348 lines
13 KiB
C++
348 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/graph/detail/mpi_include.hpp>
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#include <boost/concept/assert.hpp>
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namespace boost
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{
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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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{
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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_)
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, comp(comp_map)
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, root(r)
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, discover_time(d)
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, dfs_time(time_type())
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, s(s_)
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{
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}
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template < typename Graph >
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void discover_vertex(
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typename graph_traits< Graph >::vertex_descriptor v, const Graph&)
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{
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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(
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typename graph_traits< Graph >::vertex_descriptor v, const Graph& g)
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{
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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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{
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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,
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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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{
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do
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{
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w = s.top();
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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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{
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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 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, 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(
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(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(
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(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 > struct strong_comp_dispatch2
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{
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template < class Graph, class ComponentMap, class RootMap, class P,
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class T, class R >
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inline static typename property_traits< ComponentMap >::value_type
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apply(const Graph& g, ComponentMap comp, RootMap r_map,
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const bgl_named_params< P, T, R >& params, 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 <> struct strong_comp_dispatch2< param_not_found >
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{
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template < class Graph, class ComponentMap, class RootMap, class P,
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class T, class R >
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inline static typename property_traits< ComponentMap >::value_type
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apply(const Graph& g, ComponentMap comp, RootMap r_map,
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const bgl_named_params< P, T, R >& params, param_not_found)
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{
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typedef
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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(g, comp, r_map,
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make_iterator_property_map(time_vec.begin(),
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choose_const_pmap(
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get_param(params, vertex_index), g, vertex_index),
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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, class P, class T,
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class R, class DiscoverTimeMap >
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inline typename property_traits< ComponentMap >::value_type scc_helper2(
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const Graph& g, ComponentMap comp, RootMap r_map,
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const bgl_named_params< P, T, R >& params, DiscoverTimeMap time_map)
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{
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return strong_comp_dispatch2< DiscoverTimeMap >::apply(
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g, comp, r_map, params, time_map);
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}
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template < class RootMap > struct strong_comp_dispatch1
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{
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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, ComponentMap comp,
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const bgl_named_params< P, T, R >& params, RootMap r_map)
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{
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return scc_helper2(g, comp, r_map, params,
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get_param(params, vertex_discover_time));
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}
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};
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template <> struct strong_comp_dispatch1< param_not_found >
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{
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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, ComponentMap comp,
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const bgl_named_params< P, T, R >& params, 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 n
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= 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(g, comp,
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make_iterator_property_map(root_vec.begin(),
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choose_const_pmap(
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get_param(params, vertex_index), g, vertex_index),
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root_vec[0]),
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params, 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, class P, class T,
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class R >
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inline typename property_traits< ComponentMap >::value_type scc_helper1(
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const Graph& g, ComponentMap comp,
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const bgl_named_params< P, T, R >& params, RootMap r_map)
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{
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return detail::strong_comp_dispatch1< RootMap >::apply(
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g, comp, params, r_map);
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}
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} // namespace detail
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template < class Graph, class ComponentMap, class P, class T, class R >
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inline typename property_traits< ComponentMap >::value_type strong_components(
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const Graph& g, ComponentMap comp,
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const bgl_named_params< P, T, R >& params BOOST_GRAPH_ENABLE_IF_MODELS_PARM(
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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(
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(is_convertible< DirCat*, directed_tag* >::value == true));
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return detail::scc_helper1(
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g, comp, params, 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 strong_components(
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const Graph& g,
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ComponentMap comp BOOST_GRAPH_ENABLE_IF_MODELS_PARM(
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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(
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(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(const Graph& g,
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typename graph_traits< Graph >::vertices_size_type num_scc,
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ComponentMap component_number, 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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//==========================================================================
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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, class ColorMap >
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typename property_traits< ComponentsMap >::value_type
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kosaraju_strong_components(
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Graph& G, ComponentsMap c, 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(G,
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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 > 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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{
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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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{
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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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{
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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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#include BOOST_GRAPH_MPI_INCLUDE(<boost/graph/distributed/strong_components.hpp>)
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#endif // BOOST_GRAPH_STRONG_COMPONENTS_HPP
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