//

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

// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.

// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek

//

// 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_UTILITY_HPP

#define BOOST_GRAPH_UTILITY_HPP



#include <stdlib.h>

#include <iostream>

#include <algorithm>

#include <assert.h>

#include <boost/config.hpp>

#include <boost/tuple/tuple.hpp>



#if !defined BOOST_NO_SLIST

#  ifdef BOOST_SLIST_HEADER

#    include BOOST_SLIST_HEADER

#  else

#    include <slist>

#  endif

#endif



#include <boost/graph/graph_traits.hpp>

#include <boost/graph/properties.hpp>

#include <boost/pending/container_traits.hpp>

#include <boost/graph/depth_first_search.hpp>

// iota moved to detail/algorithm.hpp

#include <boost/detail/algorithm.hpp>



namespace boost {



  // Provide an undirected graph interface alternative to the

  // the source() and target() edge functions.

  template <class UndirectedGraph>

  inline 

  std::pair<typename graph_traits<UndirectedGraph>::vertex_descriptor,

            typename graph_traits<UndirectedGraph>::vertex_descriptor>

  incident(typename graph_traits<UndirectedGraph>::edge_descriptor e,

           UndirectedGraph& g)

  {

    return std::make_pair(source(e,g), target(e,g));

  }



  // Provide an undirected graph interface alternative

  // to the out_edges() function.

  template <class Graph>

  inline 

  std::pair<typename graph_traits<Graph>::out_edge_iterator,

            typename graph_traits<Graph>::out_edge_iterator>

  incident_edges(typename graph_traits<Graph>::vertex_descriptor u,

                 Graph& g)

  {

    return out_edges(u, g);

  }



  template <class Graph>

  inline typename graph_traits<Graph>::vertex_descriptor

  opposite(typename graph_traits<Graph>::edge_descriptor e,

           typename graph_traits<Graph>::vertex_descriptor v,

           const Graph& g)

  {

    typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor;

    if (v == source(e, g))

      return target(e, g);

    else if (v == target(e, g))

      return source(e, g);

    else

      return vertex_descriptor();

  }



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

  // Some handy predicates



  template <typename Vertex, typename Graph>

  struct incident_from_predicate {

    incident_from_predicate(Vertex u, const Graph& g)

      : m_u(u), m_g(g) { }

    template <class Edge>

    bool operator()(const Edge& e) const {

      return source(e, m_g) == m_u;

    }

    Vertex m_u;

    const Graph& m_g;

  };

  template <typename Vertex, typename Graph>

  inline incident_from_predicate<Vertex, Graph>

  incident_from(Vertex u, const Graph& g) {

    return incident_from_predicate<Vertex, Graph>(u, g);

  }

  

  template <typename Vertex, typename Graph>

  struct incident_to_predicate {

    incident_to_predicate(Vertex u, const Graph& g)

      : m_u(u), m_g(g) { }

    template <class Edge>

    bool operator()(const Edge& e) const {

      return target(e, m_g) == m_u;

    }

    Vertex m_u;

    const Graph& m_g;

  };

  template <typename Vertex, typename Graph>

  inline incident_to_predicate<Vertex, Graph>

  incident_to(Vertex u, const Graph& g) {

    return incident_to_predicate<Vertex, Graph>(u, g);

  }



  template <typename Vertex, typename Graph>

  struct incident_on_predicate {

    incident_on_predicate(Vertex u, const Graph& g)

      : m_u(u), m_g(g) { }

    template <class Edge>

    bool operator()(const Edge& e) const {

      return source(e, m_g) == m_u || target(e, m_g) == m_u;

    }

    Vertex m_u;

    const Graph& m_g;

  };

  template <typename Vertex, typename Graph>

  inline incident_on_predicate<Vertex, Graph>

  incident_on(Vertex u, const Graph& g) {

    return incident_on_predicate<Vertex, Graph>(u, g);

  }

  

  template <typename Vertex, typename Graph>

  struct connects_predicate {

    connects_predicate(Vertex u, Vertex v, const Graph& g)

      : m_u(u), m_v(v), m_g(g) { }

    template <class Edge>

    bool operator()(const Edge& e) const {

      if (is_directed(m_g))

        return source(e, m_g) == m_u && target(e, m_g) == m_v;

      else

        return (source(e, m_g) == m_u && target(e, m_g) == m_v)

          || (source(e, m_g) == m_v && target(e, m_g) == m_u);

    }

    Vertex m_u, m_v;

    const Graph& m_g;

  };

  template <typename Vertex, typename Graph>

  inline connects_predicate<Vertex, Graph>

  connects(Vertex u, Vertex v, const Graph& g) {

          return connects_predicate<Vertex, Graph>(u, v, g);

  }





  // Need to convert all of these printing functions to take an ostream object

  // -JGS



  template <class IncidenceGraph, class Name>

  void print_in_edges(const IncidenceGraph& G, Name name)

  {

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

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

      std::cout << get(name,*ui) << " <-- ";

      typename graph_traits<IncidenceGraph>

        ::in_edge_iterator ei, ei_end;

      for(tie(ei,ei_end) = in_edges(*ui,G); ei != ei_end; ++ei)

        std::cout << get(name,source(*ei,G)) << " ";

      std::cout << std::endl;

    }

  }



  template <class IncidenceGraph, class Name>

  void print_graph_dispatch(const IncidenceGraph& G, Name name, directed_tag)

  {

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

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

      std::cout << get(name,*ui) << " --> ";

      typename graph_traits<IncidenceGraph>

        ::out_edge_iterator ei, ei_end;

      for(tie(ei,ei_end) = out_edges(*ui,G); ei != ei_end; ++ei)

        std::cout << get(name,target(*ei,G)) << " ";

      std::cout << std::endl;

    }

  }

  template <class IncidenceGraph, class Name>

  void print_graph_dispatch(const IncidenceGraph& G, Name name, undirected_tag)

  {

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

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

      std::cout << get(name,*ui) << " <--> ";

      typename graph_traits<IncidenceGraph>

        ::out_edge_iterator ei, ei_end;

      for(tie(ei,ei_end) = out_edges(*ui,G); ei != ei_end; ++ei)

        std::cout << get(name,target(*ei,G)) << " ";

      std::cout << std::endl;

    }

  }

  template <class IncidenceGraph, class Name>

  void print_graph(const IncidenceGraph& G, Name name)

  {

    typedef typename graph_traits<IncidenceGraph>

      ::directed_category Cat;

    print_graph_dispatch(G, name, Cat());

  }

  template <class IncidenceGraph>

  void print_graph(const IncidenceGraph& G) {

    print_graph(G, get(vertex_index, G));

  }



  template <class EdgeListGraph, class Name>

  void print_edges(const EdgeListGraph& G, Name name)

  {

    typename graph_traits<EdgeListGraph>::edge_iterator ei, ei_end;

    for (tie(ei, ei_end) = edges(G); ei != ei_end; ++ei)

      std::cout << "(" << get(name, source(*ei, G))

                << "," << get(name, target(*ei, G)) << ") ";

    std::cout << std::endl;

  }



  template <class EdgeListGraph, class VertexName, class EdgeName>

  void print_edges2(const EdgeListGraph& G, VertexName vname, EdgeName ename)

  {

    typename graph_traits<EdgeListGraph>::edge_iterator ei, ei_end;

    for (tie(ei, ei_end) = edges(G); ei != ei_end; ++ei)

      std::cout << get(ename, *ei) << "(" << get(vname, source(*ei, G))

                << "," << get(vname, target(*ei, G)) << ") ";

    std::cout << std::endl;

  }



  template <class VertexListGraph, class Name>

  void print_vertices(const VertexListGraph& G, Name name)

  {

    typename graph_traits<VertexListGraph>::vertex_iterator vi,vi_end;

    for (tie(vi,vi_end) = vertices(G); vi != vi_end; ++vi)

      std::cout << get(name,*vi) << " ";

    std::cout << std::endl;

  }



  template <class Graph, class Vertex>

  bool is_adj_dispatch(Graph& g, Vertex a, Vertex b, bidirectional_tag)

  {

    typedef typename graph_traits<Graph>::edge_descriptor 

      edge_descriptor;

    typename graph_traits<Graph>::adjacency_iterator vi, viend, 

      adj_found;

    tie(vi, viend) = adjacent_vertices(a, g);

    adj_found = std::find(vi, viend, b);

    if (adj_found == viend)

      return false;  



    typename graph_traits<Graph>::out_edge_iterator oi, oiend, 

      out_found;

    tie(oi, oiend) = out_edges(a, g);

    out_found = std::find_if(oi, oiend, incident_to(b, g));

    if (out_found == oiend)

      return false;



    typename graph_traits<Graph>::in_edge_iterator ii, iiend, 

      in_found;

    tie(ii, iiend) = in_edges(b, g);

    in_found = std::find_if(ii, iiend, incident_from(a, g));

    if (in_found == iiend)

      return false;



    return true;

  }

  template <class Graph, class Vertex>

  bool is_adj_dispatch(Graph& g, Vertex a, Vertex b, directed_tag)

  {

    typedef typename graph_traits<Graph>::edge_descriptor 

      edge_descriptor;

    typename graph_traits<Graph>::adjacency_iterator vi, viend, found;

    tie(vi, viend) = adjacent_vertices(a, g);

#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 && defined(__SGI_STL_PORT)

    // Getting internal compiler error with std::find()

    found = viend;

    for (; vi != viend; ++vi)

      if (*vi == b) {

        found = vi;

        break;

      }

#else

    found = std::find(vi, viend, b);

#endif

    if ( found == viend )

      return false;



    typename graph_traits<Graph>::out_edge_iterator oi, oiend, 

      out_found;

    tie(oi, oiend) = out_edges(a, g);



#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 && defined(__SGI_STL_PORT)

    // Getting internal compiler error with std::find()

    out_found = oiend;

    for (; oi != oiend; ++oi)

      if (target(*oi, g) == b) {

        out_found = oi;

        break;

      }

#else

    out_found = std::find_if(oi, oiend, incident_to(b, g));

#endif

    if (out_found == oiend)

      return false;

    return true;

  }

  template <class Graph, class Vertex>

  bool is_adj_dispatch(Graph& g, Vertex a, Vertex b, undirected_tag)

  {

    return is_adj_dispatch(g, a, b, directed_tag());

  }



  template <class Graph, class Vertex>

  bool is_adjacent(Graph& g, Vertex a, Vertex b) {

    typedef typename graph_traits<Graph>::directed_category Cat;

    return is_adj_dispatch(g, a, b, Cat());

  }



  template <class Graph, class Edge>

  bool in_edge_set(Graph& g, Edge e)

  {

    typename Graph::edge_iterator ei, ei_end, found;

    tie(ei, ei_end) = edges(g);

    found = std::find(ei, ei_end, e);

    return found != ei_end;

  }



  template <class Graph, class Vertex>

  bool in_vertex_set(Graph& g, Vertex v)

  {

    typename Graph::vertex_iterator vi, vi_end, found;

    tie(vi, vi_end) = vertices(g);

    found = std::find(vi, vi_end, v);

    return found != vi_end;

  }



  template <class Graph, class Vertex>

  bool in_edge_set(Graph& g, Vertex u, Vertex v)

  {

    typename Graph::edge_iterator ei, ei_end;

    for (tie(ei,ei_end) = edges(g); ei != ei_end; ++ei)

      if (source(*ei,g) == u && target(*ei,g) == v)

        return true;

    return false;

  }



  // is x a descendant of y?

  template <typename ParentMap>

  inline bool is_descendant

  (typename property_traits<ParentMap>::value_type x,

   typename property_traits<ParentMap>::value_type y,

   ParentMap parent) 

  {

    if (get(parent, x) == x) // x is the root of the tree

      return false;

    else if (get(parent, x) == y)

      return true;

    else

      return is_descendant(get(parent, x), y, parent);

  }



  // is y reachable from x?

  template <typename IncidenceGraph, typename VertexColorMap>

  inline bool is_reachable

    (typename graph_traits<IncidenceGraph>::vertex_descriptor x,

     typename graph_traits<IncidenceGraph>::vertex_descriptor y,

     const IncidenceGraph& g,

     VertexColorMap color) // should start out white for every vertex

  {

    typedef typename property_traits<VertexColorMap>::value_type ColorValue;

    dfs_visitor<> vis;

    depth_first_visit(g, x, vis, color);

    return get(color, y) != color_traits<ColorValue>::white();

  }



  // Is the undirected graph connected?

  // Is the directed graph strongly connected?

  template <typename VertexListGraph, typename VertexColorMap>

  inline bool is_connected(const VertexListGraph& g, VertexColorMap color)

  {

    typedef typename property_traits<VertexColorMap>::value_type ColorValue;

    typedef color_traits<ColorValue> Color;

    typename graph_traits<VertexListGraph>::vertex_iterator 

      ui, ui_end, vi, vi_end, ci, ci_end;

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

      for (tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)

        if (*ui != *vi) {

          for (tie(ci, ci_end) = vertices(g); ci != ci_end; ++ci) 

            put(color, *ci, Color::white());

          if (! is_reachable(*ui, *vi, color))

            return false;

        }

    return true;

  }



  template <typename Graph>

  bool is_self_loop

    (typename graph_traits<Graph>::edge_descriptor e,

     const Graph& g)

  {

    return source(e, g) == target(e, g);

  }





  template <class T1, class T2>

  std::pair<T1,T2> 

  make_list(const T1& t1, const T2& t2) 

    { return std::make_pair(t1, t2); }



  template <class T1, class T2, class T3>

  std::pair<T1,std::pair<T2,T3> > 

  make_list(const T1& t1, const T2& t2, const T3& t3)

    { return std::make_pair(t1, std::make_pair(t2, t3)); }



  template <class T1, class T2, class T3, class T4>

  std::pair<T1,std::pair<T2,std::pair<T3,T4> > > 

  make_list(const T1& t1, const T2& t2, const T3& t3, const T4& t4)

    { return std::make_pair(t1, std::make_pair(t2, std::make_pair(t3, t4))); }



  template <class T1, class T2, class T3, class T4, class T5>

  std::pair<T1,std::pair<T2,std::pair<T3,std::pair<T4,T5> > > > 

  make_list(const T1& t1, const T2& t2, const T3& t3, const T4& t4, const T5& t5)

    { return std::make_pair(t1, std::make_pair(t2, std::make_pair(t3, std::make_pair(t4, t5)))); }



} /* namespace boost */



#endif /* BOOST_GRAPH_UTILITY_HPP*/

