source: downloads/boost_1_34_1/libs/graph/test/random_matching_test.cpp @ 30

//=======================================================================
// Copyright (c) 2005 Aaron Windsor
//
// Distributed under the Boost Software License, Version 1.0. 
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
//=======================================================================
#include <cstdlib>
#include <iostream>
#include <boost/vector_property_map.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/random.hpp>
#include <ctime>
#include <boost/random.hpp>

#include <boost/graph/max_cardinality_matching.hpp>

using namespace boost;

typedef adjacency_list<vecS, 
                       vecS, 
                       undirectedS, 
                       property<vertex_index_t, int> >  undirected_graph;

typedef property_map<undirected_graph,vertex_index_t>::type vertex_index_map_t;
typedef vector_property_map<graph_traits<undirected_graph>::vertex_descriptor, vertex_index_map_t > mate_t;
typedef graph_traits<undirected_graph>::vertex_iterator vertex_iterator_t;
typedef graph_traits<undirected_graph>::vertex_descriptor vertex_descriptor_t;
typedef graph_traits<undirected_graph>::vertices_size_type v_size_t;


int main(int argc, char** argv)
{  
  if (argc < 3)
    {
      std::cout << "Usage: " << argv[0] << " n m" << std::endl
                << "Tests the checked matching on a random graph w/ n vertices and m edges" << std::endl;
      exit(-1);
    }
  
  int n = atoi(argv[1]);
  int m = atoi(argv[2]);

  undirected_graph g(n);
  

  typedef boost::mt19937 base_generator_type;
  base_generator_type generator(static_cast<unsigned int>(std::time(0)));
  boost::uniform_int<> distribution(0, n-1);
  boost::variate_generator<base_generator_type&, boost::uniform_int<> > rand_num(generator, distribution);

  int num_edges = 0;
  bool success;

  while (num_edges < m)
    {
      vertex_descriptor_t u = random_vertex(g,rand_num);
      vertex_descriptor_t v = random_vertex(g,rand_num);
      if (u != v)
        {
          if (!edge(u,v,g).second)
            tie(tuples::ignore, success) = add_edge(u, v, g);
          else
            success = false;

          if (success)
            num_edges++;
        }
    }

  mate_t mate(n);
  bool random_graph_result = checked_edmonds_maximum_cardinality_matching(g,mate);  
 
  if (!random_graph_result)
    {
      std::cout << "TEST 1 FAILED!!!" << std::endl << std::endl;

      std::cout << "Graph has edges: ";
      typedef graph_traits<undirected_graph>::edge_iterator edge_iterator_t;
      edge_iterator_t ei,ei_end;
      for(tie(ei,ei_end) = edges(g); ei != ei_end; ++ei)
        std:: cout << *ei << ", ";
      std::cout << std::endl;
      
      std::cout << "Matching is: ";
      vertex_iterator_t vi, vi_end;
      for(tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
        if (mate[*vi] != graph_traits<undirected_graph>::null_vertex() &&
            *vi < mate[*vi])
          std::cout << "{" << *vi << "," << mate[*vi] << "}, ";
      std::cout << std::endl;
    }

  //Now remove an edge from the random_mate matching.
  vertex_iterator_t vi, vi_end;
  for(tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
    if (mate[*vi] != graph_traits<undirected_graph>::null_vertex())
      break;
  
  mate[mate[*vi]] = graph_traits<undirected_graph>::null_vertex();
  mate[*vi] = graph_traits<undirected_graph>::null_vertex();
  
  //...and run the matching verifier - it should tell us that the matching isn't
  //a maximum matching.
  bool modified_random_verification_result =
    maximum_cardinality_matching_verifier<undirected_graph,mate_t,vertex_index_map_t>::verify_matching(g,mate,get(vertex_index,g));
  
  if (modified_random_verification_result)
    {
      std::cout << "TEST 2 FAILED!!!" << std::endl;
    }

  //find a greedy matching on the graph
  mate_t greedy_mate(n);
  greedy_matching<undirected_graph, mate_t>::find_matching(g,greedy_mate);

  if (matching_size(g,mate) > matching_size(g,greedy_mate) &&
      maximum_cardinality_matching_verifier<undirected_graph,mate_t,vertex_index_map_t>::verify_matching(g,greedy_mate,get(vertex_index,g)))
        std::cout << "TEST 3 FAILED!!!" << std::endl;

  return 0;
}