default-constructor2.cpp 1.6 KB

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  1. //=======================================================================
  2. // Copyright 2001 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. #include <boost/config.hpp>
  9. #include <fstream>
  10. #include <boost/graph/adjacency_list.hpp>
  11. using namespace boost;
  12. template < typename Graph > void
  13. read_graph_file(std::istream & in, Graph & g)
  14. {
  15. typedef typename graph_traits < Graph >::vertex_descriptor Vertex;
  16. typedef typename graph_traits < Graph >::vertices_size_type size_type;
  17. size_type n_vertices;
  18. in >> n_vertices; // read in number of vertices
  19. std::vector < Vertex > vertex_set(n_vertices);
  20. for (size_type i = 0; i < n_vertices; ++i)
  21. vertex_set[i] = add_vertex(g);
  22. size_type u, v;
  23. while (in >> u)
  24. if (in >> v)
  25. add_edge(vertex_set[u], vertex_set[v], g);
  26. else
  27. break;
  28. }
  29. int
  30. main(int argc, const char** argv)
  31. {
  32. typedef adjacency_list < listS, // Store out-edges of each vertex in a std::list
  33. vecS, // Store vertex set in a std::vector
  34. directedS // The graph is directed
  35. > graph_type;
  36. graph_type g; // use default constructor to create empty graph
  37. std::ifstream file_in(argc >= 2 ? argv[1] : "makefile-dependencies.dat");
  38. read_graph_file(file_in, g);
  39. assert(num_vertices(g) == 15);
  40. assert(num_edges(g) == 19);
  41. return 0;
  42. }