| // |
| //======================================================================= |
| // 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 <boost/config.hpp> |
| #include <boost/ref.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> |
| |
| namespace boost { |
| |
| template <class Visitor, class Graph> |
| struct NeighborBFSVisitorConcept { |
| void constraints() { |
| function_requires< 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) |
| |
| { |
| function_requires< BidirectionalGraphConcept<BidirectionalGraph> >(); |
| typedef graph_traits<BidirectionalGraph> GTraits; |
| typedef typename GTraits::vertex_descriptor Vertex; |
| typedef typename GTraits::edge_descriptor Edge; |
| function_requires< |
| NeighborBFSVisitorConcept<BFSVisitor, BidirectionalGraph> >(); |
| function_requires< 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<detail::error_property_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, |
| detail::error_property_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 property_value< bgl_named_params<P,T,R>, |
| vertex_color_t>::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 |
| |