344 lines
13 KiB
C++
344 lines
13 KiB
C++
//
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//=======================================================================
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// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
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// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//=======================================================================
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//
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#ifndef BOOST_GRAPH_STRONG_COMPONENTS_HPP
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#define BOOST_GRAPH_STRONG_COMPONENTS_HPP
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#include <stack>
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#include <boost/config.hpp>
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#include <boost/graph/depth_first_search.hpp>
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#include <boost/type_traits/conversion_traits.hpp>
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#include <boost/static_assert.hpp>
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#include <boost/graph/overloading.hpp>
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#include <boost/concept/assert.hpp>
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namespace boost {
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//==========================================================================
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// This is Tarjan's algorithm for strongly connected components
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// from his paper "Depth first search and linear graph algorithms".
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// It calculates the components in a single application of DFS.
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// We implement the algorithm as a dfs-visitor.
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namespace detail {
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template <typename ComponentMap, typename RootMap, typename DiscoverTime,
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typename Stack>
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class tarjan_scc_visitor : public dfs_visitor<>
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{
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typedef typename property_traits<ComponentMap>::value_type comp_type;
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typedef typename property_traits<DiscoverTime>::value_type time_type;
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public:
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tarjan_scc_visitor(ComponentMap comp_map, RootMap r, DiscoverTime d,
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comp_type& c_, Stack& s_)
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: c(c_), comp(comp_map), root(r), discover_time(d),
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dfs_time(time_type()), s(s_) { }
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template <typename Graph>
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void discover_vertex(typename graph_traits<Graph>::vertex_descriptor v,
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const Graph&) {
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put(root, v, v);
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put(comp, v, (std::numeric_limits<comp_type>::max)());
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put(discover_time, v, dfs_time++);
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s.push(v);
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}
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template <typename Graph>
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void finish_vertex(typename graph_traits<Graph>::vertex_descriptor v,
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const Graph& g) {
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typename graph_traits<Graph>::vertex_descriptor w;
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typename graph_traits<Graph>::out_edge_iterator ei, ei_end;
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for (boost::tie(ei, ei_end) = out_edges(v, g); ei != ei_end; ++ei) {
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w = target(*ei, g);
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if (get(comp, w) == (std::numeric_limits<comp_type>::max)())
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put(root, v, this->min_discover_time(get(root,v), get(root,w)));
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}
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if (get(root, v) == v) {
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do {
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w = s.top(); s.pop();
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put(comp, w, c);
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put(root, w, v);
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} while (w != v);
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++c;
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}
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}
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private:
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template <typename Vertex>
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Vertex min_discover_time(Vertex u, Vertex v) {
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return get(discover_time, u) < get(discover_time,v) ? u : v;
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}
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comp_type& c;
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ComponentMap comp;
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RootMap root;
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DiscoverTime discover_time;
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time_type dfs_time;
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Stack& s;
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};
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template <class Graph, class ComponentMap, class RootMap,
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class DiscoverTime, class P, class T, class R>
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typename property_traits<ComponentMap>::value_type
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strong_components_impl
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(const Graph& g, // Input
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ComponentMap comp, // Output
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// Internal record keeping
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RootMap root,
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DiscoverTime discover_time,
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const bgl_named_params<P, T, R>& params)
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{
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typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
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BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<ComponentMap, Vertex> ));
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BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<RootMap, Vertex> ));
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typedef typename property_traits<RootMap>::value_type RootV;
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BOOST_CONCEPT_ASSERT(( ConvertibleConcept<RootV, Vertex> ));
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BOOST_CONCEPT_ASSERT(( ReadWritePropertyMapConcept<DiscoverTime, Vertex> ));
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typename property_traits<ComponentMap>::value_type total = 0;
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std::stack<Vertex> s;
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detail::tarjan_scc_visitor<ComponentMap, RootMap, DiscoverTime,
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std::stack<Vertex> >
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vis(comp, root, discover_time, total, s);
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depth_first_search(g, params.visitor(vis));
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return total;
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}
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//-------------------------------------------------------------------------
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// The dispatch functions handle the defaults for the rank and discover
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// time property maps.
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// dispatch with class specialization to avoid VC++ bug
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template <class DiscoverTimeMap>
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struct strong_comp_dispatch2 {
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template <class Graph, class ComponentMap, class RootMap, class P, class T, class R>
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inline static typename property_traits<ComponentMap>::value_type
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apply(const Graph& g,
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ComponentMap comp,
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RootMap r_map,
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const bgl_named_params<P, T, R>& params,
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DiscoverTimeMap time_map)
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{
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return strong_components_impl(g, comp, r_map, time_map, params);
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}
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};
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template <>
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struct strong_comp_dispatch2<param_not_found> {
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template <class Graph, class ComponentMap, class RootMap,
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class P, class T, class R>
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inline static typename property_traits<ComponentMap>::value_type
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apply(const Graph& g,
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ComponentMap comp,
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RootMap r_map,
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const bgl_named_params<P, T, R>& params,
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param_not_found)
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{
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typedef typename graph_traits<Graph>::vertices_size_type size_type;
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size_type n = num_vertices(g) > 0 ? num_vertices(g) : 1;
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std::vector<size_type> time_vec(n);
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return strong_components_impl
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(g, comp, r_map,
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make_iterator_property_map(time_vec.begin(), choose_const_pmap
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(get_param(params, vertex_index),
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g, vertex_index), time_vec[0]),
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params);
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}
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};
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template <class Graph, class ComponentMap, class RootMap,
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class P, class T, class R, class DiscoverTimeMap>
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inline typename property_traits<ComponentMap>::value_type
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scc_helper2(const Graph& g,
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ComponentMap comp,
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RootMap r_map,
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const bgl_named_params<P, T, R>& params,
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DiscoverTimeMap time_map)
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{
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return strong_comp_dispatch2<DiscoverTimeMap>::apply(g, comp, r_map, params, time_map);
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}
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template <class RootMap>
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struct strong_comp_dispatch1 {
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template <class Graph, class ComponentMap, class P, class T, class R>
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inline static typename property_traits<ComponentMap>::value_type
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apply(const Graph& g,
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ComponentMap comp,
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const bgl_named_params<P, T, R>& params,
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RootMap r_map)
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{
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return scc_helper2(g, comp, r_map, params, get_param(params, vertex_discover_time));
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}
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};
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template <>
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struct strong_comp_dispatch1<param_not_found> {
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template <class Graph, class ComponentMap,
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class P, class T, class R>
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inline static typename property_traits<ComponentMap>::value_type
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apply(const Graph& g,
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ComponentMap comp,
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const bgl_named_params<P, T, R>& params,
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param_not_found)
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{
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typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
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typename std::vector<Vertex>::size_type
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n = num_vertices(g) > 0 ? num_vertices(g) : 1;
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std::vector<Vertex> root_vec(n);
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return scc_helper2
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(g, comp,
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make_iterator_property_map(root_vec.begin(), choose_const_pmap
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(get_param(params, vertex_index),
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g, vertex_index), root_vec[0]),
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params,
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get_param(params, vertex_discover_time));
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}
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};
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template <class Graph, class ComponentMap, class RootMap,
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class P, class T, class R>
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inline typename property_traits<ComponentMap>::value_type
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scc_helper1(const Graph& g,
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ComponentMap comp,
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const bgl_named_params<P, T, R>& params,
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RootMap r_map)
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{
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return detail::strong_comp_dispatch1<RootMap>::apply(g, comp, params,
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r_map);
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}
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} // namespace detail
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template <class Graph, class ComponentMap,
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class P, class T, class R>
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inline typename property_traits<ComponentMap>::value_type
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strong_components(const Graph& g, ComponentMap comp,
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const bgl_named_params<P, T, R>& params
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BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, vertex_list_graph_tag))
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{
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typedef typename graph_traits<Graph>::directed_category DirCat;
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BOOST_STATIC_ASSERT((is_convertible<DirCat*, directed_tag*>::value == true));
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return detail::scc_helper1(g, comp, params,
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get_param(params, vertex_root_t()));
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}
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template <class Graph, class ComponentMap>
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inline typename property_traits<ComponentMap>::value_type
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strong_components(const Graph& g, ComponentMap comp
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BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, vertex_list_graph_tag))
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{
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typedef typename graph_traits<Graph>::directed_category DirCat;
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BOOST_STATIC_ASSERT((is_convertible<DirCat*, directed_tag*>::value == true));
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bgl_named_params<int, int> params(0);
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return strong_components(g, comp, params);
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}
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template <typename Graph, typename ComponentMap, typename ComponentLists>
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void build_component_lists
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(const Graph& g,
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typename graph_traits<Graph>::vertices_size_type num_scc,
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ComponentMap component_number,
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ComponentLists& components)
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{
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components.resize(num_scc);
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typename graph_traits<Graph>::vertex_iterator vi, vi_end;
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for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
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components[component_number[*vi]].push_back(*vi);
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}
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} // namespace boost
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#include <queue>
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#include <vector>
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#include <boost/graph/transpose_graph.hpp>
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#include <boost/pending/indirect_cmp.hpp>
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#include <boost/graph/connected_components.hpp> // for components_recorder
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namespace boost {
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//==========================================================================
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// This is the version of strongly connected components from
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// "Intro. to Algorithms" by Cormen, Leiserson, Rivest, which was
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// adapted from "Data Structure and Algorithms" by Aho, Hopcroft,
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// and Ullman, who credit the algorithm to S.R. Kosaraju and M. Sharir.
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// The algorithm is based on computing DFS forests the graph
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// and its transpose.
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// This algorithm is slower than Tarjan's by a constant factor, uses
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// more memory, and puts more requirements on the graph type.
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template <class Graph, class DFSVisitor, class ComponentsMap,
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class DiscoverTime, class FinishTime,
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class ColorMap>
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typename property_traits<ComponentsMap>::value_type
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kosaraju_strong_components(Graph& G, ComponentsMap c,
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FinishTime finish_time, ColorMap color)
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{
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BOOST_CONCEPT_ASSERT(( MutableGraphConcept<Graph> ));
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// ...
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typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
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typedef typename property_traits<ColorMap>::value_type ColorValue;
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typedef color_traits<ColorValue> Color;
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typename property_traits<FinishTime>::value_type time = 0;
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depth_first_search
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(G, make_dfs_visitor(stamp_times(finish_time, time, on_finish_vertex())),
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color);
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Graph G_T(num_vertices(G));
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transpose_graph(G, G_T);
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typedef typename property_traits<ComponentsMap>::value_type count_type;
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count_type c_count(0);
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detail::components_recorder<ComponentsMap>
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vis(c, c_count);
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// initialize G_T
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typename graph_traits<Graph>::vertex_iterator ui, ui_end;
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for (boost::tie(ui, ui_end) = vertices(G_T); ui != ui_end; ++ui)
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put(color, *ui, Color::white());
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typedef typename property_traits<FinishTime>::value_type D;
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typedef indirect_cmp< FinishTime, std::less<D> > Compare;
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Compare fl(finish_time);
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std::priority_queue<Vertex, std::vector<Vertex>, Compare > Q(fl);
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typename graph_traits<Graph>::vertex_iterator i, j, iend, jend;
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boost::tie(i, iend) = vertices(G_T);
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boost::tie(j, jend) = vertices(G);
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for ( ; i != iend; ++i, ++j) {
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put(finish_time, *i, get(finish_time, *j));
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Q.push(*i);
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}
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while ( !Q.empty() ) {
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Vertex u = Q.top();
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Q.pop();
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if (get(color, u) == Color::white()) {
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depth_first_visit(G_T, u, vis, color);
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++c_count;
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}
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}
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return c_count;
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}
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} // namespace boost
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#ifdef BOOST_GRAPH_USE_MPI
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# include <boost/graph/distributed/strong_components.hpp>
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#endif
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#endif // BOOST_GRAPH_STRONG_COMPONENTS_HPP
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