Boost C++ Libraries

libs/graph/example/canonical_ordering.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/planar_canonical_ordering.hpp>
#include <boost/graph/boyer_myrvold_planar_test.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 maximal planar graph on 6 vertices
    graph g(6);

    add_edge(0, 1, g);
    add_edge(1, 2, g);
    add_edge(2, 3, g);
    add_edge(3, 4, g);
    add_edge(4, 5, g);
    add_edge(5, 0, g);

    add_edge(0, 2, g);
    add_edge(0, 3, g);
    add_edge(0, 4, g);

    add_edge(1, 3, g);
    add_edge(1, 4, g);
    add_edge(1, 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 planar, we just want to
    // compute the planar embedding as a side-effect
    typedef std::vector< graph_traits< graph >::edge_descriptor > vec_t;
    std::vector< vec_t > embedding(num_vertices(g));
    if (boyer_myrvold_planarity_test(boyer_myrvold_params::graph = g,
            boyer_myrvold_params::embedding = make_iterator_property_map(
                embedding.begin(), get(vertex_index, g))))
        std::cout << "Input graph is planar" << std::endl;
    else
        std::cout << "Input graph is not planar" << std::endl;

    typedef std::vector< graph_traits< graph >::vertex_descriptor >
        ordering_storage_t;

    ordering_storage_t ordering;
    planar_canonical_ordering(g,
        make_iterator_property_map(embedding.begin(), get(vertex_index, g)),
        std::back_inserter(ordering));

    ordering_storage_t::iterator oi, oi_end;
    oi_end = ordering.end();
    std::cout << "The planar canonical ordering is: ";
    for (oi = ordering.begin(); oi != oi_end; ++oi)
        std::cout << *oi << " ";
    std::cout << std::endl;

    return 0;
}