1 // (C) Copyright 2007-2009 Andrew Sutton
2 //
3 // Use, modification and distribution are subject to the
4 // Boost Software License, Version 1.0 (See accompanying file
5 // LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
6
7 #include <iostream>
8
9 #include <boost/graph/graph_utility.hpp>
10 #include <boost/graph/undirected_graph.hpp>
11 #include <boost/graph/directed_graph.hpp>
12 #include <boost/graph/tiernan_all_cycles.hpp>
13 #include <boost/graph/erdos_renyi_generator.hpp>
14
15 #include <boost/random/linear_congruential.hpp>
16
17 using namespace std;
18 using namespace boost;
19
20 struct cycle_validator
21 {
cycle_validatorcycle_validator22 cycle_validator(size_t& c) : cycles(c) {}
23
24 template < typename Path, typename Graph >
cyclecycle_validator25 void cycle(const Path& p, const Graph& g)
26 {
27 ++cycles;
28 // Check to make sure that each of the vertices in the path
29 // is truly connected and that the back is connected to the
30 // front - it's not validating that we find all paths, just
31 // that the paths are valid.
32 typename Path::const_iterator i, j, last = prior(p.end());
33 for (i = p.begin(); i != last; ++i)
34 {
35 j = boost::next(i);
36 BOOST_ASSERT(edge(*i, *j, g).second);
37 }
38 BOOST_ASSERT(edge(p.back(), p.front(), g).second);
39 }
40
41 size_t& cycles;
42 };
43
test()44 template < typename Graph > void test()
45 {
46 typedef erdos_renyi_iterator< boost::minstd_rand, Graph > er;
47
48 // Generate random graphs with 15 vertices and 15% probability
49 // of edge connection.
50 static const size_t N = 20;
51 static const double P = 0.1;
52 boost::minstd_rand rng;
53
54 Graph g(er(rng, N, P), er(), N);
55 renumber_indices(g);
56 print_edges(g, get(vertex_index, g));
57
58 size_t cycles = 0;
59 cycle_validator vis(cycles);
60 tiernan_all_cycles(g, vis);
61 cout << "# cycles: " << vis.cycles << "\n";
62 }
63
main(int,char * [])64 int main(int, char*[])
65 {
66 typedef undirected_graph<> Graph;
67 typedef directed_graph<> DiGraph;
68
69 std::cout << "*** undirected ***\n";
70 test< Graph >();
71
72 std::cout << "*** directed ***\n";
73 test< DiGraph >();
74 }
75