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

   1 //=======================================================================
   2 // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
   3 // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
   4 //
   5 // Distributed under the Boost Software License, Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //=======================================================================
   9
  10 #include <boost/graph/dag_shortest_paths.hpp>
  11 #include <boost/graph/adjacency_list.hpp>
  12
  13 #include <iostream>
  14
  15 // Example from Introduction to Algorithms by Cormen, et all p.537.
  16
  17 // Sample output:
  18 //  r: inifinity
  19 //  s: 0
  20 //  t: 2
  21 //  u: 6
  22 //  v: 5
  23 //  x: 3
  24
  25 int main()
  26 {
  27     using namespace boost;
  28     typedef adjacency_list< vecS, vecS, directedS,
  29         property< vertex_distance_t, int >, property< edge_weight_t, int > >
  30         graph_t;
  31     graph_t g(6);
  32     enum verts
  33     {
  34         r,
  35         s,
  36         t,
  37         u,
  38         v,
  39         x
  40     };
  41     char name[] = "rstuvx";
  42     add_edge(r, s, 5, g);
  43     add_edge(r, t, 3, g);
  44     add_edge(s, t, 2, g);
  45     add_edge(s, u, 6, g);
  46     add_edge(t, u, 7, g);
  47     add_edge(t, v, 4, g);
  48     add_edge(t, x, 2, g);
  49     add_edge(u, v, -1, g);
  50     add_edge(u, x, 1, g);
  51     add_edge(v, x, -2, g);
  52
  53     property_map< graph_t, vertex_distance_t >::type d_map
  54         = get(vertex_distance, g);
  55
  56 #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300
  57     // VC++ has trouble with the named-parameter mechanism, so
  58     // we make a direct call to the underlying implementation function.
  59     std::vector< default_color_type > color(num_vertices(g));
  60     std::vector< std::size_t > pred(num_vertices(g));
  61     default_dijkstra_visitor vis;
  62     std::less< int > compare;
  63     closed_plus< int > combine;
  64     property_map< graph_t, edge_weight_t >::type w_map = get(edge_weight, g);
  65     dag_shortest_paths(g, s, d_map, w_map, &color[0], &pred[0], vis, compare,
  66         combine, (std::numeric_limits< int >::max)(), 0);
  67 #else
  68     dag_shortest_paths(g, s, distance_map(d_map));
  69 #endif
  70
  71     graph_traits< graph_t >::vertex_iterator vi, vi_end;
  72     for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
  73         if (d_map[*vi] == (std::numeric_limits< int >::max)())
  74             std::cout << name[*vi] << ": inifinity\n";
  75         else
  76             std::cout << name[*vi] << ": " << d_map[*vi] << '\n';
  77     return 0;
  78 }