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
main()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 }
79