| //======================================================================= |
| // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. |
| // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek |
| // |
| // 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) |
| //======================================================================= |
| |
| /* |
| This file implements the function |
| |
| template <class VertexAndEdgeListGraph, class DistanceMatrix, |
| class P, class T, class R> |
| bool |
| johnson_all_pairs_shortest_paths |
| (VertexAndEdgeListGraph& g, |
| DistanceMatrix& D, |
| const bgl_named_params<P, T, R>& params) |
| */ |
| |
| #ifndef BOOST_GRAPH_JOHNSON_HPP |
| #define BOOST_GRAPH_JOHNSON_HPP |
| |
| #include <boost/graph/graph_traits.hpp> |
| #include <boost/property_map/property_map.hpp> |
| #include <boost/property_map/shared_array_property_map.hpp> |
| #include <boost/graph/bellman_ford_shortest_paths.hpp> |
| #include <boost/graph/dijkstra_shortest_paths.hpp> |
| #include <boost/graph/adjacency_list.hpp> |
| #include <boost/type_traits/same_traits.hpp> |
| |
| namespace boost { |
| |
| template <class VertexAndEdgeListGraph, class DistanceMatrix, |
| class VertexID, class Weight, typename BinaryPredicate, |
| typename BinaryFunction, typename Infinity, class DistanceZero> |
| bool |
| johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1, |
| DistanceMatrix& D, |
| VertexID id1, Weight w1, const BinaryPredicate& compare, |
| const BinaryFunction& combine, const Infinity& inf, |
| DistanceZero zero) |
| { |
| typedef graph_traits<VertexAndEdgeListGraph> Traits1; |
| typedef typename property_traits<Weight>::value_type DT; |
| function_requires< BasicMatrixConcept<DistanceMatrix, |
| typename Traits1::vertices_size_type, DT> >(); |
| |
| typedef typename Traits1::directed_category DirCat; |
| bool is_undirected = is_same<DirCat, undirected_tag>::value; |
| |
| typedef adjacency_list<vecS, vecS, directedS, |
| property< vertex_distance_t, DT>, |
| property< edge_weight_t, DT, |
| property< edge_weight2_t, DT > > > Graph2; |
| typedef graph_traits<Graph2> Traits2; |
| |
| Graph2 g2(num_vertices(g1) + 1); |
| typename property_map<Graph2, edge_weight_t>::type |
| w = get(edge_weight, g2); |
| typename property_map<Graph2, edge_weight2_t>::type |
| w_hat = get(edge_weight2, g2); |
| typename property_map<Graph2, vertex_distance_t>::type |
| d = get(vertex_distance, g2); |
| typedef typename property_map<Graph2, vertex_index_t>::type VertexID2; |
| VertexID2 id2 = get(vertex_index, g2); |
| |
| // Construct g2 where V[g2] = V[g1] U {s} |
| // and E[g2] = E[g1] U {(s,v)| v in V[g1]} |
| std::vector<typename Traits1::vertex_descriptor> |
| verts1(num_vertices(g1) + 1); |
| typename Traits2::vertex_descriptor s = *vertices(g2).first; |
| { |
| typename Traits1::vertex_iterator v, v_end; |
| int i = 1; |
| for (boost::tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i) { |
| typename Traits2::edge_descriptor e; bool z; |
| boost::tie(e, z) = add_edge(s, get(id1, *v) + 1, g2); |
| put(w, e, zero); |
| verts1[i] = *v; |
| } |
| typename Traits1::edge_iterator e, e_end; |
| for (boost::tie(e, e_end) = edges(g1); e != e_end; ++e) { |
| typename Traits2::edge_descriptor e2; bool z; |
| boost::tie(e2, z) = add_edge(get(id1, source(*e, g1)) + 1, |
| get(id1, target(*e, g1)) + 1, g2); |
| put(w, e2, get(w1, *e)); |
| if (is_undirected) { |
| boost::tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1, |
| get(id1, source(*e, g1)) + 1, g2); |
| put(w, e2, get(w1, *e)); |
| } |
| } |
| } |
| typename Traits2::vertex_iterator v, v_end, u, u_end; |
| typename Traits2::edge_iterator e, e_end; |
| shared_array_property_map<DT,VertexID2> h(num_vertices(g2), id2); |
| |
| for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v) |
| put(d, *v, inf); |
| |
| put(d, s, zero); |
| // Using the non-named parameter versions of bellman_ford and |
| // dijkstra for portability reasons. |
| dummy_property_map pred; bellman_visitor<> bvis; |
| if (bellman_ford_shortest_paths |
| (g2, num_vertices(g2), w, pred, d, combine, compare, bvis)) { |
| for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v) |
| put(h, *v, get(d, *v)); |
| // Reweight the edges to remove negatives |
| for (boost::tie(e, e_end) = edges(g2); e != e_end; ++e) { |
| typename Traits2::vertex_descriptor a = source(*e, g2), |
| b = target(*e, g2); |
| put(w_hat, *e, combine(get(w, *e), (get(h, a) - get(h, b)))); |
| } |
| for (boost::tie(u, u_end) = vertices(g2); u != u_end; ++u) { |
| dijkstra_visitor<> dvis; |
| dijkstra_shortest_paths |
| (g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero,dvis); |
| for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v) { |
| if (*u != s && *v != s) { |
| typename Traits1::vertex_descriptor u1, v1; |
| u1 = verts1[get(id2, *u)]; v1 = verts1[get(id2, *v)]; |
| D[get(id2, *u)-1][get(id2, *v)-1] = combine(get(d, *v), (get(h, *v) - get(h, *u))); |
| } |
| } |
| } |
| return true; |
| } else |
| return false; |
| } |
| |
| template <class VertexAndEdgeListGraph, class DistanceMatrix, |
| class VertexID, class Weight, class DistanceZero> |
| bool |
| johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1, |
| DistanceMatrix& D, |
| VertexID id1, Weight w1, DistanceZero zero) |
| { |
| typedef typename property_traits<Weight>::value_type WT; |
| return johnson_all_pairs_shortest_paths(g1, D, id1, w1, |
| std::less<WT>(), |
| closed_plus<WT>(), |
| (std::numeric_limits<WT>::max)(), |
| zero); |
| } |
| |
| namespace detail { |
| |
| template <class VertexAndEdgeListGraph, class DistanceMatrix, |
| class P, class T, class R, class Weight, |
| class VertexID> |
| bool |
| johnson_dispatch(VertexAndEdgeListGraph& g, |
| DistanceMatrix& D, |
| const bgl_named_params<P, T, R>& params, |
| Weight w, VertexID id) |
| { |
| typedef typename property_traits<Weight>::value_type WT; |
| |
| return johnson_all_pairs_shortest_paths |
| (g, D, id, w, |
| choose_param(get_param(params, distance_compare_t()), |
| std::less<WT>()), |
| choose_param(get_param(params, distance_combine_t()), |
| closed_plus<WT>()), |
| choose_param(get_param(params, distance_inf_t()), |
| std::numeric_limits<WT>::max BOOST_PREVENT_MACRO_SUBSTITUTION()), |
| choose_param(get_param(params, distance_zero_t()), WT()) ); |
| } |
| |
| } // namespace detail |
| |
| template <class VertexAndEdgeListGraph, class DistanceMatrix, |
| class P, class T, class R> |
| bool |
| johnson_all_pairs_shortest_paths |
| (VertexAndEdgeListGraph& g, |
| DistanceMatrix& D, |
| const bgl_named_params<P, T, R>& params) |
| { |
| return detail::johnson_dispatch |
| (g, D, params, |
| choose_const_pmap(get_param(params, edge_weight), g, edge_weight), |
| choose_const_pmap(get_param(params, vertex_index), g, vertex_index) |
| ); |
| } |
| |
| template <class VertexAndEdgeListGraph, class DistanceMatrix> |
| bool |
| johnson_all_pairs_shortest_paths |
| (VertexAndEdgeListGraph& g, DistanceMatrix& D) |
| { |
| bgl_named_params<int,int> params(1); |
| return detail::johnson_dispatch |
| (g, D, params, get(edge_weight, g), get(vertex_index, g)); |
| } |
| |
| } // namespace boost |
| |
| #endif // BOOST_GRAPH_JOHNSON_HPP |
| |
| |