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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(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.
assert(checked_edmonds_maximum_cardinality_matching(g, &mate[0]));
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(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);
assert(checked_edmonds_maximum_cardinality_matching(g, &mate[0]));
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(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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