boost/libs/graph/test/weighted_matching_test.cpp

//=======================================================================
// Copyright (c) 2018 Yi Ji
//
// 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 <boost/graph/max_cardinality_matching.hpp>
#include <boost/graph/maximum_weighted_matching.hpp>

#include <iostream>
#include <fstream>
#include <sstream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/adjacency_matrix.hpp>
#include <boost/core/lightweight_test.hpp>

using namespace boost;

typedef property< edge_weight_t, float, property< edge_index_t, int > >
    EdgeProperty;

typedef adjacency_list< vecS, vecS, undirectedS,
    property< vertex_index_t, int >, EdgeProperty >
    undirected_graph;
typedef adjacency_list< listS, listS, undirectedS,
    property< vertex_index_t, int >, EdgeProperty >
    undirected_list_graph;
typedef adjacency_matrix< undirectedS, property< vertex_index_t, int >,
    EdgeProperty >
    undirected_adjacency_matrix_graph;

template < typename Graph > struct vertex_index_installer
{
    static void install(Graph&) {}
};

template <> struct vertex_index_installer< undirected_list_graph >
{
    static void install(undirected_list_graph& g)
    {
        typedef graph_traits< undirected_list_graph >::vertex_iterator
            vertex_iterator_t;
        typedef graph_traits< undirected_list_graph >::vertices_size_type
            v_size_t;

        vertex_iterator_t vi, vi_end;
        v_size_t i = 0;
        for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi, ++i)
            put(vertex_index, g, *vi, i);
    }
};

template < typename Graph > void print_graph(const Graph& g)
{
    typedef typename graph_traits< Graph >::edge_iterator edge_iterator_t;
    edge_iterator_t ei, ei_end;
    std::cout << std::endl << "The graph is: " << std::endl;
    for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei)
        std::cout << "add_edge(" << source(*ei, g) << ", " << target(*ei, g)
                  << ", EdgeProperty(" << get(edge_weight, g, *ei) << "), );"
                  << std::endl;
}

template < typename Graph >
void weighted_matching_test(const Graph& g,
    typename property_traits< typename property_map< Graph,
        edge_weight_t >::type >::value_type answer)
{
    typedef
        typename property_map< Graph, vertex_index_t >::type vertex_index_map_t;
    typedef vector_property_map<
        typename graph_traits< Graph >::vertex_descriptor, vertex_index_map_t >
        mate_t;
    mate_t mate(num_vertices(g));
    maximum_weighted_matching(g, mate);
    bool same_result = (matching_weight_sum(g, mate) == answer);
    BOOST_TEST(same_result);
    if (!same_result)
    {
        mate_t max_mate(num_vertices(g));
        brute_force_maximum_weighted_matching(g, max_mate);

        std::cout << std::endl
                  << "Found a weighted matching of weight sum "
                  << matching_weight_sum(g, mate) << std::endl
                  << "While brute-force search found a weighted matching of "
                     "weight sum "
                  << matching_weight_sum(g, max_mate) << std::endl;

        typedef
            typename graph_traits< Graph >::vertex_iterator vertex_iterator_t;
        vertex_iterator_t vi, vi_end;

        print_graph(g);

        std::cout << std::endl << "The algorithmic matching is:" << std::endl;
        for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
            if (mate[*vi] != graph_traits< Graph >::null_vertex()
                && *vi < mate[*vi])
                std::cout << "{" << *vi << ", " << mate[*vi] << "}"
                          << std::endl;

        std::cout << std::endl << "The brute-force matching is:" << std::endl;
        for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
            if (max_mate[*vi] != graph_traits< Graph >::null_vertex()
                && *vi < max_mate[*vi])
                std::cout << "{" << *vi << ", " << max_mate[*vi] << "}"
                          << std::endl;

        std::cout << std::endl;
    }
}

template < typename Graph >
Graph make_graph(typename graph_traits< Graph >::vertices_size_type num_v,
    typename graph_traits< Graph >::edges_size_type num_e,
    std::deque< std::size_t > input_edges)
{
    Graph g(num_v);
    vertex_index_installer< Graph >::install(g);
    for (std::size_t i = 0; i < num_e; ++i)
    {
        std::size_t src_v, tgt_v, edge_weight;
        src_v = input_edges.front();
        input_edges.pop_front();
        tgt_v = input_edges.front();
        input_edges.pop_front();
        edge_weight = input_edges.front();
        input_edges.pop_front();
        add_edge(
            vertex(src_v, g), vertex(tgt_v, g), EdgeProperty(edge_weight), g);
    }
    return g;
}

int main(int, char*[])
{
    std::ifstream in_file("weighted_matching.dat");
    std::string line;
    while (std::getline(in_file, line))
    {
        std::istringstream in_graph(line);
        std::size_t answer, num_v, num_e;
        in_graph >> answer >> num_v >> num_e;

        std::deque< std::size_t > input_edges;
        std::size_t i;
        while (in_graph >> i)
            input_edges.push_back(i);

        weighted_matching_test(
            make_graph< undirected_graph >(num_v, num_e, input_edges), answer);
        weighted_matching_test(
            make_graph< undirected_list_graph >(num_v, num_e, input_edges),
            answer);
        weighted_matching_test(make_graph< undirected_adjacency_matrix_graph >(
                                   num_v, num_e, input_edges),
            answer);
    }
    return boost::report_errors();
}