ceph/src/boost/libs/graph/example/cuthill_mckee_ordering.cpp

   1 //=======================================================================
   2 // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
   3 // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
   4 //          Doug Gregor, D. Kevin McGrath
   5 //
   6 // Distributed under the Boost Software License, Version 1.0.
   7 // (See accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9 //=======================================================================
  10
  11 #include <boost/config.hpp>
  12 #include <vector>
  13 #include <iostream>
  14 #include <boost/graph/adjacency_list.hpp>
  15 #include <boost/graph/cuthill_mckee_ordering.hpp>
  16 #include <boost/graph/properties.hpp>
  17 #include <boost/graph/bandwidth.hpp>
  18
  19 /*
  20   Sample Output
  21   original bandwidth: 8
  22   Reverse Cuthill-McKee ordering starting at: 6
  23     8 3 0 9 2 5 1 4 7 6
  24     bandwidth: 4
  25   Reverse Cuthill-McKee ordering starting at: 0
  26     9 1 4 6 7 2 8 5 3 0
  27     bandwidth: 4
  28   Reverse Cuthill-McKee ordering:
  29     0 8 5 7 3 6 4 2 1 9
  30     bandwidth: 4
  31  */
  32 int main(int , char* [])
  33 {
  34   using namespace boost;
  35   using namespace std;
  36   typedef adjacency_list<vecS, vecS, undirectedS,
  37      property<vertex_color_t, default_color_type,
  38        property<vertex_degree_t,int> > > Graph;
  39   typedef graph_traits<Graph>::vertex_descriptor Vertex;
  40   typedef graph_traits<Graph>::vertices_size_type size_type;
  41
  42   typedef std::pair<std::size_t, std::size_t> Pair;
  43   Pair edges[14] = { Pair(0,3), //a-d
  44                      Pair(0,5),  //a-f
  45                      Pair(1,2),  //b-c
  46                      Pair(1,4),  //b-e
  47                      Pair(1,6),  //b-g
  48                      Pair(1,9),  //b-j
  49                      Pair(2,3),  //c-d
  50                      Pair(2,4),  //c-e
  51                      Pair(3,5),  //d-f
  52                      Pair(3,8),  //d-i
  53                      Pair(4,6),  //e-g
  54                      Pair(5,6),  //f-g
  55                      Pair(5,7),  //f-h
  56                      Pair(6,7) }; //g-h
  57
  58   Graph G(10);
  59   for (int i = 0; i < 14; ++i)
  60     add_edge(edges[i].first, edges[i].second, G);
  61
  62   graph_traits<Graph>::vertex_iterator ui, ui_end;
  63
  64   property_map<Graph,vertex_degree_t>::type deg = get(vertex_degree, G);
  65   for (boost::tie(ui, ui_end) = vertices(G); ui != ui_end; ++ui)
  66     deg[*ui] = degree(*ui, G);
  67
  68   property_map<Graph, vertex_index_t>::type
  69     index_map = get(vertex_index, G);
  70
  71   std::cout << "original bandwidth: " << bandwidth(G) << std::endl;
  72
  73   std::vector<Vertex> inv_perm(num_vertices(G));
  74   std::vector<size_type> perm(num_vertices(G));
  75   {
  76     Vertex s = vertex(6, G);
  77     //reverse cuthill_mckee_ordering
  78     cuthill_mckee_ordering(G, s, inv_perm.rbegin(), get(vertex_color, G),
  79                            get(vertex_degree, G));
  80     cout << "Reverse Cuthill-McKee ordering starting at: " << s << endl;
  81     cout << "  ";
  82     for (std::vector<Vertex>::const_iterator i = inv_perm.begin();
  83          i != inv_perm.end(); ++i)
  84       cout << index_map[*i] << " ";
  85     cout << endl;
  86
  87     for (size_type c = 0; c != inv_perm.size(); ++c)
  88       perm[index_map[inv_perm[c]]] = c;
  89     std::cout << "  bandwidth: "
  90               << bandwidth(G, make_iterator_property_map(&perm[0], index_map, perm[0]))
  91               << std::endl;
  92   }
  93   {
  94     Vertex s = vertex(0, G);
  95     //reverse cuthill_mckee_ordering
  96     cuthill_mckee_ordering(G, s, inv_perm.rbegin(), get(vertex_color, G),
  97                            get(vertex_degree, G));
  98     cout << "Reverse Cuthill-McKee ordering starting at: " << s << endl;
  99     cout << "  ";
 100     for (std::vector<Vertex>::const_iterator i=inv_perm.begin();
 101        i != inv_perm.end(); ++i)
 102       cout << index_map[*i] << " ";
 103     cout << endl;
 104
 105     for (size_type c = 0; c != inv_perm.size(); ++c)
 106       perm[index_map[inv_perm[c]]] = c;
 107     std::cout << "  bandwidth: "
 108               << bandwidth(G, make_iterator_property_map(&perm[0], index_map, perm[0]))
 109               << std::endl;
 110   }
 111
 112   {
 113     //reverse cuthill_mckee_ordering
 114     cuthill_mckee_ordering(G, inv_perm.rbegin(), get(vertex_color, G),
 115                            make_degree_map(G));
 116
 117     cout << "Reverse Cuthill-McKee ordering:" << endl;
 118     cout << "  ";
 119     for (std::vector<Vertex>::const_iterator i=inv_perm.begin();
 120        i != inv_perm.end(); ++i)
 121       cout << index_map[*i] << " ";
 122     cout << endl;
 123
 124     for (size_type c = 0; c != inv_perm.size(); ++c)
 125       perm[index_map[inv_perm[c]]] = c;
 126     std::cout << "  bandwidth: "
 127               << bandwidth(G, make_iterator_property_map(&perm[0], index_map, perm[0]))
 128               << std::endl;
 129   }
 130   return 0;
 131 }