boost/graph/breadth_first_search.hpp
//
//=======================================================================
// 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_BREADTH_FIRST_SEARCH_HPP
#define BOOST_GRAPH_BREADTH_FIRST_SEARCH_HPP
/*
Breadth First Search Algorithm (Cormen, Leiserson, and Rivest p. 470)
*/
#include <boost/config.hpp>
#include <vector>
#include <boost/pending/queue.hpp>
#include <boost/graph/graph_traits.hpp>
#include <boost/graph/graph_concepts.hpp>
#include <boost/graph/visitors.hpp>
#include <boost/graph/named_function_params.hpp>
#include <boost/graph/overloading.hpp>
#include <boost/graph/graph_concepts.hpp>
#include <boost/graph/two_bit_color_map.hpp>
#include <boost/graph/detail/mpi_include.hpp>
#include <boost/concept/assert.hpp>
#include BOOST_GRAPH_MPI_INCLUDE(<boost/graph/distributed/concepts.hpp>)
namespace boost {
template <class Visitor, class Graph>
struct BFSVisitorConcept {
void constraints() {
BOOST_CONCEPT_ASSERT(( CopyConstructibleConcept<Visitor> ));
vis.initialize_vertex(u, g);
vis.discover_vertex(u, g);
vis.examine_vertex(u, g);
vis.examine_edge(e, g);
vis.tree_edge(e, g);
vis.non_tree_edge(e, g);
vis.gray_target(e, g);
vis.black_target(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;
};
// Multiple-source version
template <class IncidenceGraph, class Buffer, class BFSVisitor,
class ColorMap, class SourceIterator>
void breadth_first_visit
(const IncidenceGraph& g,
SourceIterator sources_begin, SourceIterator sources_end,
Buffer& Q, BFSVisitor vis, ColorMap color)
{
BOOST_CONCEPT_ASSERT(( IncidenceGraphConcept<IncidenceGraph> ));
typedef graph_traits<IncidenceGraph> GTraits;
typedef typename GTraits::vertex_descriptor Vertex;
BOOST_CONCEPT_ASSERT(( BFSVisitorConcept<BFSVisitor, IncidenceGraph> ));
BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<ColorMap, Vertex> ));
typedef typename property_traits<ColorMap>::value_type ColorValue;
typedef color_traits<ColorValue> Color;
typename GTraits::out_edge_iterator ei, ei_end;
for (; sources_begin != sources_end; ++sources_begin) {
Vertex s = *sources_begin;
put(color, s, Color::gray()); vis.discover_vertex(s, g);
Q.push(s);
}
while (! Q.empty()) {
Vertex u = Q.top(); Q.pop(); vis.examine_vertex(u, g);
for (boost::tie(ei, ei_end) = out_edges(u, g); ei != ei_end; ++ei) {
Vertex v = target(*ei, g); vis.examine_edge(*ei, g);
ColorValue v_color = get(color, v);
if (v_color == Color::white()) { vis.tree_edge(*ei, g);
put(color, v, Color::gray()); vis.discover_vertex(v, g);
Q.push(v);
} else { vis.non_tree_edge(*ei, g);
if (v_color == Color::gray()) vis.gray_target(*ei, g);
else vis.black_target(*ei, g);
}
} // end for
put(color, u, Color::black()); vis.finish_vertex(u, g);
} // end while
} // breadth_first_visit
// Single-source version
template <class IncidenceGraph, class Buffer, class BFSVisitor,
class ColorMap>
void breadth_first_visit
(const IncidenceGraph& g,
typename graph_traits<IncidenceGraph>::vertex_descriptor s,
Buffer& Q, BFSVisitor vis, ColorMap color)
{
typename graph_traits<IncidenceGraph>::vertex_descriptor sources[1] = {s};
breadth_first_visit(g, sources, sources + 1, Q, vis, color);
}
template <class VertexListGraph, class SourceIterator,
class Buffer, class BFSVisitor,
class ColorMap>
void breadth_first_search
(const VertexListGraph& g,
SourceIterator sources_begin, SourceIterator sources_end,
Buffer& Q, BFSVisitor vis, ColorMap color)
{
// 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) {
vis.initialize_vertex(*i, g);
put(color, *i, Color::white());
}
breadth_first_visit(g, sources_begin, sources_end, Q, vis, color);
}
template <class VertexListGraph, class Buffer, class BFSVisitor,
class ColorMap>
void breadth_first_search
(const VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
Buffer& Q, BFSVisitor vis, ColorMap color)
{
typename graph_traits<VertexListGraph>::vertex_descriptor sources[1] = {s};
breadth_first_search(g, sources, sources + 1, Q, vis, color);
}
namespace graph { struct bfs_visitor_event_not_overridden {}; }
template <class Visitors = null_visitor>
class bfs_visitor {
public:
bfs_visitor() { }
bfs_visitor(Visitors vis) : m_vis(vis) { }
template <class Vertex, class Graph>
graph::bfs_visitor_event_not_overridden
initialize_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, ::boost::on_initialize_vertex());
return graph::bfs_visitor_event_not_overridden();
}
template <class Vertex, class Graph>
graph::bfs_visitor_event_not_overridden
discover_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, ::boost::on_discover_vertex());
return graph::bfs_visitor_event_not_overridden();
}
template <class Vertex, class Graph>
graph::bfs_visitor_event_not_overridden
examine_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, ::boost::on_examine_vertex());
return graph::bfs_visitor_event_not_overridden();
}
template <class Edge, class Graph>
graph::bfs_visitor_event_not_overridden
examine_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, ::boost::on_examine_edge());
return graph::bfs_visitor_event_not_overridden();
}
template <class Edge, class Graph>
graph::bfs_visitor_event_not_overridden
tree_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, ::boost::on_tree_edge());
return graph::bfs_visitor_event_not_overridden();
}
template <class Edge, class Graph>
graph::bfs_visitor_event_not_overridden
non_tree_edge(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, ::boost::on_non_tree_edge());
return graph::bfs_visitor_event_not_overridden();
}
template <class Edge, class Graph>
graph::bfs_visitor_event_not_overridden
gray_target(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, ::boost::on_gray_target());
return graph::bfs_visitor_event_not_overridden();
}
template <class Edge, class Graph>
graph::bfs_visitor_event_not_overridden
black_target(Edge e, Graph& g)
{
invoke_visitors(m_vis, e, g, ::boost::on_black_target());
return graph::bfs_visitor_event_not_overridden();
}
template <class Vertex, class Graph>
graph::bfs_visitor_event_not_overridden
finish_vertex(Vertex u, Graph& g)
{
invoke_visitors(m_vis, u, g, ::boost::on_finish_vertex());
return graph::bfs_visitor_event_not_overridden();
}
BOOST_GRAPH_EVENT_STUB(on_initialize_vertex,bfs)
BOOST_GRAPH_EVENT_STUB(on_discover_vertex,bfs)
BOOST_GRAPH_EVENT_STUB(on_examine_vertex,bfs)
BOOST_GRAPH_EVENT_STUB(on_examine_edge,bfs)
BOOST_GRAPH_EVENT_STUB(on_tree_edge,bfs)
BOOST_GRAPH_EVENT_STUB(on_non_tree_edge,bfs)
BOOST_GRAPH_EVENT_STUB(on_gray_target,bfs)
BOOST_GRAPH_EVENT_STUB(on_black_target,bfs)
BOOST_GRAPH_EVENT_STUB(on_finish_vertex,bfs)
protected:
Visitors m_vis;
};
template <class Visitors>
bfs_visitor<Visitors>
make_bfs_visitor(Visitors vis) {
return bfs_visitor<Visitors>(vis);
}
typedef bfs_visitor<> default_bfs_visitor;
namespace detail {
template <class VertexListGraph, class ColorMap, class BFSVisitor,
class P, class T, class R>
void bfs_helper
(VertexListGraph& g,
typename graph_traits<VertexListGraph>::vertex_descriptor s,
ColorMap color,
BFSVisitor vis,
const bgl_named_params<P, T, R>& params,
boost::mpl::false_)
{
typedef graph_traits<VertexListGraph> Traits;
// Buffer default
typedef typename Traits::vertex_descriptor Vertex;
typedef boost::queue<Vertex> queue_t;
queue_t Q;
breadth_first_search
(g, s,
choose_param(get_param(params, buffer_param_t()), boost::ref(Q)).get(),
vis, color);
}
#ifdef BOOST_GRAPH_USE_MPI
template <class DistributedGraph, class ColorMap, class BFSVisitor,
class P, class T, class R>
void bfs_helper
(DistributedGraph& g,
typename graph_traits<DistributedGraph>::vertex_descriptor s,
ColorMap color,
BFSVisitor vis,
const bgl_named_params<P, T, R>& params,
boost::mpl::true_);
#endif // BOOST_GRAPH_USE_MPI
//-------------------------------------------------------------------------
// 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 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)
{
bfs_helper
(g, s, color,
choose_param(get_param(params, graph_visitor),
make_bfs_visitor(null_visitor())),
params,
boost::mpl::bool_<
boost::is_base_and_derived<
distributed_graph_tag,
typename graph_traits<VertexListGraph>::traversal_category>::value>());
}
};
template <>
struct 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)
{
null_visitor null_vis;
bfs_helper
(g, s,
make_two_bit_color_map
(num_vertices(g),
choose_const_pmap(get_param(params, vertex_index),
g, vertex_index)),
choose_param(get_param(params, graph_visitor),
make_bfs_visitor(null_vis)),
params,
boost::mpl::bool_<
boost::is_base_and_derived<
distributed_graph_tag,
typename graph_traits<VertexListGraph>::traversal_category>::value>());
}
};
} // namespace detail
#if 1
// Named Parameter Variant
template <class VertexListGraph, class P, class T, class R>
void 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::bfs_dispatch<C>::apply(ng, s, params,
get_param(params, vertex_color));
}
#endif
// This version does not initialize colors, user has to.
template <class IncidenceGraph, class P, class T, class R>
void breadth_first_visit
(const IncidenceGraph& g,
typename graph_traits<IncidenceGraph>::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.
IncidenceGraph& ng = const_cast<IncidenceGraph&>(g);
typedef graph_traits<IncidenceGraph> Traits;
// Buffer default
typedef typename Traits::vertex_descriptor vertex_descriptor;
typedef boost::queue<vertex_descriptor> queue_t;
queue_t Q;
breadth_first_visit
(ng, s,
choose_param(get_param(params, buffer_param_t()), boost::ref(Q)).get(),
choose_param(get_param(params, graph_visitor),
make_bfs_visitor(null_visitor())),
choose_pmap(get_param(params, vertex_color), ng, vertex_color)
);
}
namespace graph {
namespace detail {
template <typename Graph, typename Source>
struct breadth_first_search_impl {
typedef void result_type;
template <typename ArgPack>
void operator()(const Graph& g, const Source& source, const ArgPack& arg_pack) {
using namespace boost::graph::keywords;
typename boost::graph_traits<Graph>::vertex_descriptor sources[1] = {source};
boost::queue<typename boost::graph_traits<Graph>::vertex_descriptor> Q;
boost::breadth_first_search(g,
&sources[0],
&sources[1],
boost::unwrap_ref(arg_pack[_buffer | boost::ref(Q)]),
arg_pack[_visitor | make_bfs_visitor(null_visitor())],
boost::detail::make_color_map_from_arg_pack(g, arg_pack));
}
};
}
BOOST_GRAPH_MAKE_FORWARDING_FUNCTION(breadth_first_search, 2, 4)
}
#if 0
// Named Parameter Variant
BOOST_GRAPH_MAKE_OLD_STYLE_PARAMETER_FUNCTION(breadth_first_search, 2)
#endif
} // namespace boost
#include BOOST_GRAPH_MPI_INCLUDE(<boost/graph/distributed/breadth_first_search.hpp>)
#endif // BOOST_GRAPH_BREADTH_FIRST_SEARCH_HPP