Edit: /usr/include/boost/graph/neighbor_bfs.hpp (11763B)
//
//=======================================================================
// 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_NEIGHBOR_BREADTH_FIRST_SEARCH_HPP
#define BOOST_GRAPH_NEIGHBOR_BREADTH_FIRST_SEARCH_HPP
/*
Neighbor Breadth First Search
Like BFS, but traverses in-edges as well as out-edges.
(for directed graphs only. use normal BFS for undirected graphs)
*/
#include
#include
#include
#include
#include
#include
#include
#include
#include
namespace boost
{
template < class Visitor, class Graph > struct NeighborBFSVisitorConcept
{
void constraints()
{
BOOST_CONCEPT_ASSERT((CopyConstructibleConcept< Visitor >));
vis.initialize_vertex(u, g);
vis.discover_vertex(u, g);
vis.examine_vertex(u, g);
vis.examine_out_edge(e, g);
vis.examine_in_edge(e, g);
vis.tree_out_edge(e, g);
vis.tree_in_edge(e, g);
vis.non_tree_out_edge(e, g);
vis.non_tree_in_edge(e, g);
vis.gray_target(e, g);
vis.black_target(e, g);
vis.gray_source(e, g);
vis.black_source(e, g);
vis.finish_vertex(u, g);
}
Visitor vis;
Graph g;
typename graph_traits< Graph >::vertex_descriptor u;
typename graph_traits< Graph >::edge_descriptor e;
};
template < class Visitors = null_visitor > class neighbor_bfs_visitor
{
public:
neighbor_bfs_visitor(Visitors vis = Visitors()) : m_vis(vis) {}
template < class Vertex, class Graph >
void initialize_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, on_initialize_vertex());
}
template < class Vertex, class Graph >
void discover_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, on_discover_vertex());
}
template < class Vertex, class Graph >
void examine_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, on_examine_vertex());
}
template < class Edge, class Graph > void examine_out_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_examine_edge());
}
template < class Edge, class Graph > void tree_out_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_tree_edge());
}
template < class Edge, class Graph >
void non_tree_out_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_non_tree_edge());
}
template < class Edge, class Graph > void gray_target(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_gray_target());
}
template < class Edge, class Graph > void black_target(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_black_target());
}
template < class Edge, class Graph > void examine_in_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_examine_edge());
}
template < class Edge, class Graph > void tree_in_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_tree_edge());
}
template < class Edge, class Graph > void non_tree_in_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_non_tree_edge());
}
template < class Edge, class Graph > void gray_source(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_gray_target());
}
template < class Edge, class Graph > void black_source(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, on_black_target());
}
template < class Vertex, class Graph >
void finish_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, on_finish_vertex());
}
protected:
Visitors m_vis;
};
template < class Visitors >
neighbor_bfs_visitor< Visitors > make_neighbor_bfs_visitor(Visitors vis)
{
return neighbor_bfs_visitor< Visitors >(vis);
}
namespace detail
{
template < class BidirectionalGraph, class Buffer, class BFSVisitor,
class ColorMap >
void neighbor_bfs_impl(const BidirectionalGraph& g,
typename graph_traits< BidirectionalGraph >::vertex_descriptor s,
Buffer& Q, BFSVisitor vis, ColorMap color)
{
BOOST_CONCEPT_ASSERT((BidirectionalGraphConcept< BidirectionalGraph >));
typedef graph_traits< BidirectionalGraph > GTraits;
typedef typename GTraits::vertex_descriptor Vertex;
typedef typename GTraits::edge_descriptor Edge;
BOOST_CONCEPT_ASSERT(
(NeighborBFSVisitorConcept< BFSVisitor, BidirectionalGraph >));
BOOST_CONCEPT_ASSERT((ReadWritePropertyMapConcept< ColorMap, Vertex >));
typedef typename property_traits< ColorMap >::value_type ColorValue;
typedef color_traits< ColorValue > Color;
put(color, s, Color::gray());
vis.discover_vertex(s, g);
Q.push(s);
while (!Q.empty())
{
Vertex u = Q.top();
Q.pop(); // pop before push to avoid problem if Q is priority_queue.
vis.examine_vertex(u, g);
typename GTraits::out_edge_iterator ei, ei_end;
for (boost::tie(ei, ei_end) = out_edges(u, g); ei != ei_end; ++ei)
{
Edge e = *ei;
vis.examine_out_edge(e, g);
Vertex v = target(e, g);
ColorValue v_color = get(color, v);
if (v_color == Color::white())
{
vis.tree_out_edge(e, g);
put(color, v, Color::gray());
vis.discover_vertex(v, g);
Q.push(v);
}
else
{
vis.non_tree_out_edge(e, g);
if (v_color == Color::gray())
vis.gray_target(e, g);
else
vis.black_target(e, g);
}
} // for out-edges
typename GTraits::in_edge_iterator in_ei, in_ei_end;
for (boost::tie(in_ei, in_ei_end) = in_edges(u, g);
in_ei != in_ei_end; ++in_ei)
{
Edge e = *in_ei;
vis.examine_in_edge(e, g);
Vertex v = source(e, g);
ColorValue v_color = get(color, v);
if (v_color == Color::white())
{
vis.tree_in_edge(e, g);
put(color, v, Color::gray());
vis.discover_vertex(v, g);
Q.push(v);
}
else
{
vis.non_tree_in_edge(e, g);
if (v_color == Color::gray())
vis.gray_source(e, g);
else
vis.black_source(e, g);
}
} // for in-edges
put(color, u, Color::black());
vis.finish_vertex(u, g);
} // while
}
template < class VertexListGraph, class ColorMap, class BFSVisitor, class P,
class T, class R >
void neighbor_bfs_helper(VertexListGraph& g,
typename graph_traits< VertexListGraph >::vertex_descriptor s,
ColorMap color, BFSVisitor vis,
const bgl_named_params< P, T, R >& params)
{
typedef graph_traits< VertexListGraph > Traits;
// Buffer default
typedef typename Traits::vertex_descriptor Vertex;
typedef boost::queue< Vertex > queue_t;
queue_t Q;
// Initialization
typedef typename property_traits< ColorMap >::value_type ColorValue;
typedef color_traits< ColorValue > Color;
typename boost::graph_traits< VertexListGraph >::vertex_iterator i,
i_end;
for (boost::tie(i, i_end) = vertices(g); i != i_end; ++i)
{
put(color, *i, Color::white());
vis.initialize_vertex(*i, g);
}
neighbor_bfs_impl(g, s,
choose_param(get_param(params, buffer_param_t()), boost::ref(Q))
.get(),
vis, color);
}
//-------------------------------------------------------------------------
// Choose between default color and color parameters. Using
// function dispatching so that we don't require vertex index if
// the color default is not being used.
template < class ColorMap > struct neighbor_bfs_dispatch
{
template < class VertexListGraph, class P, class T, class R >
static void apply(VertexListGraph& g,
typename graph_traits< VertexListGraph >::vertex_descriptor s,
const bgl_named_params< P, T, R >& params, ColorMap color)
{
neighbor_bfs_helper(g, s, color,
choose_param(get_param(params, graph_visitor),
make_neighbor_bfs_visitor(null_visitor())),
params);
}
};
template <> struct neighbor_bfs_dispatch< param_not_found >
{
template < class VertexListGraph, class P, class T, class R >
static void apply(VertexListGraph& g,
typename graph_traits< VertexListGraph >::vertex_descriptor s,
const bgl_named_params< P, T, R >& params, param_not_found)
{
std::vector< default_color_type > color_vec(num_vertices(g));
null_visitor null_vis;
neighbor_bfs_helper(g, s,
make_iterator_property_map(color_vec.begin(),
choose_const_pmap(
get_param(params, vertex_index), g, vertex_index),
color_vec[0]),
choose_param(get_param(params, graph_visitor),
make_neighbor_bfs_visitor(null_vis)),
params);
}
};
} // namespace detail
// Named Parameter Variant
template < class VertexListGraph, class P, class T, class R >
void neighbor_breadth_first_search(const VertexListGraph& g,
typename graph_traits< VertexListGraph >::vertex_descriptor s,
const bgl_named_params< P, T, R >& params)
{
// The graph is passed by *const* reference so that graph adaptors
// (temporaries) can be passed into this function. However, the
// graph is not really const since we may write to property maps
// of the graph.
VertexListGraph& ng = const_cast< VertexListGraph& >(g);
typedef typename get_param_type< vertex_color_t,
bgl_named_params< P, T, R > >::type C;
detail::neighbor_bfs_dispatch< C >::apply(
ng, s, params, get_param(params, vertex_color));
}
// This version does not initialize colors, user has to.
template < class IncidenceGraph, class P, class T, class R >
void neighbor_breadth_first_visit(IncidenceGraph& g,
typename graph_traits< IncidenceGraph >::vertex_descriptor s,
const bgl_named_params< P, T, R >& params)
{
typedef graph_traits< IncidenceGraph > Traits;
// Buffer default
typedef boost::queue< typename Traits::vertex_descriptor > queue_t;
queue_t Q;
detail::neighbor_bfs_impl(g, s,
choose_param(get_param(params, buffer_param_t()), boost::ref(Q)).get(),
choose_param(get_param(params, graph_visitor),
make_neighbor_bfs_visitor(null_visitor())),
choose_pmap(get_param(params, vertex_color), g, vertex_color));
}
} // namespace boost
#endif // BOOST_GRAPH_NEIGHBOR_BREADTH_FIRST_SEARCH_HPP