Edit: /usr/include/boost/graph/strong_components.hpp (13009B)
//
//=======================================================================
// 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_STRONG_COMPONENTS_HPP
#define BOOST_GRAPH_STRONG_COMPONENTS_HPP
#include
#include
#include
#include
#include
#include
#include
#include
namespace boost
{
//==========================================================================
// This is Tarjan's algorithm for strongly connected components
// from his paper "Depth first search and linear graph algorithms".
// It calculates the components in a single application of DFS.
// We implement the algorithm as a dfs-visitor.
namespace detail
{
template < typename ComponentMap, typename RootMap, typename DiscoverTime,
typename Stack >
class tarjan_scc_visitor : public dfs_visitor<>
{
typedef typename property_traits< ComponentMap >::value_type comp_type;
typedef typename property_traits< DiscoverTime >::value_type time_type;
public:
tarjan_scc_visitor(ComponentMap comp_map, RootMap r, DiscoverTime d,
comp_type& c_, Stack& s_)
: c(c_)
, comp(comp_map)
, root(r)
, discover_time(d)
, dfs_time(time_type())
, s(s_)
{
}
template < typename Graph >
void discover_vertex(
typename graph_traits< Graph >::vertex_descriptor v, const Graph&)
{
put(root, v, v);
put(comp, v, (std::numeric_limits< comp_type >::max)());
put(discover_time, v, dfs_time++);
s.push(v);
}
template < typename Graph >
void finish_vertex(
typename graph_traits< Graph >::vertex_descriptor v, const Graph& g)
{
typename graph_traits< Graph >::vertex_descriptor w;
typename graph_traits< Graph >::out_edge_iterator ei, ei_end;
for (boost::tie(ei, ei_end) = out_edges(v, g); ei != ei_end; ++ei)
{
w = target(*ei, g);
if (get(comp, w) == (std::numeric_limits< comp_type >::max)())
put(root, v,
this->min_discover_time(get(root, v), get(root, w)));
}
if (get(root, v) == v)
{
do
{
w = s.top();
s.pop();
put(comp, w, c);
put(root, w, v);
} while (w != v);
++c;
}
}
private:
template < typename Vertex >
Vertex min_discover_time(Vertex u, Vertex v)
{
return get(discover_time, u) < get(discover_time, v) ? u : v;
}
comp_type& c;
ComponentMap comp;
RootMap root;
DiscoverTime discover_time;
time_type dfs_time;
Stack& s;
};
template < class Graph, class ComponentMap, class RootMap,
class DiscoverTime, class P, class T, class R >
typename property_traits< ComponentMap >::value_type strong_components_impl(
const Graph& g, // Input
ComponentMap comp, // Output
// Internal record keeping
RootMap root, DiscoverTime discover_time,
const bgl_named_params< P, T, R >& params)
{
typedef typename graph_traits< Graph >::vertex_descriptor Vertex;
BOOST_CONCEPT_ASSERT(
(ReadWritePropertyMapConcept< ComponentMap, Vertex >));
BOOST_CONCEPT_ASSERT((ReadWritePropertyMapConcept< RootMap, Vertex >));
typedef typename property_traits< RootMap >::value_type RootV;
BOOST_CONCEPT_ASSERT((ConvertibleConcept< RootV, Vertex >));
BOOST_CONCEPT_ASSERT(
(ReadWritePropertyMapConcept< DiscoverTime, Vertex >));
typename property_traits< ComponentMap >::value_type total = 0;
std::stack< Vertex > s;
detail::tarjan_scc_visitor< ComponentMap, RootMap, DiscoverTime,
std::stack< Vertex > >
vis(comp, root, discover_time, total, s);
depth_first_search(g, params.visitor(vis));
return total;
}
//-------------------------------------------------------------------------
// The dispatch functions handle the defaults for the rank and discover
// time property maps.
// dispatch with class specialization to avoid VC++ bug
template < class DiscoverTimeMap > struct strong_comp_dispatch2
{
template < class Graph, class ComponentMap, class RootMap, class P,
class T, class R >
inline static typename property_traits< ComponentMap >::value_type
apply(const Graph& g, ComponentMap comp, RootMap r_map,
const bgl_named_params< P, T, R >& params, DiscoverTimeMap time_map)
{
return strong_components_impl(g, comp, r_map, time_map, params);
}
};
template <> struct strong_comp_dispatch2< param_not_found >
{
template < class Graph, class ComponentMap, class RootMap, class P,
class T, class R >
inline static typename property_traits< ComponentMap >::value_type
apply(const Graph& g, ComponentMap comp, RootMap r_map,
const bgl_named_params< P, T, R >& params, param_not_found)
{
typedef
typename graph_traits< Graph >::vertices_size_type size_type;
size_type n = num_vertices(g) > 0 ? num_vertices(g) : 1;
std::vector< size_type > time_vec(n);
return strong_components_impl(g, comp, r_map,
make_iterator_property_map(time_vec.begin(),
choose_const_pmap(
get_param(params, vertex_index), g, vertex_index),
time_vec[0]),
params);
}
};
template < class Graph, class ComponentMap, class RootMap, class P, class T,
class R, class DiscoverTimeMap >
inline typename property_traits< ComponentMap >::value_type scc_helper2(
const Graph& g, ComponentMap comp, RootMap r_map,
const bgl_named_params< P, T, R >& params, DiscoverTimeMap time_map)
{
return strong_comp_dispatch2< DiscoverTimeMap >::apply(
g, comp, r_map, params, time_map);
}
template < class RootMap > struct strong_comp_dispatch1
{
template < class Graph, class ComponentMap, class P, class T, class R >
inline static typename property_traits< ComponentMap >::value_type
apply(const Graph& g, ComponentMap comp,
const bgl_named_params< P, T, R >& params, RootMap r_map)
{
return scc_helper2(g, comp, r_map, params,
get_param(params, vertex_discover_time));
}
};
template <> struct strong_comp_dispatch1< param_not_found >
{
template < class Graph, class ComponentMap, class P, class T, class R >
inline static typename property_traits< ComponentMap >::value_type
apply(const Graph& g, ComponentMap comp,
const bgl_named_params< P, T, R >& params, param_not_found)
{
typedef typename graph_traits< Graph >::vertex_descriptor Vertex;
typename std::vector< Vertex >::size_type n
= num_vertices(g) > 0 ? num_vertices(g) : 1;
std::vector< Vertex > root_vec(n);
return scc_helper2(g, comp,
make_iterator_property_map(root_vec.begin(),
choose_const_pmap(
get_param(params, vertex_index), g, vertex_index),
root_vec[0]),
params, get_param(params, vertex_discover_time));
}
};
template < class Graph, class ComponentMap, class RootMap, class P, class T,
class R >
inline typename property_traits< ComponentMap >::value_type scc_helper1(
const Graph& g, ComponentMap comp,
const bgl_named_params< P, T, R >& params, RootMap r_map)
{
return detail::strong_comp_dispatch1< RootMap >::apply(
g, comp, params, r_map);
}
} // namespace detail
template < class Graph, class ComponentMap, class P, class T, class R >
inline typename property_traits< ComponentMap >::value_type strong_components(
const Graph& g, ComponentMap comp,
const bgl_named_params< P, T, R >& params BOOST_GRAPH_ENABLE_IF_MODELS_PARM(
Graph, vertex_list_graph_tag))
{
typedef typename graph_traits< Graph >::directed_category DirCat;
BOOST_STATIC_ASSERT(
(is_convertible< DirCat*, directed_tag* >::value == true));
return detail::scc_helper1(
g, comp, params, get_param(params, vertex_root_t()));
}
template < class Graph, class ComponentMap >
inline typename property_traits< ComponentMap >::value_type strong_components(
const Graph& g,
ComponentMap comp BOOST_GRAPH_ENABLE_IF_MODELS_PARM(
Graph, vertex_list_graph_tag))
{
typedef typename graph_traits< Graph >::directed_category DirCat;
BOOST_STATIC_ASSERT(
(is_convertible< DirCat*, directed_tag* >::value == true));
bgl_named_params< int, int > params(0);
return strong_components(g, comp, params);
}
template < typename Graph, typename ComponentMap, typename ComponentLists >
void build_component_lists(const Graph& g,
typename graph_traits< Graph >::vertices_size_type num_scc,
ComponentMap component_number, ComponentLists& components)
{
components.resize(num_scc);
typename graph_traits< Graph >::vertex_iterator vi, vi_end;
for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
components[component_number[*vi]].push_back(*vi);
}
} // namespace boost
#include
#include
#include
#include
#include // for components_recorder
namespace boost
{
//==========================================================================
// This is the version of strongly connected components from
// "Intro. to Algorithms" by Cormen, Leiserson, Rivest, which was
// adapted from "Data Structure and Algorithms" by Aho, Hopcroft,
// and Ullman, who credit the algorithm to S.R. Kosaraju and M. Sharir.
// The algorithm is based on computing DFS forests the graph
// and its transpose.
// This algorithm is slower than Tarjan's by a constant factor, uses
// more memory, and puts more requirements on the graph type.
template < class Graph, class DFSVisitor, class ComponentsMap,
class DiscoverTime, class FinishTime, class ColorMap >
typename property_traits< ComponentsMap >::value_type
kosaraju_strong_components(
Graph& G, ComponentsMap c, FinishTime finish_time, ColorMap color)
{
BOOST_CONCEPT_ASSERT((MutableGraphConcept< Graph >));
// ...
typedef typename graph_traits< Graph >::vertex_descriptor Vertex;
typedef typename property_traits< ColorMap >::value_type ColorValue;
typedef color_traits< ColorValue > Color;
typename property_traits< FinishTime >::value_type time = 0;
depth_first_search(G,
make_dfs_visitor(stamp_times(finish_time, time, on_finish_vertex())),
color);
Graph G_T(num_vertices(G));
transpose_graph(G, G_T);
typedef typename property_traits< ComponentsMap >::value_type count_type;
count_type c_count(0);
detail::components_recorder< ComponentsMap > vis(c, c_count);
// initialize G_T
typename graph_traits< Graph >::vertex_iterator ui, ui_end;
for (boost::tie(ui, ui_end) = vertices(G_T); ui != ui_end; ++ui)
put(color, *ui, Color::white());
typedef typename property_traits< FinishTime >::value_type D;
typedef indirect_cmp< FinishTime, std::less< D > > Compare;
Compare fl(finish_time);
std::priority_queue< Vertex, std::vector< Vertex >, Compare > Q(fl);
typename graph_traits< Graph >::vertex_iterator i, j, iend, jend;
boost::tie(i, iend) = vertices(G_T);
boost::tie(j, jend) = vertices(G);
for (; i != iend; ++i, ++j)
{
put(finish_time, *i, get(finish_time, *j));
Q.push(*i);
}
while (!Q.empty())
{
Vertex u = Q.top();
Q.pop();
if (get(color, u) == Color::white())
{
depth_first_visit(G_T, u, vis, color);
++c_count;
}
}
return c_count;
}
} // namespace boost
#include BOOST_GRAPH_MPI_INCLUDE()
#endif // BOOST_GRAPH_STRONG_COMPONENTS_HPP