126 lines
4.1 KiB
C++
126 lines
4.1 KiB
C++
//=======================================================================
|
|
// 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;
|
|
}
|