// Copyright (c) Jeremy Siek 2001, Marc Wintermantel 2002

//

// 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)

#ifndef BOOST_GRAPH_BANDWIDTH_HPP

#define BOOST_GRAPH_BANDWIDTH_HPP

#include <algorithm> // for std::min and std::max

#include <boost/config.hpp>

#include <boost/graph/graph_traits.hpp>

#include <boost/detail/numeric_traits.hpp>

namespace boost {

  template <typename Graph, typename VertexIndexMap>

  typename graph_traits<Graph>::vertices_size_type

  ith_bandwidth(typename graph_traits<Graph>::vertex_descriptor i,

                const Graph& g,

                VertexIndexMap index)

  {

    BOOST_USING_STD_MAX();

    typedef typename graph_traits<Graph>::vertices_size_type size_type;

    size_type b = 0;

    typename graph_traits<Graph>::out_edge_iterator e, end;

    for (tie(e, end) = out_edges(i, g); e != end; ++e) {

      int f_i = get(index, i);

      int f_j = get(index, target(*e, g));

      using namespace std; // to call abs() unqualified

      if(f_i > f_j)

          b = max BOOST_PREVENT_MACRO_SUBSTITUTION (b, size_type(f_i - f_j));

    }

    return b;

  }

  template <typename Graph>

  typename graph_traits<Graph>::vertices_size_type

  ith_bandwidth(typename graph_traits<Graph>::vertex_descriptor i,

                const Graph& g)

  {

    return ith_bandwidth(i, g, get(vertex_index, g));

  }

  template <typename Graph, typename VertexIndexMap>

  typename graph_traits<Graph>::vertices_size_type

  bandwidth(const Graph& g, VertexIndexMap index)

  {

    BOOST_USING_STD_MAX();

    typename graph_traits<Graph>::vertices_size_type b = 0;

    typename graph_traits<Graph>::vertex_iterator i, end;

    for (tie(i, end) = vertices(g); i != end; ++i)

        b = max BOOST_PREVENT_MACRO_SUBSTITUTION (b, ith_bandwidth(*i, g, index));

    return b;

  }

  template <typename Graph>

  typename graph_traits<Graph>::vertices_size_type

  bandwidth(const Graph& g)

  {

    return bandwidth(g, get(vertex_index, g));

  }

  template <typename Graph, typename VertexIndexMap>

  typename graph_traits<Graph>::vertices_size_type

  edgesum(const Graph& g, VertexIndexMap index_map)

  {

    typedef typename graph_traits<Graph>::vertices_size_type size_type;

    typedef typename detail::numeric_traits<size_type>::difference_type diff_t;

    size_type sum = 0;

    typename graph_traits<Graph>::edge_iterator i, end;

    for (tie(i, end) = edges(g); i != end; ++i) {

      diff_t f_u = get(index_map, source(*i, g));

      diff_t f_v = get(index_map, target(*i, g));

      using namespace std; // to call abs() unqualified

      sum += abs(f_u - f_v);

    }

    return sum;

  }

} // namespace boost

#endif // BOOST_GRAPH_BANDWIDTH_HPP