1 //=======================================================================
2 // Copyright 2002 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
9 #include <string>
10 #include <boost/graph/adjacency_list.hpp>
11 #include <boost/graph/undirected_dfs.hpp>
12 #include <boost/cstdlib.hpp>
13 #include <iostream>
14
15 /*
16 Example graph from Tarjei Knapstad.
17
18 H15
19 |
20 H8 C2
21 \ / \
22 H9-C0-C1 C3-O7-H14
23 / | |
24 H10 C6 C4
25 / \ / \
26 H11 C5 H13
27 |
28 H12
29 */
30
31 std::string name[] = { "C0", "C1", "C2", "C3", "C4", "C5", "C6", "O7", "H8",
32 "H9", "H10", "H11", "H12", "H13", "H14", "H15" };
33
34 struct detect_loops : public boost::dfs_visitor<>
35 {
back_edgedetect_loops36 template < class Edge, class Graph > void back_edge(Edge e, const Graph& g)
37 {
38 std::cout << name[source(e, g)] << " -- " << name[target(e, g)] << "\n";
39 }
40 };
41
main(int,char * [])42 int main(int, char*[])
43 {
44 using namespace boost;
45 typedef adjacency_list< vecS, vecS, undirectedS, no_property,
46 property< edge_color_t, default_color_type > >
47 graph_t;
48 typedef graph_traits< graph_t >::vertex_descriptor vertex_t;
49
50 const std::size_t N = sizeof(name) / sizeof(std::string);
51 graph_t g(N);
52
53 add_edge(0, 1, g);
54 add_edge(0, 8, g);
55 add_edge(0, 9, g);
56 add_edge(0, 10, g);
57 add_edge(1, 2, g);
58 add_edge(1, 6, g);
59 add_edge(2, 15, g);
60 add_edge(2, 3, g);
61 add_edge(3, 7, g);
62 add_edge(3, 4, g);
63 add_edge(4, 13, g);
64 add_edge(4, 5, g);
65 add_edge(5, 12, g);
66 add_edge(5, 6, g);
67 add_edge(6, 11, g);
68 add_edge(7, 14, g);
69
70 std::cout << "back edges:\n";
71 detect_loops vis;
72 undirected_dfs(g,
73 root_vertex(vertex_t(0))
74 .visitor(vis)
75 .edge_color_map(get(edge_color, g)));
76 std::cout << std::endl;
77
78 return boost::exit_success;
79 }
80