epoc32/include/stdapis/boost/graph/strong_components.hpp
branchSymbian2
changeset 2 2fe1408b6811
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/epoc32/include/stdapis/boost/graph/strong_components.hpp	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -0,0 +1,334 @@
     1.4 +//
     1.5 +//=======================================================================
     1.6 +// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
     1.7 +// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
     1.8 +//
     1.9 +// Distributed under the Boost Software License, Version 1.0. (See
    1.10 +// accompanying file LICENSE_1_0.txt or copy at
    1.11 +// http://www.boost.org/LICENSE_1_0.txt)
    1.12 +//=======================================================================
    1.13 +//
    1.14 +
    1.15 +#ifndef BOOST_GRAPH_STRONG_COMPONENTS_HPP
    1.16 +#define BOOST_GRAPH_STRONG_COMPONENTS_HPP
    1.17 +
    1.18 +#include <stack>
    1.19 +#include <boost/config.hpp>
    1.20 +#include <boost/graph/depth_first_search.hpp>
    1.21 +#include <boost/type_traits/conversion_traits.hpp>
    1.22 +#include <boost/static_assert.hpp>
    1.23 +
    1.24 +namespace boost {
    1.25 +
    1.26 +  //==========================================================================
    1.27 +  // This is Tarjan's algorithm for strongly connected components
    1.28 +  // from his paper "Depth first search and linear graph algorithms".
    1.29 +  // It calculates the components in a single application of DFS.
    1.30 +  // We implement the algorithm as a dfs-visitor.
    1.31 +
    1.32 +  namespace detail {
    1.33 +    
    1.34 +    template <typename ComponentMap, typename RootMap, typename DiscoverTime,
    1.35 +              typename Stack>
    1.36 +    class tarjan_scc_visitor : public dfs_visitor<> 
    1.37 +    {
    1.38 +      typedef typename property_traits<ComponentMap>::value_type comp_type;
    1.39 +      typedef typename property_traits<DiscoverTime>::value_type time_type;
    1.40 +    public:
    1.41 +      tarjan_scc_visitor(ComponentMap comp_map, RootMap r, DiscoverTime d, 
    1.42 +                         comp_type& c_, Stack& s_)
    1.43 +        : c(c_), comp(comp_map), root(r), discover_time(d),
    1.44 +          dfs_time(time_type()), s(s_) { }
    1.45 +
    1.46 +      template <typename Graph>
    1.47 +      void discover_vertex(typename graph_traits<Graph>::vertex_descriptor v,
    1.48 +                           const Graph&) {
    1.49 +        put(root, v, v);
    1.50 +        put(comp, v, (std::numeric_limits<comp_type>::max)());
    1.51 +        put(discover_time, v, dfs_time++);
    1.52 +        s.push(v);
    1.53 +      }
    1.54 +      template <typename Graph>
    1.55 +      void finish_vertex(typename graph_traits<Graph>::vertex_descriptor v,
    1.56 +                         const Graph& g) {
    1.57 +        typename graph_traits<Graph>::vertex_descriptor w;
    1.58 +        typename graph_traits<Graph>::out_edge_iterator ei, ei_end;
    1.59 +        for (tie(ei, ei_end) = out_edges(v, g); ei != ei_end; ++ei) {
    1.60 +          w = target(*ei, g);
    1.61 +          if (get(comp, w) == (std::numeric_limits<comp_type>::max)())
    1.62 +            put(root, v, this->min_discover_time(get(root,v), get(root,w)));
    1.63 +        }
    1.64 +        if (get(root, v) == v) {
    1.65 +          do {
    1.66 +            w = s.top(); s.pop();
    1.67 +            put(comp, w, c);
    1.68 +          } while (w != v);
    1.69 +          ++c;
    1.70 +        }
    1.71 +      }
    1.72 +    private:
    1.73 +      template <typename Vertex>
    1.74 +      Vertex min_discover_time(Vertex u, Vertex v) {
    1.75 +        return get(discover_time, u) < get(discover_time,v) ? u : v;
    1.76 +      }
    1.77 +
    1.78 +      comp_type& c;
    1.79 +      ComponentMap comp;
    1.80 +      RootMap root;
    1.81 +      DiscoverTime discover_time;
    1.82 +      time_type dfs_time;
    1.83 +      Stack& s;
    1.84 +    };
    1.85 +    
    1.86 +    template <class Graph, class ComponentMap, class RootMap,
    1.87 +              class DiscoverTime, class P, class T, class R>
    1.88 +    typename property_traits<ComponentMap>::value_type
    1.89 +    strong_components_impl
    1.90 +      (const Graph& g,    // Input
    1.91 +       ComponentMap comp, // Output
    1.92 +       // Internal record keeping
    1.93 +       RootMap root, 
    1.94 +       DiscoverTime discover_time,
    1.95 +       const bgl_named_params<P, T, R>& params)
    1.96 +    {
    1.97 +      typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
    1.98 +      function_requires< ReadWritePropertyMapConcept<ComponentMap, Vertex> >();
    1.99 +      function_requires< ReadWritePropertyMapConcept<RootMap, Vertex> >();
   1.100 +      typedef typename property_traits<RootMap>::value_type RootV;
   1.101 +      function_requires< ConvertibleConcept<RootV, Vertex> >();
   1.102 +      function_requires< ReadWritePropertyMapConcept<DiscoverTime, Vertex> >();
   1.103 +
   1.104 +      typename property_traits<ComponentMap>::value_type total = 0;
   1.105 +
   1.106 +      std::stack<Vertex> s;
   1.107 +      detail::tarjan_scc_visitor<ComponentMap, RootMap, DiscoverTime, 
   1.108 +        std::stack<Vertex> > 
   1.109 +        vis(comp, root, discover_time, total, s);
   1.110 +      depth_first_search(g, params.visitor(vis));
   1.111 +      return total;
   1.112 +    }
   1.113 +
   1.114 +    //-------------------------------------------------------------------------
   1.115 +    // The dispatch functions handle the defaults for the rank and discover
   1.116 +    // time property maps.
   1.117 +    // dispatch with class specialization to avoid VC++ bug
   1.118 +
   1.119 +    template <class DiscoverTimeMap>
   1.120 +    struct strong_comp_dispatch2 {
   1.121 +      template <class Graph, class ComponentMap, class RootMap, class P, class T, class R>
   1.122 +      inline static typename property_traits<ComponentMap>::value_type
   1.123 +      apply(const Graph& g,
   1.124 +            ComponentMap comp,
   1.125 +            RootMap r_map,
   1.126 +            const bgl_named_params<P, T, R>& params,
   1.127 +            DiscoverTimeMap time_map)
   1.128 +      {
   1.129 +        return strong_components_impl(g, comp, r_map, time_map, params);
   1.130 +      }
   1.131 +    };
   1.132 +
   1.133 +
   1.134 +    template <>
   1.135 +    struct strong_comp_dispatch2<detail::error_property_not_found> {
   1.136 +      template <class Graph, class ComponentMap, class RootMap,
   1.137 +                class P, class T, class R>
   1.138 +      inline static typename property_traits<ComponentMap>::value_type
   1.139 +      apply(const Graph& g,
   1.140 +            ComponentMap comp,
   1.141 +            RootMap r_map,
   1.142 +            const bgl_named_params<P, T, R>& params,
   1.143 +            detail::error_property_not_found)
   1.144 +      {
   1.145 +        typedef typename graph_traits<Graph>::vertices_size_type size_type;
   1.146 +        size_type       n = num_vertices(g) > 0 ? num_vertices(g) : 1;
   1.147 +        std::vector<size_type> time_vec(n);
   1.148 +        return strong_components_impl
   1.149 +          (g, comp, r_map,
   1.150 +           make_iterator_property_map(time_vec.begin(), choose_const_pmap
   1.151 +                                      (get_param(params, vertex_index),
   1.152 +                                       g, vertex_index), time_vec[0]),
   1.153 +           params);
   1.154 +      }
   1.155 +    };
   1.156 +
   1.157 +    template <class Graph, class ComponentMap, class RootMap,
   1.158 +              class P, class T, class R, class DiscoverTimeMap>
   1.159 +    inline typename property_traits<ComponentMap>::value_type
   1.160 +    scc_helper2(const Graph& g,
   1.161 +                ComponentMap comp,
   1.162 +                RootMap r_map,
   1.163 +                const bgl_named_params<P, T, R>& params,
   1.164 +                DiscoverTimeMap time_map)
   1.165 +    {
   1.166 +      return strong_comp_dispatch2<DiscoverTimeMap>::apply(g, comp, r_map, params, time_map);
   1.167 +    }
   1.168 +
   1.169 +    template <class RootMap>
   1.170 +    struct strong_comp_dispatch1 {
   1.171 +
   1.172 +      template <class Graph, class ComponentMap, class P, class T, class R>
   1.173 +      inline static typename property_traits<ComponentMap>::value_type
   1.174 +      apply(const Graph& g,
   1.175 +            ComponentMap comp,
   1.176 +            const bgl_named_params<P, T, R>& params,
   1.177 +            RootMap r_map)
   1.178 +      {
   1.179 +        return scc_helper2(g, comp, r_map, params, get_param(params, vertex_discover_time));
   1.180 +      }
   1.181 +    };
   1.182 +    template <>
   1.183 +    struct strong_comp_dispatch1<detail::error_property_not_found> {
   1.184 +
   1.185 +      template <class Graph, class ComponentMap, 
   1.186 +                class P, class T, class R>
   1.187 +      inline static typename property_traits<ComponentMap>::value_type
   1.188 +      apply(const Graph& g,
   1.189 +            ComponentMap comp,
   1.190 +            const bgl_named_params<P, T, R>& params,
   1.191 +            detail::error_property_not_found)
   1.192 +      {
   1.193 +        typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
   1.194 +        typename std::vector<Vertex>::size_type
   1.195 +          n = num_vertices(g) > 0 ? num_vertices(g) : 1;
   1.196 +        std::vector<Vertex> root_vec(n);
   1.197 +        return scc_helper2
   1.198 +          (g, comp, 
   1.199 +           make_iterator_property_map(root_vec.begin(), choose_const_pmap
   1.200 +                                      (get_param(params, vertex_index),
   1.201 +                                       g, vertex_index), root_vec[0]),
   1.202 +           params, 
   1.203 +           get_param(params, vertex_discover_time));
   1.204 +      }
   1.205 +    };
   1.206 +
   1.207 +    template <class Graph, class ComponentMap, class RootMap,
   1.208 +              class P, class T, class R>
   1.209 +    inline typename property_traits<ComponentMap>::value_type
   1.210 +    scc_helper1(const Graph& g,
   1.211 +               ComponentMap comp,
   1.212 +               const bgl_named_params<P, T, R>& params,
   1.213 +               RootMap r_map)
   1.214 +    {
   1.215 +      return detail::strong_comp_dispatch1<RootMap>::apply(g, comp, params,
   1.216 +                                                           r_map);
   1.217 +    }
   1.218 +
   1.219 +  } // namespace detail 
   1.220 +
   1.221 +  template <class Graph, class ComponentMap, 
   1.222 +            class P, class T, class R>
   1.223 +  inline typename property_traits<ComponentMap>::value_type
   1.224 +  strong_components(const Graph& g, ComponentMap comp,
   1.225 +                    const bgl_named_params<P, T, R>& params)
   1.226 +  {
   1.227 +    typedef typename graph_traits<Graph>::directed_category DirCat;
   1.228 +    BOOST_STATIC_ASSERT((is_convertible<DirCat*, directed_tag*>::value == true));
   1.229 +    return detail::scc_helper1(g, comp, params, 
   1.230 +                               get_param(params, vertex_root_t()));
   1.231 +  }
   1.232 +
   1.233 +  template <class Graph, class ComponentMap>
   1.234 +  inline typename property_traits<ComponentMap>::value_type
   1.235 +  strong_components(const Graph& g, ComponentMap comp)
   1.236 +  {
   1.237 +    typedef typename graph_traits<Graph>::directed_category DirCat;
   1.238 +    BOOST_STATIC_ASSERT((is_convertible<DirCat*, directed_tag*>::value == true));
   1.239 +    bgl_named_params<int, int> params(0);
   1.240 +    return strong_components(g, comp, params);
   1.241 +  }
   1.242 +
   1.243 +  template <typename Graph, typename ComponentMap, typename ComponentLists>
   1.244 +  void build_component_lists
   1.245 +    (const Graph& g,
   1.246 +     typename graph_traits<Graph>::vertices_size_type num_scc,
   1.247 +     ComponentMap component_number,
   1.248 +     ComponentLists& components)
   1.249 +  {
   1.250 +    components.resize(num_scc);
   1.251 +    typename graph_traits<Graph>::vertex_iterator vi, vi_end;
   1.252 +    for (tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
   1.253 +      components[component_number[*vi]].push_back(*vi);
   1.254 +  }
   1.255 +
   1.256 +
   1.257 +} // namespace boost
   1.258 +
   1.259 +#include <queue>
   1.260 +#include <vector>
   1.261 +#include <boost/graph/transpose_graph.hpp>
   1.262 +#include <boost/pending/indirect_cmp.hpp>
   1.263 +#include <boost/graph/connected_components.hpp> // for components_recorder
   1.264 +
   1.265 +namespace boost {
   1.266 +
   1.267 +  //==========================================================================
   1.268 +  // This is the version of strongly connected components from
   1.269 +  // "Intro. to Algorithms" by Cormen, Leiserson, Rivest, which was
   1.270 +  // adapted from "Data Structure and Algorithms" by Aho, Hopcroft,
   1.271 +  // and Ullman, who credit the algorithm to S.R. Kosaraju and M. Sharir.
   1.272 +  // The algorithm is based on computing DFS forests the graph
   1.273 +  // and its transpose.
   1.274 +
   1.275 +  // This algorithm is slower than Tarjan's by a constant factor, uses
   1.276 +  // more memory, and puts more requirements on the graph type.
   1.277 +
   1.278 +  template <class Graph, class DFSVisitor, class ComponentsMap,
   1.279 +            class DiscoverTime, class FinishTime,
   1.280 +            class ColorMap>
   1.281 +  typename property_traits<ComponentsMap>::value_type
   1.282 +  kosaraju_strong_components(Graph& G, ComponentsMap c,
   1.283 +                             FinishTime finish_time, ColorMap color)
   1.284 +  {
   1.285 +    function_requires< MutableGraphConcept<Graph> >();
   1.286 +    // ...
   1.287 +    
   1.288 +    typedef typename graph_traits<Graph>::vertex_descriptor Vertex;
   1.289 +    typedef typename property_traits<ColorMap>::value_type ColorValue;
   1.290 +    typedef color_traits<ColorValue> Color;
   1.291 +    typename property_traits<FinishTime>::value_type time = 0;
   1.292 +    depth_first_search
   1.293 +     (G, make_dfs_visitor(stamp_times(finish_time, time, on_finish_vertex())),
   1.294 +      color);
   1.295 +
   1.296 +    Graph G_T(num_vertices(G));
   1.297 +    transpose_graph(G, G_T);
   1.298 +
   1.299 +    typedef typename property_traits<ComponentsMap>::value_type count_type;
   1.300 +
   1.301 +    count_type c_count(0);
   1.302 +    detail::components_recorder<ComponentsMap>
   1.303 +      vis(c, c_count);
   1.304 +
   1.305 +    // initialize G_T
   1.306 +    typename graph_traits<Graph>::vertex_iterator ui, ui_end;
   1.307 +    for (tie(ui, ui_end) = vertices(G_T); ui != ui_end; ++ui)
   1.308 +      put(color, *ui, Color::white());
   1.309 +
   1.310 +    typedef typename property_traits<FinishTime>::value_type D;
   1.311 +    typedef indirect_cmp< FinishTime, std::less<D> > Compare;
   1.312 +
   1.313 +    Compare fl(finish_time);
   1.314 +    std::priority_queue<Vertex, std::vector<Vertex>, Compare > Q(fl);
   1.315 +
   1.316 +    typename graph_traits<Graph>::vertex_iterator i, j, iend, jend;
   1.317 +    tie(i, iend) = vertices(G_T);
   1.318 +    tie(j, jend) = vertices(G);
   1.319 +    for ( ; i != iend; ++i, ++j) {
   1.320 +      put(finish_time, *i, get(finish_time, *j));
   1.321 +       Q.push(*i);
   1.322 +    }
   1.323 +
   1.324 +    while ( !Q.empty() ) {
   1.325 +      Vertex u = Q.top();
   1.326 +      Q.pop();
   1.327 +      if  (get(color, u) == Color::white()) {
   1.328 +        depth_first_visit(G_T, u, vis, color);
   1.329 +        ++c_count; 
   1.330 +      }
   1.331 +    }
   1.332 +    return c_count;
   1.333 +  }
   1.334 +
   1.335 +} // namespace boost
   1.336 +
   1.337 +#endif // BOOST_GRAPH_STRONG_COMPONENTS_HPP