119 lines
3.8 KiB
C++
119 lines
3.8 KiB
C++
//=======================================================================
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// Copyright (c) 2005 Aaron Windsor
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//
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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//=======================================================================
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#include <string>
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#include <iostream>
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#include <boost/graph/adjacency_list.hpp>
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#include <cassert>
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#include <boost/graph/max_cardinality_matching.hpp>
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using namespace boost;
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typedef adjacency_list<vecS, vecS, undirectedS> my_graph;
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int main()
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{
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// Create the following graph: (it'll look better when output
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// to the terminal in a fixed width font...)
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const int n_vertices = 18;
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std::vector<std::string> ascii_graph;
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ascii_graph.push_back(" 0 1---2 3 ");
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ascii_graph.push_back(" \\ / \\ / ");
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ascii_graph.push_back(" 4---5 6---7 ");
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ascii_graph.push_back(" | | | | ");
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ascii_graph.push_back(" 8---9 10---11 ");
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ascii_graph.push_back(" / \\ / \\ ");
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ascii_graph.push_back(" 12 13 14---15 16 17 ");
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// It has a perfect matching of size 8. There are two isolated
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// vertices that we'll use later...
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my_graph g(n_vertices);
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// our vertices are stored in a vector, so we can refer to vertices
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// by integers in the range 0..15
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add_edge(1,2,g);
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add_edge(0,4,g);
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add_edge(1,5,g);
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add_edge(2,6,g);
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add_edge(3,7,g);
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add_edge(4,5,g);
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add_edge(6,7,g);
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add_edge(4,8,g);
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add_edge(5,9,g);
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add_edge(6,10,g);
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add_edge(7,11,g);
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add_edge(8,9,g);
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add_edge(10,11,g);
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add_edge(8,13,g);
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add_edge(9,14,g);
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add_edge(10,15,g);
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add_edge(11,16,g);
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add_edge(14,15,g);
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std::vector<graph_traits<my_graph>::vertex_descriptor> mate(n_vertices);
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// find the maximum cardinality matching. we'll use a checked version
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// of the algorithm, which takes a little longer than the unchecked
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// version, but has the advantage that it will return "false" if the
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// matching returned is not actually a maximum cardinality matching
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// in the graph.
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bool success = checked_edmonds_maximum_cardinality_matching(g, &mate[0]);
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assert(success);
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std::cout << "In the following graph:" << std::endl << std::endl;
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for(std::vector<std::string>::iterator itr = ascii_graph.begin(); itr != ascii_graph.end(); ++itr)
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std::cout << *itr << std::endl;
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std::cout << std::endl << "Found a matching of size " << matching_size(g, &mate[0]) << std::endl;
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std::cout << "The matching is:" << std::endl;
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graph_traits<my_graph>::vertex_iterator vi, vi_end;
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for(boost::tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
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if (mate[*vi] != graph_traits<my_graph>::null_vertex() && *vi < mate[*vi])
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std::cout << "{" << *vi << ", " << mate[*vi] << "}" << std::endl;
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std::cout << std::endl;
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//now we'll add two edges, and the perfect matching has size 9
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ascii_graph.pop_back();
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ascii_graph.push_back(" 12---13 14---15 16---17 ");
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add_edge(12,13,g);
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add_edge(16,17,g);
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success = checked_edmonds_maximum_cardinality_matching(g, &mate[0]);
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assert(success);
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std::cout << "In the following graph:" << std::endl << std::endl;
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for(std::vector<std::string>::iterator itr = ascii_graph.begin(); itr != ascii_graph.end(); ++itr)
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std::cout << *itr << std::endl;
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std::cout << std::endl << "Found a matching of size " << matching_size(g, &mate[0]) << std::endl;
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std::cout << "The matching is:" << std::endl;
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for(boost::tie(vi,vi_end) = vertices(g); vi != vi_end; ++vi)
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if (mate[*vi] != graph_traits<my_graph>::null_vertex() && *vi < mate[*vi])
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std::cout << "{" << *vi << ", " << mate[*vi] << "}" << std::endl;
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return 0;
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}
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