| //======================================================================= |
| // Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee, |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See |
| // accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| //======================================================================= |
| #include <boost/config.hpp> |
| #include <iostream> |
| #include <fstream> |
| |
| #include <boost/graph/graph_traits.hpp> |
| #include <boost/graph/adjacency_list.hpp> |
| #include <boost/graph/dijkstra_shortest_paths.hpp> |
| |
| using namespace boost; |
| |
| int |
| main(int, char *[]) |
| { |
| typedef adjacency_list < listS, vecS, directedS, |
| no_property, property < edge_weight_t, int > > graph_t; |
| typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor; |
| typedef graph_traits < graph_t >::edge_descriptor edge_descriptor; |
| typedef std::pair<int, int> Edge; |
| |
| const int num_nodes = 5; |
| enum nodes { A, B, C, D, E }; |
| char name[] = "ABCDE"; |
| Edge edge_array[] = { Edge(A, C), Edge(B, B), Edge(B, D), Edge(B, E), |
| Edge(C, B), Edge(C, D), Edge(D, E), Edge(E, A), Edge(E, B) |
| }; |
| int weights[] = { 1, 2, 1, 2, 7, 3, 1, 1, 1 }; |
| int num_arcs = sizeof(edge_array) / sizeof(Edge); |
| #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 |
| graph_t g(num_nodes); |
| property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g); |
| for (std::size_t j = 0; j < num_arcs; ++j) { |
| edge_descriptor e; bool inserted; |
| boost::tie(e, inserted) = add_edge(edge_array[j].first, edge_array[j].second, g); |
| weightmap[e] = weights[j]; |
| } |
| #else |
| graph_t g(edge_array, edge_array + num_arcs, weights, num_nodes); |
| property_map<graph_t, edge_weight_t>::type weightmap = get(edge_weight, g); |
| #endif |
| std::vector<vertex_descriptor> p(num_vertices(g)); |
| std::vector<int> d(num_vertices(g)); |
| vertex_descriptor s = vertex(A, g); |
| |
| #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 |
| // VC++ has trouble with the named parameters mechanism |
| property_map<graph_t, vertex_index_t>::type indexmap = get(vertex_index, g); |
| dijkstra_shortest_paths(g, s, &p[0], &d[0], weightmap, indexmap, |
| std::less<int>(), closed_plus<int>(), |
| (std::numeric_limits<int>::max)(), 0, |
| default_dijkstra_visitor()); |
| #else |
| dijkstra_shortest_paths(g, s, predecessor_map(&p[0]).distance_map(&d[0])); |
| #endif |
| |
| std::cout << "distances and parents:" << std::endl; |
| graph_traits < graph_t >::vertex_iterator vi, vend; |
| for (boost::tie(vi, vend) = vertices(g); vi != vend; ++vi) { |
| std::cout << "distance(" << name[*vi] << ") = " << d[*vi] << ", "; |
| std::cout << "parent(" << name[*vi] << ") = " << name[p[*vi]] << std:: |
| endl; |
| } |
| std::cout << std::endl; |
| |
| std::ofstream dot_file("figs/dijkstra-eg.dot"); |
| |
| dot_file << "digraph D {\n" |
| << " rankdir=LR\n" |
| << " size=\"4,3\"\n" |
| << " ratio=\"fill\"\n" |
| << " edge[style=\"bold\"]\n" << " node[shape=\"circle\"]\n"; |
| |
| graph_traits < graph_t >::edge_iterator ei, ei_end; |
| for (boost::tie(ei, ei_end) = edges(g); ei != ei_end; ++ei) { |
| graph_traits < graph_t >::edge_descriptor e = *ei; |
| graph_traits < graph_t >::vertex_descriptor |
| u = source(e, g), v = target(e, g); |
| dot_file << name[u] << " -> " << name[v] |
| << "[label=\"" << get(weightmap, e) << "\""; |
| if (p[v] == u) |
| dot_file << ", color=\"black\""; |
| else |
| dot_file << ", color=\"grey\""; |
| dot_file << "]"; |
| } |
| dot_file << "}"; |
| return EXIT_SUCCESS; |
| } |