src/test/preflow_test.cc
author marci
Mon, 20 Sep 2004 16:20:11 +0000
changeset 889 47bb9b8f5705
parent 880 9d0bfd35b97c
child 906 17f31d280385
permissions -rwxr-xr-x
EXAMPLE_PATH is set to the demo dir.
     1 #include <fstream>
     2 #include <string>
     3 
     4 #include "test_tools.h"
     5 #include <hugo/smart_graph.h>
     6 #include <hugo/dimacs.h>
     7 #include <hugo/preflow.h>
     8 #include <hugo/skeletons/graph.h>
     9 #include <hugo/skeletons/maps.h>
    10 
    11 using namespace hugo;
    12 
    13 void check_Preflow() 
    14 {
    15   typedef int VType;
    16   typedef skeleton::StaticGraph Graph;
    17 
    18   typedef Graph::Node Node;
    19   typedef Graph::Edge Edge;
    20   typedef skeleton::ReadMap<Edge,VType> CapMap;
    21   typedef skeleton::ReadWriteMap<Edge,VType> FlowMap;
    22   typedef skeleton::ReadWriteMap<Node,bool> CutMap;
    23  
    24   typedef Preflow<Graph, int, CapMap, FlowMap> PType;
    25 
    26   Graph G;
    27   Node n;
    28   CapMap cap;
    29   FlowMap flow;
    30   CutMap cut;
    31 
    32   PType preflow_test(G,n,n,cap,flow);
    33 
    34   preflow_test.run();
    35   preflow_test.flowValue();
    36   preflow_test.setSource(n);
    37   preflow_test.setFlow(flow);
    38 
    39   preflow_test.phase1(PType::NO_FLOW);
    40   preflow_test.minCut(cut);
    41 
    42   preflow_test.phase2();
    43   preflow_test.setTarget(n);
    44   preflow_test.setCap(cap);
    45   preflow_test.minMinCut(cut);
    46   preflow_test.maxMinCut(cut);
    47 }
    48 
    49 int cut_value ( SmartGraph& G, SmartGraph::NodeMap<bool>& cut, 
    50 		SmartGraph::EdgeMap<int>& cap) {
    51   
    52   int c=0;
    53   for(SmartGraph::EdgeIt e(G); e!=INVALID; ++e) {
    54     if (cut[G.tail(e)] && !cut[G.head(e)]) c+=cap[e];
    55   }
    56   return c;
    57 }
    58 
    59 int main() {
    60 
    61   typedef SmartGraph Graph;
    62   
    63   typedef Graph::Node Node;
    64   typedef Graph::NodeIt NodeIt;
    65   typedef Graph::EdgeIt EdgeIt;
    66   typedef Graph::EdgeMap<int> CapMap;
    67   typedef Graph::EdgeMap<int> FlowMap;
    68   typedef Graph::NodeMap<bool> CutMap;
    69 
    70   typedef Preflow<Graph, int> PType;
    71 
    72   std::string f_name;
    73   if( getenv("srcdir") ) {
    74     f_name = std::string(getenv("srcdir")) + "/preflow_graph.dim";
    75   }
    76   else {
    77     f_name = "preflow_graph.dim";
    78   }
    79   
    80   std::ifstream file(f_name.c_str());
    81   
    82   check(file, "Input file '" << f_name << "' not found.");
    83   
    84   Graph G;
    85   Node s, t;
    86   CapMap cap(G);
    87   readDimacs(file, G, cap, s, t);
    88 
    89   FlowMap flow(G,0);
    90 
    91  
    92 
    93   PType preflow_test(G, s, t, cap, flow);
    94   preflow_test.run(PType::ZERO_FLOW);
    95     
    96   CutMap mincut(G,false);
    97   preflow_test.minCut(mincut); 
    98   int min_cut_value=cut_value(G,mincut,cap);
    99    
   100   CutMap minmincut(G,false);
   101   preflow_test.minMinCut(minmincut); 
   102   int min_min_cut_value=cut_value(G,minmincut,cap);
   103    
   104   CutMap maxmincut(G,false);
   105   preflow_test.maxMinCut(maxmincut); 
   106   int max_min_cut_value=cut_value(G,maxmincut,cap);
   107 
   108   check(preflow_test.flowValue() == min_cut_value &&
   109 	min_cut_value == min_min_cut_value &&
   110 	min_min_cut_value == max_min_cut_value,
   111 	"The max flow value is not equal to the three min cut values.");
   112 
   113   int flow_value=preflow_test.flowValue();
   114 
   115 
   116 
   117   for(EdgeIt e(G); e!=INVALID; ++e) cap[e]=2*cap[e]; 
   118   preflow_test.setCap(cap);  
   119 
   120   preflow_test.phase1(PType::PRE_FLOW);
   121 
   122   CutMap mincut1(G,false);
   123   preflow_test.minCut(mincut1); 
   124   min_cut_value=cut_value(G,mincut1,cap);
   125    
   126   check(preflow_test.flowValue() == min_cut_value &&
   127 	min_cut_value == 2*flow_value,
   128 	"The max flow value or the min cut value is wrong.");
   129 
   130   preflow_test.phase2();
   131 
   132   CutMap mincut2(G,false);
   133   preflow_test.minCut(mincut2); 
   134   min_cut_value=cut_value(G,mincut2,cap);
   135    
   136   CutMap minmincut2(G,false);
   137   preflow_test.minMinCut(minmincut2); 
   138   min_min_cut_value=cut_value(G,minmincut2,cap);
   139  
   140   preflow_test.maxMinCut(maxmincut); 
   141   max_min_cut_value=cut_value(G,maxmincut,cap);
   142 
   143   check(preflow_test.flowValue() == min_cut_value &&
   144 	min_cut_value == min_min_cut_value &&
   145 	min_min_cut_value == max_min_cut_value &&
   146 	min_cut_value == 2*flow_value,
   147 	"The max flow value or the three min cut values were not doubled");
   148 
   149 
   150 
   151   EdgeIt e(G);
   152   for( int i=1; i==10; ++i ) {
   153     flow.set(e,0);
   154     ++e;
   155   }
   156 
   157   preflow_test.setFlow(flow); 
   158 
   159   NodeIt tmp1(G,s);
   160   ++tmp1;
   161   if ( tmp1 != INVALID ) s=tmp1;
   162 
   163   NodeIt tmp2(G,t);
   164   ++tmp2;
   165   if ( tmp2 != INVALID ) t=tmp2;
   166 
   167   preflow_test.setSource(s);
   168   preflow_test.setTarget(t); 
   169   
   170   preflow_test.run();
   171 
   172   CutMap mincut3(G,false);
   173   preflow_test.minCut(mincut3); 
   174   min_cut_value=cut_value(G,mincut3,cap);
   175    
   176   CutMap minmincut3(G,false);
   177   preflow_test.minMinCut(minmincut3); 
   178   min_min_cut_value=cut_value(G,minmincut3,cap);
   179    
   180   preflow_test.maxMinCut(maxmincut); 
   181   max_min_cut_value=cut_value(G,maxmincut,cap);
   182 
   183   check(preflow_test.flowValue() == min_cut_value &&
   184 	min_cut_value == min_min_cut_value &&
   185 	min_min_cut_value == max_min_cut_value,
   186 	"The max flow value or the three min cut values are incorrect.");
   187 }