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//=======================================================================
// 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 <string>
#include <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <cassert>
#include <boost/graph/max_cardinality_matching.hpp>
using namespace boost;
typedef adjacency_list< vecS, vecS, undirectedS > my_graph;
int main()
{
// Create the following graph: (it'll look better when output
// to the terminal in a fixed width font...)
const int n_vertices = 18;
std::vector< std::string > ascii_graph;
ascii_graph.push_back(" 0 1---2 3 ");
ascii_graph.push_back(" \\ / \\ / ");
ascii_graph.push_back(" 4---5 6---7 ");
ascii_graph.push_back(" | | | | ");
ascii_graph.push_back(" 8---9 10---11 ");
ascii_graph.push_back(" / \\ / \\ ");
ascii_graph.push_back(" 12 13 14---15 16 17 ");
// It has a perfect matching of size 8. There are two isolated
// vertices that we'll use later...
my_graph g(n_vertices);
// our vertices are stored in a vector, so we can refer to vertices
// by integers in the range 0..15
add_edge(1, 2, g);
add_edge(0, 4, g);
add_edge(1, 5, g);
add_edge(2, 6, g);
add_edge(3, 7, g);
add_edge(4, 5, g);
add_edge(6, 7, g);
add_edge(4, 8, g);
add_edge(5, 9, g);
add_edge(6, 10, g);
add_edge(7, 11, g);
add_edge(8, 9, g);
add_edge(10, 11, g);
add_edge(8, 13, g);
add_edge(9, 14, g);
add_edge(10, 15, g);
add_edge(11, 16, g);
add_edge(14, 15, g);
std::vector< graph_traits< my_graph >::vertex_descriptor > mate(n_vertices);
// find the maximum cardinality matching. we'll use a checked version
// of the algorithm, which takes a little longer than the unchecked
// version, but has the advantage that it will return "false" if the
// matching returned is not actually a maximum cardinality matching
// in the graph.
bool success = checked_edmonds_maximum_cardinality_matching(g, &mate[0]);
assert(success);
std::cout << "In the following graph:" << std::endl << std::endl;
for (std::vector< std::string >::iterator itr = ascii_graph.begin();
itr != ascii_graph.end(); ++itr)
std::cout << *itr << std::endl;
std::cout << std::endl
<< "Found a matching of size " << matching_size(g, &mate[0])
<< std::endl;
std::cout << "The matching is:" << std::endl;
graph_traits< my_graph >::vertex_iterator vi, vi_end;
for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
if (mate[*vi] != graph_traits< my_graph >::null_vertex()
&& *vi < mate[*vi])
std::cout << "{" << *vi << ", " << mate[*vi] << "}" << std::endl;
std::cout << std::endl;
// now we'll add two edges, and the perfect matching has size 9
ascii_graph.pop_back();
ascii_graph.push_back(" 12---13 14---15 16---17 ");
add_edge(12, 13, g);
add_edge(16, 17, g);
success = checked_edmonds_maximum_cardinality_matching(g, &mate[0]);
assert(success);
std::cout << "In the following graph:" << std::endl << std::endl;
for (std::vector< std::string >::iterator itr = ascii_graph.begin();
itr != ascii_graph.end(); ++itr)
std::cout << *itr << std::endl;
std::cout << std::endl
<< "Found a matching of size " << matching_size(g, &mate[0])
<< std::endl;
std::cout << "The matching is:" << std::endl;
for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
if (mate[*vi] != graph_traits< my_graph >::null_vertex()
&& *vi < mate[*vi])
std::cout << "{" << *vi << ", " << mate[*vi] << "}" << std::endl;
return 0;
}
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