Boost C++ Libraries

libs/graph/example/kuratowski_subgraph.cpp

//=======================================================================
// Copyright 2007 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 <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/properties.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/property_map/property_map.hpp>
#include <boost/ref.hpp>
#include <vector>

#include <boost/graph/boyer_myrvold_planar_test.hpp>
#include <boost/graph/is_kuratowski_subgraph.hpp>

using namespace boost;

int main(int argc, char** argv)
{

    typedef adjacency_list< vecS, vecS, undirectedS,
        property< vertex_index_t, int >, property< edge_index_t, int > >
        graph;

    // Create a K_6 (complete graph on 6 vertices), which
    // contains both Kuratowski subgraphs as minors.
    graph g(6);
    add_edge(0, 1, g);
    add_edge(0, 2, g);
    add_edge(0, 3, g);
    add_edge(0, 4, g);
    add_edge(0, 5, g);
    add_edge(1, 2, g);
    add_edge(1, 3, g);
    add_edge(1, 4, g);
    add_edge(1, 5, g);
    add_edge(2, 3, g);
    add_edge(2, 4, g);
    add_edge(2, 5, g);
    add_edge(3, 4, g);
    add_edge(3, 5, g);
    add_edge(4, 5, g);

    // Initialize the interior edge index
    property_map< graph, edge_index_t >::type e_index = get(edge_index, g);
    graph_traits< graph >::edges_size_type edge_count = 0;
    graph_traits< graph >::edge_iterator ei, ei_end;
    for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei)
        put(e_index, *ei, edge_count++);

    // Test for planarity - we know it is not planar, we just want to
    // compute the kuratowski subgraph as a side-effect
    typedef std::vector< graph_traits< graph >::edge_descriptor >
        kuratowski_edges_t;
    kuratowski_edges_t kuratowski_edges;
    if (boyer_myrvold_planarity_test(boyer_myrvold_params::graph = g,
            boyer_myrvold_params::kuratowski_subgraph
            = std::back_inserter(kuratowski_edges)))
        std::cout << "Input graph is planar" << std::endl;
    else
    {
        std::cout << "Input graph is not planar" << std::endl;

        std::cout << "Edges in the Kuratowski subgraph: ";
        kuratowski_edges_t::iterator ki, ki_end;
        ki_end = kuratowski_edges.end();
        for (ki = kuratowski_edges.begin(); ki != ki_end; ++ki)
        {
            std::cout << *ki << " ";
        }
        std::cout << std::endl;

        std::cout << "Is a kuratowski subgraph? ";
        if (is_kuratowski_subgraph(
                g, kuratowski_edges.begin(), kuratowski_edges.end()))
            std::cout << "Yes." << std::endl;
        else
            std::cout << "No." << std::endl;
    }

    return 0;
}