src/work/jacint/preflow_res_comp.cc
changeset 444 618c5d6f36b9
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-1:000000000000 0:9979f10f62bb
       
     1 /*
       
     2 The only difference between preflow.h and preflow_res.h is that the latter
       
     3 uses the ResGraphWrapper, while the first does not. (Bfs is implemented by
       
     4 hand in both.) This test program runs Preflow and PreflowRes on the same
       
     5 graph, tests the result of these implementations and writes the running time
       
     6 of them.  */
       
     7 #include <iostream>
       
     8 
       
     9 #include <smart_graph.h>
       
    10 #include <dimacs.h>
       
    11 #include <preflow.h>
       
    12 #include <preflow_res.h>
       
    13 #include <time_measure.h>
       
    14 
       
    15 using namespace hugo;
       
    16 
       
    17 int main(int, char **) {
       
    18  
       
    19   typedef SmartGraph Graph;
       
    20   
       
    21   typedef Graph::Node Node;
       
    22   typedef Graph::EdgeIt EdgeIt;
       
    23 
       
    24   Graph G;
       
    25   Node s, t;
       
    26   Graph::EdgeMap<int> cap(G);
       
    27   readDimacsMaxFlow(std::cin, G, s, t, cap);
       
    28   Timer ts;
       
    29   
       
    30   std::cout <<
       
    31     "\n  In which way are we faster: using ResGraphWrapper or not?"
       
    32 	    <<std::endl;
       
    33   std::cout <<
       
    34     "\n  Running preflow.h on a graph with " << 
       
    35     G.nodeNum() << " nodes and " << G.edgeNum() << " edges..."
       
    36 	   << std::endl<<std::endl;
       
    37 
       
    38 
       
    39   
       
    40   Graph::EdgeMap<int> flow(G,0);
       
    41   Preflow<Graph, int> max_flow_test(G, s, t, cap, flow, 1);
       
    42   ts.reset();
       
    43   max_flow_test.run();
       
    44   std::cout << "Elapsed time NOT using the ResGraphWrapper: " << std::endl 
       
    45 	    <<ts << std::endl;
       
    46   
       
    47   Graph::NodeMap<bool> mincut(G);
       
    48   max_flow_test.minMinCut(mincut); 
       
    49   int min_min_cut_value=0;
       
    50   EdgeIt e;
       
    51   for(G.first(e); G.valid(e); G.next(e)) {
       
    52     if (mincut[G.tail(e)] && !mincut[G.head(e)]) min_min_cut_value+=cap[e];
       
    53   }
       
    54 
       
    55   Graph::NodeMap<bool> cut(G);
       
    56   max_flow_test.minCut(cut); 
       
    57   int min_cut_value=0;
       
    58   for(G.first(e); G.valid(e); G.next(e)) {
       
    59     if (cut[G.tail(e)] && !cut[G.head(e)]) 
       
    60       min_cut_value+=cap[e];
       
    61   }
       
    62 
       
    63   Graph::NodeMap<bool> maxcut(G);
       
    64   max_flow_test.maxMinCut(maxcut); 
       
    65   int max_min_cut_value=0;
       
    66   for(G.first(e); G.valid(e); G.next(e)) {
       
    67     if (maxcut[G.tail(e)] && !maxcut[G.head(e)]) 
       
    68       max_min_cut_value+=cap[e];
       
    69       }
       
    70 
       
    71   std::cout << "\n Checking the result: " <<std::endl;  
       
    72   std::cout << "Flow value: "<< max_flow_test.flowValue() << std::endl;
       
    73   std::cout << "Min cut value: "<< min_cut_value << std::endl;
       
    74   std::cout << "Min min cut value: "<< min_min_cut_value << std::endl;
       
    75   std::cout << "Max min cut value: "<< max_min_cut_value << 
       
    76     std::endl;
       
    77 
       
    78   if ( max_flow_test.flowValue() == min_cut_value &&
       
    79        min_cut_value == min_min_cut_value &&
       
    80        min_min_cut_value == max_min_cut_value )
       
    81     std::cout << "They are equal! " <<std::endl<< std::endl<<"\n";  
       
    82   
       
    83   Graph::EdgeMap<int> flow2(G,0);
       
    84   PreflowRes<Graph, int> max_flow_test2(G, s, t, cap, flow2, 1);
       
    85   ts.reset();
       
    86   max_flow_test2.run();
       
    87   std::cout << "Elapsed time using the ResGraphWrapper: " << std::endl 
       
    88 	    << ts << std::endl;
       
    89   
       
    90   Graph::NodeMap<bool> mincut2(G);
       
    91   max_flow_test2.minMinCut(mincut2); 
       
    92   int min_min_cut_value2=0;
       
    93     for(G.first(e); G.valid(e); G.next(e)) {
       
    94     if (mincut2[G.tail(e)] && !mincut2[G.head(e)]) min_min_cut_value2+=cap[e];
       
    95   }
       
    96 
       
    97   Graph::NodeMap<bool> cut2(G);
       
    98   max_flow_test2.minCut(cut2); 
       
    99   int min_cut_value2=0;
       
   100   for(G.first(e); G.valid(e); G.next(e)) {
       
   101     if (cut2[G.tail(e)] && !cut2[G.head(e)]) 
       
   102       min_cut_value2+=cap[e];
       
   103   }
       
   104 
       
   105   Graph::NodeMap<bool> maxcut2(G);
       
   106   max_flow_test2.maxMinCut(maxcut2); 
       
   107   int max_min_cut_value2=0;
       
   108   for(G.first(e); G.valid(e); G.next(e)) {
       
   109     if (maxcut2[G.tail(e)] && !maxcut2[G.head(e)]) 
       
   110       max_min_cut_value2+=cap[e];
       
   111       }
       
   112   
       
   113   std::cout << "\n Checking the result: " <<std::endl;  
       
   114   std::cout << "Flow value: "<< max_flow_test2.flowValue() << std::endl;
       
   115   std::cout << "Min cut value: "<< min_cut_value2 << std::endl;
       
   116   std::cout << "Min min cut value: "<< min_min_cut_value2 << std::endl;
       
   117   std::cout << "Max min cut value: "<< max_min_cut_value2 << 
       
   118     std::endl;  
       
   119   if ( max_flow_test.flowValue() == min_cut_value &&
       
   120        min_cut_value == min_min_cut_value &&
       
   121        min_min_cut_value == max_min_cut_value )
       
   122     std::cout << "They are equal! " <<std::endl<<"/n";  
       
   123   
       
   124   return 0;
       
   125 }