graph/test/subgraph.cpp

//  (C) Copyright Jeremy Siek 2004
//  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 <set>

#include <boost/core/lightweight_test.hpp>

#include <boost/graph/subgraph.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/random.hpp>
#include "graph_test.hpp"
#include <boost/graph/iteration_macros.hpp>
#include <boost/random/mersenne_twister.hpp>

#include "test_graph.hpp"

// UNDER CONSTRUCTION

// This is a helper function to recusively compare two subgraphs,
// including the index for every local edges and their children.
template < typename subgraph_t >
void sub_cmp(subgraph_t const& g1, subgraph_t const& g2)
{
    BOOST_TEST(g1.is_root() == g2.is_root());
    BOOST_TEST(num_vertices(g1) == num_vertices(g2));
    BOOST_TEST(num_edges(g1) == num_edges(g2));
    typename subgraph_t::edge_iterator e1_i, e1_i_end, e2_i, e2_i_end;
    boost::tie(e1_i, e1_i_end) = edges(g1);
    boost::tie(e2_i, e2_i_end) = edges(g2);
    for (; e1_i != e1_i_end; ++e1_i, ++e2_i)
    {
        BOOST_TEST(get(boost::edge_index, g1, *e1_i)
            == get(boost::edge_index, g2, *e2_i));
    }
    typename subgraph_t::const_children_iterator g1_i, g1_i_end, g2_i, g2_i_end;
    boost::tie(g1_i, g1_i_end) = g1.children();
    boost::tie(g2_i, g2_i_end) = g2.children();
    for (; g1_i != g1_i_end && g2_i != g2_i_end; ++g1_i, ++g2_i)
    {
        sub_cmp(*g1_i, *g2_i);
    }
    BOOST_TEST(g1_i == g1_i_end && g2_i == g2_i_end);
}

int main(int, char*[])
{
    using namespace boost;
    typedef adjacency_list< vecS, vecS, bidirectionalS,
        property< vertex_color_t, int >,
        property< edge_index_t, std::size_t, property< edge_weight_t, int > > >
        graph_t;
    typedef subgraph< graph_t > subgraph_t;
    typedef graph_traits< subgraph_t >::vertex_descriptor vertex_t;

    mt19937 gen;
    for (int t = 0; t < 100; t += 5)
    {
        subgraph_t g;
        int N = t + 2;
        std::vector< vertex_t > vertex_set;
        std::vector< std::pair< vertex_t, vertex_t > > edge_set;
        generate_random_graph(g, N, N * 2, gen, std::back_inserter(vertex_set),
            std::back_inserter(edge_set));

        graph_test< subgraph_t > gt;

        gt.test_incidence_graph(vertex_set, edge_set, g);
        gt.test_bidirectional_graph(vertex_set, edge_set, g);
        gt.test_adjacency_graph(vertex_set, edge_set, g);
        gt.test_vertex_list_graph(vertex_set, g);
        gt.test_edge_list_graph(vertex_set, edge_set, g);
        gt.test_adjacency_matrix(vertex_set, edge_set, g);

        std::vector< vertex_t > sub_vertex_set;
        std::vector< vertex_t > sub_global_map;
        std::vector< vertex_t > global_sub_map(num_vertices(g));
        std::vector< std::pair< vertex_t, vertex_t > > sub_edge_set;

        subgraph_t& g_s = g.create_subgraph();

        const std::set< vertex_t >::size_type Nsub = N / 2;

        // Collect a set of random vertices to put in the subgraph
        std::set< vertex_t > verts;
        while (verts.size() < Nsub)
            verts.insert(random_vertex(g, gen));

        for (std::set< vertex_t >::iterator it = verts.begin();
             it != verts.end(); ++it)
        {
            vertex_t v_global = *it;
            vertex_t v = add_vertex(v_global, g_s);
            sub_vertex_set.push_back(v);
            sub_global_map.push_back(v_global);
            global_sub_map[v_global] = v;
        }

        // compute induced edges
        BGL_FORALL_EDGES(e, g, subgraph_t)
        if (container_contains(sub_global_map, source(e, g))
            && container_contains(sub_global_map, target(e, g)))
            sub_edge_set.push_back(std::make_pair(
                global_sub_map[source(e, g)], global_sub_map[target(e, g)]));

        gt.test_incidence_graph(sub_vertex_set, sub_edge_set, g_s);
        gt.test_bidirectional_graph(sub_vertex_set, sub_edge_set, g_s);
        gt.test_adjacency_graph(sub_vertex_set, sub_edge_set, g_s);
        gt.test_vertex_list_graph(sub_vertex_set, g_s);
        gt.test_edge_list_graph(sub_vertex_set, sub_edge_set, g_s);
        gt.test_adjacency_matrix(sub_vertex_set, sub_edge_set, g_s);

        if (num_vertices(g_s) == 0)
            return 0;
        std::vector< int > weights;
        for (unsigned i = 0; i < num_vertices(g_s); ++i)
            weights.push_back(i * 2);
        gt.test_vertex_property_graph(weights, vertex_color_t(), g_s);

        // A regression test: the copy constructor of subgraph did not
        // copy one of the members, so local_edge->global_edge mapping
        // was broken.
        {
            subgraph_t g;
            graph_t::vertex_descriptor v1, v2;
            v1 = add_vertex(g);
            v2 = add_vertex(g);
            add_edge(v1, v2, g);

            subgraph_t sub
                = g.create_subgraph(vertices(g).first, vertices(g).second);

            graph_t::edge_iterator ei, ee;
            for (boost::tie(ei, ee) = edges(sub); ei != ee; ++ei)
            {
                // This used to segfault.
                get(edge_weight, sub, *ei);
            }
        }

        // This block generates a complete graph with 8 vertices,
        // and puts the first and last four of the vertices into two children.
        // Do these again to the children, so there are 4 grandchildren with 2
        // vertices for each. Use the copy constructor to generate a copy and
        // compare with the original one.
        {
            subgraph_t g1;

            for (size_t i = 0; i < 8; i++)
            {
                add_vertex(g1);
            }
            subgraph_t::vertex_iterator vi_start, vi, vi_end, vj_start, vj,
                vj_end;
            for (tie(vi, vi_end) = vertices(g1); vi != vi_end; ++vi)
            {
                for (tie(vj, vj_end) = vertices(g1); vj != vj_end; ++vj)
                {
                    if (*vi != *vj)
                    {
                        add_edge(*vi, *vj, g1);
                    }
                }
            }
            tie(vi_start, vi_end) = vertices(g1);
            vi = vi_start;
            for (size_t i = 0; i < 4; i++)
            {
                ++vi;
            }
            g1.create_subgraph(vi_start, vi);
            g1.create_subgraph(++vi, vi_end);
            subgraph_t::children_iterator gi1, gi2;
            gi2 = g1.children().first;
            gi1 = gi2++;
            tie(vi_start, vi_end) = vertices(*gi1);
            vi = vi_start;
            tie(vj_start, vj_end) = vertices(*gi2);
            vj = vj_start;
            for (size_t i = 0; i < 2; i++)
            {
                ++vi;
                ++vj;
            }
            (*gi1).create_subgraph(vi_start, vi);
            (*gi1).create_subgraph(++vi, vi_end);
            (*gi2).create_subgraph(vj_start, vj);
            (*gi2).create_subgraph(++vj, vj_end);
            subgraph_t g2(g1);
            sub_cmp(g1, g2);
        }

        // Bootstrap the test_graph framework.
        // TODO: Subgraph is fundamentally broken for property types.
        // TODO: Under construction.
        {
            using namespace boost;
            typedef property< edge_index_t, size_t, EdgeBundle > EdgeProp;
            typedef adjacency_list< vecS, vecS, directedS, VertexBundle,
                EdgeProp >
                BaseGraph;
            typedef subgraph< BaseGraph > Graph;
            typedef graph_traits< Graph >::vertex_descriptor Vertex;
            Graph g;
            Vertex v = add_vertex(g);

            typedef property_map< Graph, int VertexBundle::* >::type BundleMap;
            BundleMap map = get(&VertexBundle::value, g);
            get(map, v);
            //         put(map, v, 5);
            //         BOOST_ASSERT(get(map, v) == 5);

            //         test_graph(g);
            return boost::report_errors();
        }
    }
    return boost::report_errors();
}