1 //=======================================================================
2 // Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee,
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 #include <boost/config.hpp>
9 #include <iostream>
10 #include <fstream>
11
12 #include <boost/graph/graph_traits.hpp>
13 #include <boost/graph/adjacency_list.hpp>
14 #include <boost/graph/dijkstra_shortest_paths.hpp>
15
16 using namespace boost;
17
main(int,char * [])18 int main(int, char*[])
19 {
20 typedef adjacency_list_traits< listS, listS, directedS >::vertex_descriptor
21 vertex_descriptor;
22 typedef adjacency_list< listS, listS, directedS,
23 property< vertex_index_t, int,
24 property< vertex_name_t, char,
25 property< vertex_distance_t, int,
26 property< vertex_predecessor_t, vertex_descriptor > > > >,
27 property< edge_weight_t, int > >
28 graph_t;
29 typedef std::pair< int, int > Edge;
30
31 const int num_nodes = 5;
32 enum nodes
33 {
34 A,
35 B,
36 C,
37 D,
38 E
39 };
40 Edge edge_array[] = { Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E),
41 Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B) };
42 int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 };
43 int num_arcs = sizeof(edge_array) / sizeof(Edge);
44 graph_traits< graph_t >::vertex_iterator i, iend;
45
46 graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes);
47 property_map< graph_t, edge_weight_t >::type weightmap
48 = get(edge_weight, g);
49
50 // Manually intialize the vertex index and name maps
51 property_map< graph_t, vertex_index_t >::type indexmap
52 = get(vertex_index, g);
53 property_map< graph_t, vertex_name_t >::type name = get(vertex_name, g);
54 int c = 0;
55 for (boost::tie(i, iend) = vertices(g); i != iend; ++i, ++c)
56 {
57 indexmap[*i] = c;
58 name[*i] = 'A' + c;
59 }
60
61 vertex_descriptor s = vertex(A, g);
62
63 property_map< graph_t, vertex_distance_t >::type d
64 = get(vertex_distance, g);
65 property_map< graph_t, vertex_predecessor_t >::type p
66 = get(vertex_predecessor, g);
67 dijkstra_shortest_paths(g, s, predecessor_map(p).distance_map(d));
68
69 std::cout << "distances and parents:" << std::endl;
70 graph_traits< graph_t >::vertex_iterator vi, vend;
71 for (boost::tie(vi, vend) = vertices(g); vi != vend; ++vi)
72 {
73 std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", ";
74 std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]]
75 << std::endl;
76 }
77 std::cout << std::endl;
78
79 std::ofstream dot_file("figs/dijkstra-eg.dot");
80 dot_file << "digraph D {\n"
81 << " rankdir=LR\n"
82 << " size=\"4,3\"\n"
83 << " ratio=\"fill\"\n"
84 << " edge[style=\"bold\"]\n"
85 << " node[shape=\"circle\"]\n";
86
87 graph_traits< graph_t >::edge_iterator ei, ei_end;
88 for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei)
89 {
90 graph_traits< graph_t >::edge_descriptor e = *ei;
91 graph_traits< graph_t >::vertex_descriptor u = source(e, g),
92 v = target(e, g);
93 dot_file << name[u] << " -> " << name[v] << "[label=\""
94 << get(weightmap, e) << "\"";
95 if (p[v] == u)
96 dot_file << ", color=\"black\"";
97 else
98 dot_file << ", color=\"grey\"";
99 dot_file << "]";
100 }
101 dot_file << "}";
102 return EXIT_SUCCESS;
103 }
104