1 // (C) Copyright 2013 Louis Dionne
2 //
3 // Modified from `tiernan_all_cycles.cpp`.
4 //
5 // Use, modification and distribution are subject to the
6 // Boost Software License, Version 1.0 (See accompanying file
7 // LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
8
9 #ifndef BOOST_GRAPH_TEST_CYCLE_TEST_HPP
10 #define BOOST_GRAPH_TEST_CYCLE_TEST_HPP
11
12 #include <boost/assert.hpp>
13 #include <boost/graph/directed_graph.hpp>
14 #include <boost/graph/erdos_renyi_generator.hpp>
15 #include <boost/graph/graph_traits.hpp>
16 #include <boost/graph/graph_utility.hpp>
17 #include <boost/graph/undirected_graph.hpp>
18 #include <boost/next_prior.hpp>
19 #include <boost/random/linear_congruential.hpp>
20 #include <cstddef>
21 #include <iostream>
22
23 namespace cycle_test_detail
24 {
25 using namespace boost;
26
27 struct cycle_validator
28 {
cycle_validatorcycle_test_detail::cycle_validator29 explicit cycle_validator(std::size_t& number_of_cycles)
30 : cycles(number_of_cycles)
31 {
32 }
33
34 template < typename Path, typename Graph >
cyclecycle_test_detail::cycle_validator35 void cycle(Path const& p, Graph const& g)
36 {
37 ++cycles;
38 // Check to make sure that each of the vertices in the path
39 // is truly connected and that the back is connected to the
40 // front - it's not validating that we find all paths, just
41 // that the paths are valid.
42 typename Path::const_iterator i, j, last = prior(p.end());
43 for (i = p.begin(); i != last; ++i)
44 {
45 j = boost::next(i);
46 BOOST_ASSERT(edge(*i, *j, g).second);
47 }
48 BOOST_ASSERT(edge(p.back(), p.front(), g).second);
49 }
50
51 std::size_t& cycles;
52 };
53
54 template < typename Graph, typename Algorithm >
test_one(Algorithm algorithm)55 void test_one(Algorithm algorithm)
56 {
57 typedef erdos_renyi_iterator< minstd_rand, Graph > er;
58
59 // Generate random graphs with 15 vertices and 15% probability
60 // of edge connection.
61 static std::size_t const N = 20;
62 static double const P = 0.1;
63 minstd_rand rng;
64
65 Graph g(er(rng, N, P), er(), N);
66 renumber_indices(g);
67 print_edges(g, get(vertex_index, g));
68
69 std::size_t cycles = 0;
70 cycle_validator vis(cycles);
71 algorithm(g, vis);
72 std::cout << "# cycles: " << vis.cycles << "\n";
73 }
74 } // end namespace cycle_test_detail
75
cycle_test(Algorithm const & algorithm)76 template < typename Algorithm > void cycle_test(Algorithm const& algorithm)
77 {
78 std::cout << "*** undirected ***\n";
79 cycle_test_detail::test_one< boost::undirected_graph<> >(algorithm);
80
81 std::cout << "*** directed ***\n";
82 cycle_test_detail::test_one< boost::directed_graph<> >(algorithm);
83 }
84
85 #endif // !BOOST_GRAPH_TEST_CYCLE_TEST_HPP
86