Chris@16: //=======================================================================
Chris@16: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
Chris@16: // Copyright 2003 Bruce Barr
Chris@16: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //=======================================================================
Chris@16: 
Chris@16: // Nonrecursive implementation of depth_first_visit_impl submitted by
Chris@16: // Bruce Barr, schmoost <at> yahoo.com, May/June 2003.
Chris@16: #ifndef BOOST_GRAPH_RECURSIVE_DFS_HPP
Chris@16: #define BOOST_GRAPH_RECURSIVE_DFS_HPP
Chris@16: 
Chris@16: #include <boost/config.hpp>
Chris@16: #include <boost/graph/graph_traits.hpp>
Chris@16: #include <boost/graph/graph_concepts.hpp>
Chris@16: #include <boost/graph/properties.hpp>
Chris@16: #include <boost/graph/visitors.hpp>
Chris@16: #include <boost/graph/named_function_params.hpp>
Chris@16: #include <boost/ref.hpp>
Chris@16: #include <boost/implicit_cast.hpp>
Chris@16: #include <boost/optional.hpp>
Chris@16: #include <boost/parameter.hpp>
Chris@16: #include <boost/concept/assert.hpp>
Chris@16: #include <boost/tti/has_member_function.hpp>
Chris@16: 
Chris@16: #include <vector>
Chris@16: #include <utility>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16:   template <class Visitor, class Graph>
Chris@16:   class DFSVisitorConcept {
Chris@16:   public:
Chris@16:     void constraints() {
Chris@16:       BOOST_CONCEPT_ASSERT(( CopyConstructibleConcept<Visitor> ));
Chris@16:       vis.initialize_vertex(u, g);
Chris@16:       vis.start_vertex(u, g);
Chris@16:       vis.discover_vertex(u, g);
Chris@16:       vis.examine_edge(e, g);
Chris@16:       vis.tree_edge(e, g);
Chris@16:       vis.back_edge(e, g);
Chris@16:       vis.forward_or_cross_edge(e, g);
Chris@16:       // vis.finish_edge(e, g); // Optional for user
Chris@16:       vis.finish_vertex(u, g);
Chris@16:     }
Chris@16:   private:
Chris@16:     Visitor vis;
Chris@16:     Graph g;
Chris@16:     typename graph_traits<Graph>::vertex_descriptor u;
Chris@16:     typename graph_traits<Graph>::edge_descriptor e;
Chris@16:   };
Chris@16: 
Chris@16:   namespace detail {
Chris@16: 
Chris@16:     struct nontruth2 {
Chris@16:       template<class T, class T2>
Chris@16:       bool operator()(const T&, const T2&) const { return false; }
Chris@16:     };
Chris@16: 
Chris@16:     BOOST_TTI_HAS_MEMBER_FUNCTION(finish_edge)
Chris@16: 
Chris@16:     template <bool IsCallable> struct do_call_finish_edge {
Chris@16:       template <typename E, typename G, typename Vis>
Chris@16:       static void call_finish_edge(Vis& vis, const E& e, const G& g) {
Chris@16:         vis.finish_edge(e, g);
Chris@16:       }
Chris@16:     };
Chris@16: 
Chris@16:     template <> struct do_call_finish_edge<false> {
Chris@16:       template <typename E, typename G, typename Vis>
Chris@16:       static void call_finish_edge(Vis&, const E&, const G&) {}
Chris@16:     };
Chris@16: 
Chris@16:     template <typename E, typename G, typename Vis>
Chris@16:     void call_finish_edge(Vis& vis, const E& e, const G& g) { // Only call if method exists
Chris@16:       do_call_finish_edge<has_member_function_finish_edge<Vis, void>::value>::call_finish_edge(vis, e, g);
Chris@16:     }
Chris@16: 
Chris@16: 
Chris@16: // Define BOOST_RECURSIVE_DFS to use older, recursive version.
Chris@16: // It is retained for a while in order to perform performance
Chris@16: // comparison.
Chris@16: #ifndef BOOST_RECURSIVE_DFS
Chris@16: 
Chris@16:     // If the vertex u and the iterators ei and ei_end are thought of as the
Chris@16:     // context of the algorithm, each push and pop from the stack could
Chris@16:     // be thought of as a context shift.
Chris@16:     // Each pass through "while (ei != ei_end)" may refer to the out-edges of
Chris@16:     // an entirely different vertex, because the context of the algorithm
Chris@16:     // shifts every time a white adjacent vertex is discovered.
Chris@16:     // The corresponding context shift back from the adjacent vertex occurs
Chris@16:     // after all of its out-edges have been examined.
Chris@16:     //
Chris@16:     // See http://lists.boost.org/MailArchives/boost/msg48752.php for FAQ.
Chris@16: 
Chris@16:     template <class IncidenceGraph, class DFSVisitor, class ColorMap,
Chris@16:             class TerminatorFunc>
Chris@16:     void depth_first_visit_impl
Chris@16:       (const IncidenceGraph& g,
Chris@16:        typename graph_traits<IncidenceGraph>::vertex_descriptor u,
Chris@16:        DFSVisitor& vis,
Chris@16:        ColorMap color, TerminatorFunc func = TerminatorFunc())
Chris@16:     {
Chris@16:       BOOST_CONCEPT_ASSERT(( IncidenceGraphConcept<IncidenceGraph> ));
Chris@16:       BOOST_CONCEPT_ASSERT(( DFSVisitorConcept<DFSVisitor, IncidenceGraph> ));
Chris@16:       typedef typename graph_traits<IncidenceGraph>::vertex_descriptor Vertex;
Chris@16:       typedef typename graph_traits<IncidenceGraph>::edge_descriptor Edge;
Chris@16:       BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<ColorMap, Vertex> ));
Chris@16:       typedef typename property_traits<ColorMap>::value_type ColorValue;
Chris@16:       BOOST_CONCEPT_ASSERT(( ColorValueConcept<ColorValue> ));
Chris@16:       typedef color_traits<ColorValue> Color;
Chris@16:       typedef typename graph_traits<IncidenceGraph>::out_edge_iterator Iter;
Chris@16:       typedef std::pair<Vertex, std::pair<boost::optional<Edge>, std::pair<Iter, Iter> > > VertexInfo;
Chris@16: 
Chris@16:       boost::optional<Edge> src_e;
Chris@16:       Iter ei, ei_end;
Chris@16:       std::vector<VertexInfo> stack;
Chris@16: 
Chris@16:       // Possible optimization for vector
Chris@16:       //stack.reserve(num_vertices(g));
Chris@16: 
Chris@16:       put(color, u, Color::gray());
Chris@16:       vis.discover_vertex(u, g);
Chris@16:       boost::tie(ei, ei_end) = out_edges(u, g);
Chris@16:       if (func(u, g)) {
Chris@16:           // If this vertex terminates the search, we push empty range
Chris@16:           stack.push_back(std::make_pair(u, std::make_pair(boost::optional<Edge>(), std::make_pair(ei_end, ei_end))));
Chris@16:       } else {
Chris@16:           stack.push_back(std::make_pair(u, std::make_pair(boost::optional<Edge>(), std::make_pair(ei, ei_end))));
Chris@16:       }
Chris@16:       while (!stack.empty()) {
Chris@16:         VertexInfo& back = stack.back();
Chris@16:         u = back.first;
Chris@16:         src_e = back.second.first;
Chris@16:         boost::tie(ei, ei_end) = back.second.second;
Chris@16:         stack.pop_back();
Chris@16:         while (ei != ei_end) {
Chris@16:           Vertex v = target(*ei, g);
Chris@16:           vis.examine_edge(*ei, g);
Chris@16:           ColorValue v_color = get(color, v);
Chris@16:           if (v_color == Color::white()) {
Chris@16:             vis.tree_edge(*ei, g);
Chris@16:             src_e = *ei;
Chris@16:             stack.push_back(std::make_pair(u, std::make_pair(src_e, std::make_pair(++ei, ei_end))));
Chris@16:             u = v;
Chris@16:             put(color, u, Color::gray());
Chris@16:             vis.discover_vertex(u, g);
Chris@16:             boost::tie(ei, ei_end) = out_edges(u, g);
Chris@16:             if (func(u, g)) {
Chris@16:                 ei = ei_end;
Chris@16:             }
Chris@16:           } else {
Chris@16:             if (v_color == Color::gray()) {
Chris@16:               vis.back_edge(*ei, g);
Chris@16:             } else {
Chris@16:               vis.forward_or_cross_edge(*ei, g);
Chris@16:             }
Chris@16:             call_finish_edge(vis, *ei, g);
Chris@16:             ++ei;
Chris@16:           }
Chris@16:         }
Chris@16:         put(color, u, Color::black());
Chris@16:         vis.finish_vertex(u, g);
Chris@16:         if (src_e) call_finish_edge(vis, src_e.get(), g);
Chris@16:       }
Chris@16:     }
Chris@16: 
Chris@16: #else // BOOST_RECURSIVE_DFS is defined
Chris@16: 
Chris@16:     template <class IncidenceGraph, class DFSVisitor, class ColorMap,
Chris@16:               class TerminatorFunc>
Chris@16:     void depth_first_visit_impl
Chris@16:       (const IncidenceGraph& g,
Chris@16:        typename graph_traits<IncidenceGraph>::vertex_descriptor u,
Chris@16:        DFSVisitor& vis,  // pass-by-reference here, important!
Chris@16:        ColorMap color, TerminatorFunc func)
Chris@16:     {
Chris@16:       BOOST_CONCEPT_ASSERT(( IncidenceGraphConcept<IncidenceGraph> ));
Chris@16:       BOOST_CONCEPT_ASSERT(( DFSVisitorConcept<DFSVisitor, IncidenceGraph> ));
Chris@16:       typedef typename graph_traits<IncidenceGraph>::vertex_descriptor Vertex;
Chris@16:       BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<ColorMap, Vertex> ));
Chris@16:       typedef typename property_traits<ColorMap>::value_type ColorValue;
Chris@16:       BOOST_CONCEPT_ASSERT(( ColorValueConcept<ColorValue> ));
Chris@16:       typedef color_traits<ColorValue> Color;
Chris@16:       typename graph_traits<IncidenceGraph>::out_edge_iterator ei, ei_end;
Chris@16: 
Chris@16:       put(color, u, Color::gray());          vis.discover_vertex(u, g);
Chris@16: 
Chris@16:       if (!func(u, g))
Chris@16:         for (boost::tie(ei, ei_end) = out_edges(u, g); ei != ei_end; ++ei) {
Chris@16:           Vertex v = target(*ei, g);           vis.examine_edge(*ei, g);
Chris@16:           ColorValue v_color = get(color, v);
Chris@16:           if (v_color == Color::white()) {     vis.tree_edge(*ei, g);
Chris@16:           depth_first_visit_impl(g, v, vis, color, func);
Chris@16:           } else if (v_color == Color::gray()) vis.back_edge(*ei, g);
Chris@16:           else                                 vis.forward_or_cross_edge(*ei, g);
Chris@16:           call_finish_edge(vis, *ei, g);
Chris@16:         }
Chris@16:       put(color, u, Color::black());         vis.finish_vertex(u, g);
Chris@16:     }
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16:   } // namespace detail
Chris@16: 
Chris@16:   template <class VertexListGraph, class DFSVisitor, class ColorMap>
Chris@16:   void
Chris@16:   depth_first_search(const VertexListGraph& g, DFSVisitor vis, ColorMap color,
Chris@16:                      typename graph_traits<VertexListGraph>::vertex_descriptor start_vertex)
Chris@16:   {
Chris@16:     typedef typename graph_traits<VertexListGraph>::vertex_descriptor Vertex;
Chris@16:     BOOST_CONCEPT_ASSERT(( DFSVisitorConcept<DFSVisitor, VertexListGraph> ));
Chris@16:     typedef typename property_traits<ColorMap>::value_type ColorValue;
Chris@16:     typedef color_traits<ColorValue> Color;
Chris@16: 
Chris@16:     typename graph_traits<VertexListGraph>::vertex_iterator ui, ui_end;
Chris@16:     for (boost::tie(ui, ui_end) = vertices(g); ui != ui_end; ++ui) {
Chris@16:       Vertex u = implicit_cast<Vertex>(*ui);
Chris@16:       put(color, u, Color::white()); vis.initialize_vertex(u, g);
Chris@16:     }
Chris@16: 
Chris@16:     if (start_vertex != detail::get_default_starting_vertex(g)){ vis.start_vertex(start_vertex, g);
Chris@16:       detail::depth_first_visit_impl(g, start_vertex, vis, color,
Chris@16:                                      detail::nontruth2());
Chris@16:     }
Chris@16: 
Chris@16:     for (boost::tie(ui, ui_end) = vertices(g); ui != ui_end; ++ui) {
Chris@16:       Vertex u = implicit_cast<Vertex>(*ui);
Chris@16:       ColorValue u_color = get(color, u);
Chris@16:       if (u_color == Color::white()) {       vis.start_vertex(u, g);
Chris@16:         detail::depth_first_visit_impl(g, u, vis, color, detail::nontruth2());
Chris@16:       }
Chris@16:     }
Chris@16:   }
Chris@16: 
Chris@16:   template <class VertexListGraph, class DFSVisitor, class ColorMap>
Chris@16:   void
Chris@16:   depth_first_search(const VertexListGraph& g, DFSVisitor vis, ColorMap color)
Chris@16:   {
Chris@16:     typedef typename boost::graph_traits<VertexListGraph>::vertex_iterator vi;
Chris@16:     std::pair<vi, vi> verts = vertices(g);
Chris@16:     if (verts.first == verts.second)
Chris@16:       return;
Chris@16: 
Chris@16:     depth_first_search(g, vis, color, detail::get_default_starting_vertex(g));
Chris@16:   }
Chris@16: 
Chris@16:   template <class Visitors = null_visitor>
Chris@16:   class dfs_visitor {
Chris@16:   public:
Chris@16:     dfs_visitor() { }
Chris@16:     dfs_visitor(Visitors vis) : m_vis(vis) { }
Chris@16: 
Chris@16:     template <class Vertex, class Graph>
Chris@16:     void initialize_vertex(Vertex u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_initialize_vertex());
Chris@16:     }
Chris@16:     template <class Vertex, class Graph>
Chris@16:     void start_vertex(Vertex u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_start_vertex());
Chris@16:     }
Chris@16:     template <class Vertex, class Graph>
Chris@16:     void discover_vertex(Vertex u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_discover_vertex());
Chris@16:     }
Chris@16:     template <class Edge, class Graph>
Chris@16:     void examine_edge(Edge u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_examine_edge());
Chris@16:     }
Chris@16:     template <class Edge, class Graph>
Chris@16:     void tree_edge(Edge u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_tree_edge());
Chris@16:     }
Chris@16:     template <class Edge, class Graph>
Chris@16:     void back_edge(Edge u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_back_edge());
Chris@16:     }
Chris@16:     template <class Edge, class Graph>
Chris@16:     void forward_or_cross_edge(Edge u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_forward_or_cross_edge());
Chris@16:     }
Chris@16:     template <class Edge, class Graph>
Chris@16:     void finish_edge(Edge u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_finish_edge());
Chris@16:     }
Chris@16:     template <class Vertex, class Graph>
Chris@16:     void finish_vertex(Vertex u, const Graph& g) {
Chris@16:       invoke_visitors(m_vis, u, g, ::boost::on_finish_vertex());
Chris@16:     }
Chris@16: 
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_initialize_vertex,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_start_vertex,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_discover_vertex,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_examine_edge,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_tree_edge,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_back_edge,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_forward_or_cross_edge,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_finish_edge,dfs)
Chris@16:     BOOST_GRAPH_EVENT_STUB(on_finish_vertex,dfs)
Chris@16: 
Chris@16:   protected:
Chris@16:     Visitors m_vis;
Chris@16:   };
Chris@16:   template <class Visitors>
Chris@16:   dfs_visitor<Visitors>
Chris@16:   make_dfs_visitor(Visitors vis) {
Chris@16:     return dfs_visitor<Visitors>(vis);
Chris@16:   }
Chris@16:   typedef dfs_visitor<> default_dfs_visitor;
Chris@16: 
Chris@16:   // Boost.Parameter named parameter variant
Chris@16:   namespace graph {
Chris@16:     namespace detail {
Chris@16:       template <typename Graph>
Chris@16:       struct depth_first_search_impl {
Chris@16:         typedef void result_type;
Chris@16:         template <typename ArgPack>
Chris@16:         void operator()(const Graph& g, const ArgPack& arg_pack) const {
Chris@16:           using namespace boost::graph::keywords;
Chris@16:           boost::depth_first_search(g,
Chris@16:                                     arg_pack[_visitor | make_dfs_visitor(null_visitor())],
Chris@16:                                     boost::detail::make_color_map_from_arg_pack(g, arg_pack),
Chris@16:                                     arg_pack[_root_vertex || boost::detail::get_default_starting_vertex_t<Graph>(g)]);
Chris@16:         }
Chris@16:       };
Chris@16:     }
Chris@16:     BOOST_GRAPH_MAKE_FORWARDING_FUNCTION(depth_first_search, 1, 4)
Chris@16:   }
Chris@16: 
Chris@16:   BOOST_GRAPH_MAKE_OLD_STYLE_PARAMETER_FUNCTION(depth_first_search, 1)
Chris@16: 
Chris@16:   template <class IncidenceGraph, class DFSVisitor, class ColorMap>
Chris@16:   void depth_first_visit
Chris@16:     (const IncidenceGraph& g,
Chris@16:      typename graph_traits<IncidenceGraph>::vertex_descriptor u,
Chris@16:      DFSVisitor vis, ColorMap color)
Chris@16:   {
Chris@16:     vis.start_vertex(u, g);
Chris@16:     detail::depth_first_visit_impl(g, u, vis, color, detail::nontruth2());
Chris@16:   }
Chris@16: 
Chris@16:   template <class IncidenceGraph, class DFSVisitor, class ColorMap,
Chris@16:             class TerminatorFunc>
Chris@16:   void depth_first_visit
Chris@16:     (const IncidenceGraph& g,
Chris@16:      typename graph_traits<IncidenceGraph>::vertex_descriptor u,
Chris@16:      DFSVisitor vis, ColorMap color, TerminatorFunc func = TerminatorFunc())
Chris@16:   {
Chris@16:     vis.start_vertex(u, g);
Chris@16:     detail::depth_first_visit_impl(g, u, vis, color, func);
Chris@16:   }
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #ifdef BOOST_GRAPH_USE_MPI
Chris@16: #  include <boost/graph/distributed/depth_first_search.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: #endif