//

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

 // 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