ceph/src/boost/boost/graph/make_connected.hpp

   1 //=======================================================================
   2 // Copyright 2007 Aaron Windsor
   3 //
   4 // Distributed under the Boost Software License, Version 1.0. (See
   5 // accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //=======================================================================
   8 #ifndef __MAKE_CONNECTED_HPP__
   9 #define __MAKE_CONNECTED_HPP__
  10
  11 #include <boost/config.hpp>
  12 #include <boost/next_prior.hpp>
  13 #include <boost/tuple/tuple.hpp> //for tie
  14 #include <boost/graph/connected_components.hpp>
  15 #include <boost/property_map/property_map.hpp>
  16 #include <vector>
  17
  18 #include <boost/graph/planar_detail/add_edge_visitors.hpp>
  19 #include <boost/graph/planar_detail/bucket_sort.hpp>
  20
  21 namespace boost
  22 {
  23
  24 template < typename Graph, typename VertexIndexMap, typename AddEdgeVisitor >
  25 void make_connected(Graph& g, VertexIndexMap vm, AddEdgeVisitor& vis)
  26 {
  27     typedef typename graph_traits< Graph >::vertex_iterator vertex_iterator_t;
  28     typedef typename graph_traits< Graph >::vertex_descriptor vertex_t;
  29     typedef typename graph_traits< Graph >::vertices_size_type v_size_t;
  30     typedef iterator_property_map< typename std::vector< v_size_t >::iterator,
  31         VertexIndexMap >
  32         vertex_to_v_size_map_t;
  33
  34     std::vector< v_size_t > component_vector(num_vertices(g));
  35     vertex_to_v_size_map_t component(component_vector.begin(), vm);
  36     std::vector< vertex_t > vertices_by_component(num_vertices(g));
  37
  38     v_size_t num_components = connected_components(g, component);
  39
  40     if (num_components < 2)
  41         return;
  42
  43     vertex_iterator_t vi, vi_end;
  44     boost::tie(vi, vi_end) = vertices(g);
  45     std::copy(vi, vi_end, vertices_by_component.begin());
  46
  47     bucket_sort(vertices_by_component.begin(), vertices_by_component.end(),
  48         component, num_components);
  49
  50     typedef typename std::vector< vertex_t >::iterator vec_of_vertices_itr_t;
  51
  52     vec_of_vertices_itr_t ci_end = vertices_by_component.end();
  53     vec_of_vertices_itr_t ci_prev = vertices_by_component.begin();
  54     if (ci_prev == ci_end)
  55         return;
  56
  57     for (vec_of_vertices_itr_t ci = boost::next(ci_prev); ci != ci_end;
  58          ci_prev = ci, ++ci)
  59     {
  60         if (component[*ci_prev] != component[*ci])
  61             vis.visit_vertex_pair(*ci_prev, *ci, g);
  62     }
  63 }
  64
  65 template < typename Graph, typename VertexIndexMap >
  66 inline void make_connected(Graph& g, VertexIndexMap vm)
  67 {
  68     default_add_edge_visitor vis;
  69     make_connected(g, vm, vis);
  70 }
  71
  72 template < typename Graph > inline void make_connected(Graph& g)
  73 {
  74     make_connected(g, get(vertex_index, g));
  75 }
  76
  77 } // namespace boost
  78
  79 #endif //__MAKE_CONNECTED_HPP__