//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
// Copyright 2009 Trustees of Indiana University.
// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek, Michael Hansen
//
// 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 <vector>

#include <boost/foreach.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/incremental_components.hpp>
#include <boost/pending/disjoint_sets.hpp>

using namespace boost;

int main(int argc, char* argv[])
{
    typedef adjacency_list< vecS, vecS, undirectedS > Graph;
    typedef graph_traits< Graph >::vertex_descriptor Vertex;
    // typedef graph_traits<Graph>::edge_descriptor Edge;
    typedef graph_traits< Graph >::vertices_size_type VertexIndex;

    // Create a graph
    const int VERTEX_COUNT = 6;
    Graph graph(VERTEX_COUNT);

    add_edge(0, 1, graph);
    add_edge(1, 4, graph);

    // reate the disjoint-sets object, which requires rank and parent
    // vertex properties.
    std::vector< Vertex > rank(num_vertices(graph));
    std::vector< Vertex > parent(num_vertices(graph));

    typedef VertexIndex* Rank;
    typedef Vertex* Parent;
    disjoint_sets< Rank, Parent > ds(&rank[0], &parent[0]);

    // Determine the connected components, storing the results in the
    // disjoint-sets object.
    initialize_incremental_components(graph, ds);
    incremental_components(graph, ds);

    // Add a couple more edges and update the disjoint-sets
    add_edge(4, 0, graph);
    add_edge(2, 5, graph);

    ds.union_set(4, 0);
    ds.union_set(2, 5);

    BOOST_FOREACH (Vertex current_vertex, vertices(graph))
    {
        std::cout << "representative[" << current_vertex
                  << "] = " << ds.find_set(current_vertex) << std::endl;
    }

    std::cout << std::endl;

    // Generate component index. NOTE: We would need to pass in a vertex
    // index map into the component_index constructor if our graph type
    // used listS instead of vecS (identity_property_map is used by
    // default).
    typedef component_index< VertexIndex > Components;
    Components components(parent.begin(), parent.end());

    // Iterate through the component indices
    BOOST_FOREACH (VertexIndex component_index, components)
    {
        std::cout << "component " << component_index << " contains: ";

        // Iterate through the child vertex indices for [component_index]
        BOOST_FOREACH (VertexIndex child_index, components[component_index])
        {
            std::cout << child_index << " ";
        }

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

    return (0);
}