| //======================================================================= |
| // 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. |
| |
| 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(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(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; |
| } |