//

//=======================================================================

// Copyright 2002 Marc Wintermantel (wintermantel@even-ag.ch)

// ETH Zurich, Center of Structure Technologies (www.imes.ethz.ch/st)

//

// 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_WAVEFRONT_HPP

#define BOOST_GRAPH_WAVEFRONT_HPP

#include <boost/config.hpp>

#include <boost/graph/graph_traits.hpp>

#include <boost/detail/numeric_traits.hpp>

#include <boost/graph/bandwidth.hpp>

#include <cmath>

#include <vector>

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

namespace boost {

  template <typename Graph, typename VertexIndexMap>

  typename graph_traits<Graph>::vertices_size_type

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

                const Graph& g,

                VertexIndexMap index)

  {

    typename graph_traits<Graph>::vertex_descriptor v, w;

    typename graph_traits<Graph>::vertices_size_type b = 1;

    typename graph_traits<Graph>::out_edge_iterator edge_it2, edge_it2_end; 

    typename graph_traits<Graph>::vertices_size_type index_i = index[i];

    std::vector<bool> rows_active(num_vertices(g), false);

    rows_active[index_i] = true;

      typename graph_traits<Graph>::vertex_iterator ui, ui_end;

      for (tie(ui, ui_end) = vertices(g); ui != ui_end; ++ui)

      {

        v = *ui;

          if(index[v] <= index_i)

            {

              for (tie(edge_it2, edge_it2_end) = out_edges(v, g); edge_it2 != edge_it2_end; ++edge_it2)

              {

                w = target(*edge_it2, g);

                if( (index[w] >= index_i) && (!rows_active[index[w]]) )

                  {

                    b++;

                    rows_active[index[w]] = true;

                  }

              }

            }

      }

    return b;

  }

  template <typename Graph>

  typename graph_traits<Graph>::vertices_size_type

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

                const Graph& g)

  {

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

  }

  template <typename Graph, typename VertexIndexMap>

  typename graph_traits<Graph>::vertices_size_type

  max_wavefront(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_wavefront(*i, g, index));

    return b;

  }

  template <typename Graph>

  typename graph_traits<Graph>::vertices_size_type

  max_wavefront(const Graph& g)

  {

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

  }

  template <typename Graph, typename VertexIndexMap>

  double

  aver_wavefront(const Graph& g, VertexIndexMap index)

  {

    double b = 0;

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

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

      b += ith_wavefront(*i, g, index);

    b /= num_vertices(g);

    return b;

  }

  template <typename Graph>

  double

  aver_wavefront(const Graph& g)

  {

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

  }

  template <typename Graph, typename VertexIndexMap>

  double

  rms_wavefront(const Graph& g, VertexIndexMap index)

  {

    double b = 0;

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

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

      b += std::pow(double ( ith_wavefront(*i, g, index) ), 2.0);

    b /= num_vertices(g);

    return std::sqrt(b);

  }

  template <typename Graph>

  double

  rms_wavefront(const Graph& g)

  {

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

  }

} // namespace boost

#endif // BOOST_GRAPH_WAVEFRONT_HPP