• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //=======================================================================
2 // Copyright 2007 Aaron Windsor
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 <iostream>
9 #include <boost/graph/adjacency_list.hpp>
10 #include <boost/graph/boyer_myrvold_planar_test.hpp>
11 
main(int argc,char ** argv)12 int main(int argc, char** argv)
13 {
14 
15     // This program illustrates a simple use of boyer_myrvold_planar_embedding
16     // as a simple yes/no test for planarity.
17 
18     using namespace boost;
19 
20     typedef adjacency_list< vecS, vecS, undirectedS,
21         property< vertex_index_t, int > >
22         graph;
23 
24     graph K_4(4);
25     add_edge(0, 1, K_4);
26     add_edge(0, 2, K_4);
27     add_edge(0, 3, K_4);
28     add_edge(1, 2, K_4);
29     add_edge(1, 3, K_4);
30     add_edge(2, 3, K_4);
31 
32     if (boyer_myrvold_planarity_test(K_4))
33         std::cout << "K_4 is planar." << std::endl;
34     else
35         std::cout << "ERROR! K_4 should have been recognized as planar!"
36                   << std::endl;
37 
38     graph K_5(5);
39     add_edge(0, 1, K_5);
40     add_edge(0, 2, K_5);
41     add_edge(0, 3, K_5);
42     add_edge(0, 4, K_5);
43     add_edge(1, 2, K_5);
44     add_edge(1, 3, K_5);
45     add_edge(1, 4, K_5);
46     add_edge(2, 3, K_5);
47     add_edge(2, 4, K_5);
48 
49     // We've almost created a K_5 - it's missing one edge - so it should still
50     // be planar at this point.
51 
52     if (boyer_myrvold_planarity_test(K_5))
53         std::cout << "K_5 (minus an edge) is planar." << std::endl;
54     else
55         std::cout << "ERROR! K_5 with one edge missing should"
56                   << " have been recognized as planar!" << std::endl;
57 
58     // Now add the final edge...
59     add_edge(3, 4, K_5);
60 
61     if (boyer_myrvold_planarity_test(K_5))
62         std::cout << "ERROR! K_5 was recognized as planar!" << std::endl;
63     else
64         std::cout << "K_5 is not planar." << std::endl;
65 
66     return 0;
67 }
68