--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/epoc32/include/stdapis/boost/graph/strong_components.hpp Tue Mar 16 16:12:26 2010 +0000
@@ -0,0 +1,334 @@
+//
+//=======================================================================
+// 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 <stack>
+#include <boost/config.hpp>
+#include <boost/graph/depth_first_search.hpp>
+#include <boost/type_traits/conversion_traits.hpp>
+#include <boost/static_assert.hpp>
+
+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 (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);
+ } 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;
+ function_requires< ReadWritePropertyMapConcept<ComponentMap, Vertex> >();
+ function_requires< ReadWritePropertyMapConcept<RootMap, Vertex> >();
+ typedef typename property_traits<RootMap>::value_type RootV;
+ function_requires< ConvertibleConcept<RootV, Vertex> >();
+ function_requires< 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<detail::error_property_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,
+ detail::error_property_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<detail::error_property_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,
+ detail::error_property_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)
+ {
+ 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)
+ {
+ 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 (tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
+ components[component_number[*vi]].push_back(*vi);
+ }
+
+
+} // namespace boost
+
+#include <queue>
+#include <vector>
+#include <boost/graph/transpose_graph.hpp>
+#include <boost/pending/indirect_cmp.hpp>
+#include <boost/graph/connected_components.hpp> // 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)
+ {
+ function_requires< 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 (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;
+ tie(i, iend) = vertices(G_T);
+ 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
+
+#endif // BOOST_GRAPH_STRONG_COMPONENTS_HPP