1 // Author: Alex Lauser
2
3 // Output (Note that 'finish_edge' is never printed):
4 // The example graph:
5 // 0 --> 1 2
6 // 1 --> 2
7 // 2 --> 0
8
9 #include <boost/config.hpp>
10 #include <iostream>
11 #include <vector>
12 #include <boost/graph/adjacency_list.hpp>
13 #include <boost/graph/graph_utility.hpp>
14
15 template < typename graph_t > struct TalkativeVisitor : boost::dfs_visitor<>
16 {
17 typedef typename boost::graph_traits< graph_t >::vertex_descriptor
18 vertex_descriptor;
19 typedef typename boost::graph_traits< graph_t >::edge_descriptor
20 edge_descriptor;
21
22 // // Commented out to avoid clutter of the output.
23 // void discover_vertex(vertex_descriptor u, const graph_t&) { // check!
24 // std::cout << "discover_vertex: " << u << std::endl;
25 // }
26 // void finish_vertex(vertex_descriptor u, const graph_t&) { // check!
27 // std::cout << "finish_vertex: " << u << std::endl;
28 // }
29 // void initialize_vertex(vertex_descriptor u, const graph_t&) { // check!
30 // std::cout << "initialize_vertex: " << u << std::endl;
31 // }
32 // void start_vertex(vertex_descriptor u, const graph_t&) { // check!
33 // std::cout << "start_vertex: " << u << std::endl;
34 // }
35 // void examine_edge(edge_descriptor u, const graph_t&) { // check!
36 // std::cout << "examine_edge: " << u << std::endl;
37 // }
38 // void tree_edge(edge_descriptor u, const graph_t&) { // check!
39 // std::cout << "tree_edge: " << u << std::endl;
40 // }
41 // void back_edge(edge_descriptor u, const graph_t&) { // check!
42 // std::cout << "back_edge: " << u << std::endl;
43 // }
44 // void forward_or_cross_edge(edge_descriptor u, const graph_t&) { // check!
45 // std::cout << "forward_or_cross_edge: " << u << std::endl;
46 // }
finish_edgeTalkativeVisitor47 void finish_edge(edge_descriptor u, const graph_t&)
48 { // uncalled!
49 std::cout << "finish_edge: " << u << std::endl;
50 }
51 };
52
53 template < typename t >
operator <<(std::ostream & os,const std::pair<t,t> & x)54 std::ostream& operator<<(std::ostream& os, const std::pair< t, t >& x)
55 {
56 return os << "(" << x.first << ", " << x.second << ")";
57 }
58
main(int,char * [])59 int main(int, char*[])
60 {
61 using namespace boost;
62
63 typedef adjacency_list< vecS, vecS, directedS > Graph;
64 Graph G;
65
66 typedef graph_traits<
67 adjacency_list< vecS, vecS, directedS > >::vertex_descriptor Vertex;
68 Vertex a = add_vertex(G);
69 Vertex b = add_vertex(G);
70 Vertex c = add_vertex(G);
71
72 add_edge(a, b, G);
73 add_edge(b, c, G);
74 add_edge(c, a, G);
75 add_edge(a, c, G);
76
77 std::cout << "The example graph:" << std::endl;
78 print_graph(G);
79
80 std::vector< default_color_type > color(num_vertices(G));
81 depth_first_search(G, visitor(TalkativeVisitor< Graph >()));
82
83 return 0;
84 }
85