Ticket #3257: mstree_prim.cpp

#include <boost/config.hpp>
#include <iostream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/prim_minimum_spanning_tree.hpp>

int
main()
{
  using namespace boost;
  typedef adjacency_list < vecS, vecS, undirectedS,
    property<vertex_distance_t, int>, property < edge_weight_t, int > > Graph;
  typedef std::pair < int, int >E;
  const int num_nodes = 6;

#if SPECIFY_ONCE
  E edges_l[] = {          E(0, 1), E(0, 2), E(0, 3), E(0, 4), E(0, 5),
                                    E(1, 2), E(1, 3), E(1, 4), E(1, 5),
                                             E(2, 3), E(2, 4), E(2, 5),
                                                      E(3, 4), E(3, 5),
                                                               E(4, 5),
                };
  int weights[] = {    6,  7, 26,  9,  2,
                           1, 26, 10,  5,
                              27, 11,  6,
                                  17, 24,
                                       7,
                };
#else
  E edges_l[] = {          E(0, 1), E(0, 2), E(0, 3), E(0, 4), E(0, 5),
                  E(1, 0),          E(1, 2), E(1, 3), E(1, 4), E(1, 5),
                  E(2, 0), E(2, 1),          E(2, 3), E(2, 4), E(2, 5),
                  E(3, 0), E(3, 1), E(3, 2),          E(3, 4), E(3, 5),
                  E(4, 0), E(4, 1), E(4, 2), E(4, 3),          E(4, 5),
                  E(5, 0), E(5, 1), E(5, 2), E(5, 3), E(5, 4)
                };
  int weights[] = {    6,  7, 26,  9,  2,
                   6,      1, 26, 10,  5,
                   7,  1,     27, 11,  6,
                  26, 26, 27,     17, 24,
                   9, 10, 11, 17,      7,
                   2,  5,  6, 24,  7
                };
#endif

  Graph g(edges_l, edges_l + sizeof(edges_l) / sizeof(E), weights, num_nodes);
  property_map<Graph, edge_weight_t>::type weightmap = get(edge_weight, g);

  std::vector < graph_traits < Graph >::vertex_descriptor >
    p(num_vertices(g));

#if DEBUG
    typedef graph_traits<Graph>::edge_iterator   edge_iterator;
    edge_iterator ei, e_end;

    std::cout << " edge info: " << std::endl;
    for ( tie(ei, e_end) = edges(g); ei != e_end; ++ei )
    {
         std::cout << " from " << source(*ei, g);
         std::cout << " to " << target(*ei, g);
         std::cout << " weight " << weightmap[*ei];
         std::cout << std::endl;
     }
     std::cout << std::endl;
#endif

  prim_minimum_spanning_tree(g, &p[0]);

  for (std::size_t i = 0; i != p.size(); ++i)
    if (p[i] != i)
      std::cout << "parent[" << i << "] = " << p[i] << std::endl;
    else
      std::cout << "parent[" << i << "] = no parent" << std::endl;

  return EXIT_SUCCESS;
}