src/test/max_matching_test.cc
author alpar
Tue, 18 Jan 2005 12:02:27 +0000
changeset 1086 caa13d291528
child 1092 36284b2500c3
permissions -rw-r--r--
In graphToEps(), nodes may have different shapes (circles or squares).
     1 /* -*- C++ -*-
     2  * src/test/max_matching_test.cc - Part of LEMON, a generic C++ optimization library
     3  *
     4  * Copyright (C) 2004 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     5  * (Egervary Combinatorial Optimization Research Group, EGRES).
     6  *
     7  * Permission to use, modify and distribute this software is granted
     8  * provided that this copyright notice appears in all copies. For
     9  * precise terms see the accompanying LICENSE file.
    10  *
    11  * This software is provided "AS IS" with no warranty of any kind,
    12  * express or implied, and with no claim as to its suitability for any
    13  * purpose.
    14  *
    15  */
    16 
    17 #include <iostream>
    18 #include <queue>
    19 #include <math.h>
    20 #include <cstdlib>
    21 
    22 #include "test_tools.h"
    23 #include <lemon/invalid.h>
    24 #include <lemon/list_graph.h>
    25 #include <graph_gen.h>
    26 #include <max_matching.h>
    27 
    28 using namespace std;
    29 using namespace lemon;
    30 
    31 int main() {
    32 
    33   typedef UndirListGraph Graph;
    34 
    35   typedef Graph::Edge Edge;
    36   typedef Graph::UndirEdgeIt UndirEdgeIt;
    37   typedef Graph::IncEdgeIt IncEdgeIt;
    38   typedef Graph::NodeIt NodeIt;
    39   typedef Graph::Node Node;
    40    
    41   Graph G;
    42 
    43   random_init(); 
    44   randomGraph(G, random(5000), random(20000) );  
    45 
    46   MaxMatching<Graph> max_matching(G);
    47   max_matching.runEdmonds(0);
    48   
    49   int s=0;
    50   Graph::NodeMap<Node> mate(G,INVALID);
    51   max_matching.writeNMapNode(mate);
    52   for(NodeIt v(G); v!=INVALID; ++v) {
    53     if ( mate[v]!=INVALID ) ++s;
    54   }
    55   int size=(int)s/2;  //size will be used as the size of a maxmatching
    56   
    57   check ( size == max_matching.size(), "mate() returns a different size matching than max_matching.size()" );
    58 
    59   Graph::NodeMap<MaxMatching<Graph>::pos_enum> pos0(G);
    60   max_matching.writePos(pos0);
    61   
    62   max_matching.resetPos();
    63   max_matching.resetMatching();
    64   max_matching.runEdmonds(1);
    65   s=0;
    66   max_matching.writeNMapNode(mate);
    67   for(NodeIt v(G); v!=INVALID; ++v) {
    68     if ( mate[v]!=INVALID ) ++s;
    69   }
    70   check ( (int)s/2 == size, "The size does not equal!" );
    71 
    72   Graph::NodeMap<MaxMatching<Graph>::pos_enum> pos1(G);
    73   max_matching.writePos(pos1);
    74 
    75   max_matching.resetPos();
    76   max_matching.run();
    77   s=0;
    78   max_matching.writeNMapNode(mate);
    79   for(NodeIt v(G); v!=INVALID; ++v) {
    80     if ( mate[v]!=INVALID ) ++s;
    81   }
    82   check ( (int)s/2 == size, "The size does not equal!" ); 
    83   
    84   Graph::NodeMap<MaxMatching<Graph>::pos_enum> pos2(G);
    85   max_matching.writePos(pos2);
    86 
    87   max_matching.resetPos();
    88   max_matching.resetMatching();
    89   max_matching.run();
    90   s=0;
    91   max_matching.writeNMapNode(mate);
    92   for(NodeIt v(G); v!=INVALID; ++v) {
    93     if ( mate[v]!=INVALID ) ++s;
    94   }
    95   check ( (int)s/2 == size, "The size does not equal!" ); 
    96   
    97   Graph::NodeMap<MaxMatching<Graph>::pos_enum> pos(G);
    98   max_matching.writePos(pos);
    99    
   100   bool ismatching=true;
   101   for(NodeIt v(G); v!=INVALID; ++v) {
   102     if ( mate[v]!=INVALID ) {
   103       Node u=mate[v];
   104       if (mate[u]!=v) ismatching=false; 
   105     }
   106   }  
   107   check ( ismatching, "It is not a matching!" );
   108 
   109   bool coincide=true;
   110   for(NodeIt v(G); v!=INVALID; ++v) {
   111    if ( pos0[v] != pos1[v] || pos1[v]!=pos2[v] || pos2[v]!=pos[v] ) {
   112      coincide=false;
   113     }
   114   }
   115   check ( coincide, "The decompositions do not coincide! " );
   116 
   117   bool noedge=true;
   118   for(UndirEdgeIt e(G); e!=INVALID; ++e) {
   119    if ( (pos[G.target(e)]==max_matching.C && pos[G.source(e)]==max_matching.D) || 
   120 	 (pos[G.target(e)]==max_matching.D && pos[G.source(e)]==max_matching.C) )
   121       noedge=false; 
   122   }
   123   check ( noedge, "There are edges between D and C!" );
   124   
   125   bool oddcomp=true;
   126   Graph::NodeMap<bool> todo(G,true);
   127   int num_comp=0;
   128   for(NodeIt v(G); v!=INVALID; ++v) {
   129    if ( pos[v]==max_matching.D && todo[v] ) {
   130       int comp_size=1;
   131       ++num_comp;
   132       std::queue<Node> Q;
   133       Q.push(v);
   134       todo.set(v,false);
   135       while (!Q.empty()) {
   136 	Node w=Q.front();	
   137 	Q.pop();
   138 	for(IncEdgeIt e(G,w); e!=INVALID; ++e) {
   139 	  Node u=G.target(e);
   140 	  if ( pos[u]==max_matching.D && todo[u] ) {
   141 	    ++comp_size;
   142 	    Q.push(u);
   143 	    todo.set(u,false);
   144 	  }
   145 	}
   146       }
   147       if ( !(comp_size % 2) ) oddcomp=false;  
   148     }
   149   }
   150   check ( oddcomp, "A component of G[D] is not odd." );
   151 
   152   int barrier=0;
   153   for(NodeIt v(G); v!=INVALID; ++v) {
   154     if ( pos[v]==max_matching.A ) ++barrier;
   155   }
   156   int expected_size=(int)( countNodes(G)-num_comp+barrier)/2;
   157   check ( size==expected_size, "The size of the matching is wrong." );
   158   
   159   return 0;
   160 }
   161 
   162 
   163 void random_init()
   164 {
   165   unsigned int seed = getpid();
   166   seed |= seed << 15;
   167   seed ^= time(0);
   168   
   169   srand(seed);
   170 }
   171 
   172 
   173 int random(int m)
   174 {
   175   return int( double(m) * rand() / (RAND_MAX + 1.0) );
   176 }
   177 
   178 
   179 /// Generates a random graph with n nodes and m edges.
   180 /// Before generating the random graph, \c g.clear() is called.
   181 template<typename Graph>
   182 void randomGraph(Graph& g, int n, int m) {
   183   g.clear();
   184   std::vector<typename Graph::Node> nodes;
   185   for (int i=0; i<n; ++i)
   186     nodes.push_back(g.addNode());
   187   for (int i=0; i<m; ++i) 
   188     g.addEdge(nodes[random(n)], nodes[random(n)]);
   189 }