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/concept/assert.hpp> #ifdef BOOST_GRAPH_USE_MPI #include <boost/graph/distributed/concepts.hpp> #endif // BOOST_GRAPH_USE_MPI 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 #ifdef BOOST_GRAPH_USE_MPI # include <boost/graph/distributed/breadth_first_search.hpp> #endif #endif // BOOST_GRAPH_BREADTH_FIRST_SEARCH_HPP