>
    1.11 +
    1.12 +#include <smart_graph.h>
    1.13 +#include <dimacs.h>
    1.14 +#include <preflow.h>
    1.15 +#include <preflow_res.h>
    1.16 +#include <time_measure.h>
    1.17 +
    1.18 +using namespace hugo;
    1.19 +
    1.20 +int main(int, char **) {
    1.21 + 
    1.22 +  typedef SmartGraph Graph;
    1.23 +  
    1.24 +  typedef Graph::Node Node;
    1.25 +  typedef Graph::EdgeIt EdgeIt;
    1.26 +
    1.27 +  Graph G;
    1.28 +  Node s, t;
    1.29 +  Graph::EdgeMap<int> cap(G);
    1.30 +  readDimacsMaxFlow(std::cin, G, s, t, cap);
    1.31 +  Timer ts;
    1.32 +  
    1.33 +  std::cout <<
    1.34 +    "\n  In which way are we faster: using ResGraphWrapper or not?"
    1.35 +	    <<std::endl;
    1.36 +  std::cout <<
    1.37 +    "\n  Running preflow.h on a graph with " << 
    1.38 +    G.nodeNum() << " nodes and " << G.edgeNum() << " edges..."
    1.39 +	   << std::endl<<std::endl;
    1.40 +
    1.41 +
    1.42 +  
    1.43 +  Graph::EdgeMap<int> flow(G,0);
    1.44 +  Preflow<Graph, int> max_flow_test(G, s, t, cap, flow, 1);
    1.45 +  ts.reset();
    1.46 +  max_flow_test.run();
    1.47 +  std::cout << "Elapsed time NOT using the ResGraphWrapper: " << std::endl 
    1.48 +	    <<ts << std::endl;
    1.49 +  
    1.50 +  Graph::NodeMap<bool> mincut(G);
    1.51 +  max_flow_test.minMinCut(mincut); 
    1.52 +  int min_min_cut_value=0;
    1.53 +  EdgeIt e;
    1.54 +  for(G.first(e); G.valid(e); G.next(e)) {
    1.55 +    if (mincut[G.tail(e)] && !mincut[G.head(e)]) min_min_cut_value+=cap[e];
    1.56 +  }
    1.57 +
    1.58 +  Graph::NodeMap<bool> cut(G);
    1.59 +  max_flow_test.minCut(cut); 
    1.60 +  int min_cut_value=0;
    1.61 +  for(G.first(e); G.valid(e); G.next(e)) {
    1.62 +    if (cut[G.tail(e)] && !cut[G.head(e)]) 
    1.63 +      min_cut_value+=cap[e];
    1.64 +  }
    1.65 +
    1.66 +  Graph::NodeMap<bool> maxcut(G);
    1.67 +  max_flow_test.maxMinCut(maxcut); 
    1.68 +  int max_min_cut_value=0;
    1.69 +  for(G.first(e); G.valid(e); G.next(e)) {
    1.70 +    if (maxcut[G.tail(e)] && !maxcut[G.head(e)]) 
    1.71 +      max_min_cut_value+=cap[e];
    1.72 +      }
    1.73 +
    1.74 +  std::cout << "\n Checking the result: " <<std::endl;  
    1.75 +  std::cout << "Flow value: "<< max_flow_test.flowValue() << std::endl;
    1.76 +  std::cout << "Min cut value: "<< min_cut_value << std::endl;
    1.77 +  std::cout << "Min min cut value: "<< min_min_cut_value << std::endl;
    1.78 +  std::cout << "Max min cut value: "<< max_min_cut_value << 
    1.79 +    std::endl;
    1.80 +
    1.81 +  if ( max_flow_test.flowValue() == min_cut_value &&
    1.82 +       min_cut_value == min_min_cut_value &&
    1.83 +       min_min_cut_value == max_min_cut_value )
    1.84 +    std::cout << "They are equal! " <<std::endl<< std::endl<<"\n";  
    1.85 +  
    1.86 +  Graph::EdgeMap<int> flow2(G,0);
    1.87 +  PreflowRes<Graph, int> max_flow_test2(G, s, t, cap, flow2, 1);
    1.88 +  ts.reset();
    1.89 +  max_flow_test2.run();
    1.90 +  std::cout << "Elapsed time using the ResGraphWrapper: " << std::endl 
    1.91 +	    << ts << std::endl;
    1.92 +  
    1.93 +  Graph::NodeMap<bool> mincut2(G);
    1.94 +  max_flow_test2.minMinCut(mincut2); 
    1.95 +  int min_min_cut_value2=0;
    1.96 +    for(G.first(e); G.valid(e); G.next(e)) {
    1.97 +    if (mincut2[G.tail(e)] && !mincut2[G.head(e)]) min_min_cut_value2+=cap[e];
    1.98 +  }
    1.99 +
   1.100 +  Graph::NodeMap<bool> cut2(G);
   1.101 +  max_flow_test2.minCut(cut2); 
   1.102 +  int min_cut_value2=0;
   1.103 +  for(G.first(e); G.valid(e); G.next(e)) {
   1.104 +    if (cut2[G.tail(e)] && !cut2[G.head(e)]) 
   1.105 +      min_cut_value2+=cap[e];
   1.106 +  }
   1.107 +
   1.108 +  Graph::NodeMap<bool> maxcut2(G);
   1.109 +  max_flow_test2.maxMinCut(maxcut2); 
   1.110 +  int max_min_cut_value2=0;
   1.111 +  for(G.first(e); G.valid(e); G.next(e)) {
   1.112 +    if (maxcut2[G.tail(e)] && !maxcut2[G.head(e)]) 
   1.113 +      max_min_cut_value2+=cap[e];
   1.114 +      }
   1.115 +  
   1.116 +  std::cout << "\n Checking the result: " <<std::endl;  
   1.117 +  std::cout << "Flow value: "<< max_flow_test2.flowValue() << std::endl;
   1.118 +  std::cout << "Min cut value: "<< min_cut_value2 << std::endl;
   1.119 +  std::cout << "Min min cut value: "<< min_min_cut_value2 << std::endl;
   1.120 +  std::cout << "Max min cut value: "<< max_min_cut_value2 << 
   1.121 +    std::endl;  
   1.122 +  if ( max_flow_test.flowValue() == min_cut_value &&
   1.123 +       min_cut_value == min_min_cut_value &&
   1.124 +       min_min_cut_value == max_min_cut_value )
   1.125 +    std::cout << "They are equal! " <<std::endl<<"/n";  
   1.126 +  
   1.127 +  return 0;
   1.128 +}