boost dijkstra获得两点间的最短路

需求是只需要得到两点间的最短路，不需要求得单源对于全图的最短路，使用boost中的dijsktra_shortest_path，当得到目标点的最短路时直接throw exception。

 1 #include <boost/config.hpp>
 2 #include <iostream>
 3 
 4 #include <boost/graph/graph_traits.hpp>
 5 #include <boost/graph/adjacency_list.hpp>
 6 #include <boost/graph/dijkstra_shortest_paths.hpp>
 7 
 8 using namespace boost;
 9 
10 // define visitor for discover_vertex event
11 
12 template <class Vertex, class Tag>
13 struct target_visitor : public default_dijkstra_visitor
14 {
15  target_visitor(Vertex u) : v(u) { }
16 
17  template <class Graph>
18  void examine_vertex(Vertex u, Graph& g)
19  {
20   if( u == v ) {
21    throw(-1);
22   }
23  }
24 private:
25  Vertex v;
26 };
27 
28 template <class Vertex, class Tag>
29 target_visitor<Vertex, Tag>
30 target_visit(Vertex u, Tag) {
31  return target_visitor<Vertex, Tag>(u);
32 }
33 
34 
35 int main(int argc, char** argv)
36 {
37  typedef adjacency_list < listS, vecS, directedS,
38   no_property, property < edge_weight_t, int > > graph_t;
39  typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor;
40  typedef graph_traits < graph_t >::edge_descriptor edge_descriptor;
41  typedef std::pair<int, int> Edge;
42 
43  const int num_nodes = 5;
44  enum nodes { A, B, C, D, E };
45  char name[] = "ABCDE";
46  Edge edge_array[] =
47  {
48   Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E),
49      Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B)
50  };
51   int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 };
52  int num_arcs = sizeof(edge_array) / sizeof(Edge);
53 
54  graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes);
55  property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g);
56 
57  std::vector<vertex_descriptor> p(num_vertices(g));
58  std::vector<int> d(num_vertices(g));
59  
60  // choose source and target
61  vertex_descriptor src = vertex(A, g);
62  vertex_descriptor targ = vertex(C, g);
63 
64  
65  try {
66   dijkstra_shortest_paths(g, src,
67       predecessor_map(&p[0]).distance_map(&d[0]).visitor(target_visit(targ,
68       on_examine_vertex())));
69  }
70  catch( ... ) {
71  }
72  
73    
74  std::cout << "distances and parents:" << std::endl;
75  graph_traits < graph_t >::vertex_iterator vi, vend;
76  for (tie(vi, vend) = vertices(g); vi != vend; ++vi) {
77   std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", ";
78   std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]] << std::endl;
79  }
80  
81     system("PAUSE");
82  return EXIT_SUCCESS;
83 }