Chris@16: //=======================================================================
Chris@16: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
Chris@16: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //=======================================================================
Chris@16: 
Chris@16: /*
Chris@16:   This file implements the function
Chris@16: 
Chris@16:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
Chris@16:             class P, class T, class R>
Chris@16:   bool
Chris@16:   johnson_all_pairs_shortest_paths
Chris@16:     (VertexAndEdgeListGraph& g, 
Chris@16:      DistanceMatrix& D,
Chris@16:      const bgl_named_params<P, T, R>& params)
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_GRAPH_JOHNSON_HPP
Chris@16: #define BOOST_GRAPH_JOHNSON_HPP
Chris@16: 
Chris@16: #include <boost/graph/graph_traits.hpp>
Chris@16: #include <boost/property_map/property_map.hpp>
Chris@16: #include <boost/property_map/shared_array_property_map.hpp>
Chris@16: #include <boost/graph/bellman_ford_shortest_paths.hpp>
Chris@16: #include <boost/graph/dijkstra_shortest_paths.hpp>
Chris@16: #include <boost/graph/adjacency_list.hpp>
Chris@16: #include <boost/type_traits/same_traits.hpp>
Chris@16: #include <boost/concept/assert.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
Chris@16:             class VertexID, class Weight, typename BinaryPredicate, 
Chris@16:             typename BinaryFunction, typename Infinity, class DistanceZero>
Chris@16:   bool
Chris@16:   johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1, 
Chris@16:                DistanceMatrix& D,
Chris@16:                VertexID id1, Weight w1, const BinaryPredicate& compare, 
Chris@16:                const BinaryFunction& combine, const Infinity& inf,
Chris@16:                DistanceZero zero)
Chris@16:   {
Chris@16:     typedef graph_traits<VertexAndEdgeListGraph> Traits1;
Chris@16:     typedef typename property_traits<Weight>::value_type DT;
Chris@16:     BOOST_CONCEPT_ASSERT(( BasicMatrixConcept<DistanceMatrix,
Chris@16:       typename Traits1::vertices_size_type, DT> ));
Chris@16: 
Chris@16:     typedef typename Traits1::directed_category DirCat;
Chris@16:     bool is_undirected = is_same<DirCat, undirected_tag>::value;
Chris@16: 
Chris@16:     typedef adjacency_list<vecS, vecS, directedS, 
Chris@16:       property< vertex_distance_t, DT>,
Chris@16:       property< edge_weight_t, DT, 
Chris@16:       property< edge_weight2_t, DT > > > Graph2;
Chris@16:     typedef graph_traits<Graph2> Traits2;
Chris@16: 
Chris@16:     Graph2 g2(num_vertices(g1) + 1);
Chris@16:     typename property_map<Graph2, edge_weight_t>::type 
Chris@16:       w = get(edge_weight, g2);
Chris@16:     typename property_map<Graph2, edge_weight2_t>::type 
Chris@16:       w_hat = get(edge_weight2, g2);
Chris@16:     typename property_map<Graph2, vertex_distance_t>::type 
Chris@16:       d = get(vertex_distance, g2);
Chris@16:     typedef typename property_map<Graph2, vertex_index_t>::type VertexID2;
Chris@16:     VertexID2 id2 = get(vertex_index, g2);
Chris@16: 
Chris@16:     // Construct g2 where V[g2] = V[g1] U {s}
Chris@16:     //   and  E[g2] = E[g1] U {(s,v)| v in V[g1]}
Chris@16:     std::vector<typename Traits1::vertex_descriptor> 
Chris@16:       verts1(num_vertices(g1) + 1);
Chris@16:     typename Traits2::vertex_descriptor s = *vertices(g2).first;
Chris@16:     {
Chris@16:       typename Traits1::vertex_iterator v, v_end;
Chris@16:       int i = 1;
Chris@16:       for (boost::tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i) {
Chris@16:         typename Traits2::edge_descriptor e; bool z;
Chris@16:         boost::tie(e, z) = add_edge(s, get(id1, *v) + 1, g2);
Chris@16:         put(w, e, zero);
Chris@16:         verts1[i] = *v;
Chris@16:       }
Chris@16:       typename Traits1::edge_iterator e, e_end;
Chris@16:       for (boost::tie(e, e_end) = edges(g1); e != e_end; ++e) {
Chris@16:         typename Traits2::edge_descriptor e2; bool z;
Chris@16:         boost::tie(e2, z) = add_edge(get(id1, source(*e, g1)) + 1, 
Chris@16:                                      get(id1, target(*e, g1)) + 1, g2);
Chris@16:         put(w, e2, get(w1, *e));
Chris@16:         if (is_undirected) {
Chris@16:           boost::tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1, 
Chris@16:                                        get(id1, source(*e, g1)) + 1, g2);
Chris@16:           put(w, e2, get(w1, *e));
Chris@16:         }
Chris@16:       }
Chris@16:     }
Chris@16:     typename Traits2::vertex_iterator v, v_end, u, u_end;
Chris@16:     typename Traits2::edge_iterator e, e_end;
Chris@16:     shared_array_property_map<DT,VertexID2> h(num_vertices(g2), id2);
Chris@16: 
Chris@16:     for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
Chris@16:       put(d, *v, inf);
Chris@16: 
Chris@16:     put(d, s, zero);
Chris@16:     // Using the non-named parameter versions of bellman_ford and
Chris@16:     // dijkstra for portability reasons.
Chris@16:     dummy_property_map pred; bellman_visitor<> bvis;
Chris@16:     if (bellman_ford_shortest_paths
Chris@16:         (g2, num_vertices(g2), w, pred, d, combine, compare, bvis)) {
Chris@16:       for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
Chris@16:         put(h, *v, get(d, *v));
Chris@16:       // Reweight the edges to remove negatives
Chris@16:       for (boost::tie(e, e_end) = edges(g2); e != e_end; ++e) {
Chris@16:         typename Traits2::vertex_descriptor a = source(*e, g2),
Chris@16:           b = target(*e, g2);
Chris@16:         put(w_hat, *e, combine((get(h, a) - get(h, b)), get(w, *e)));
Chris@16:       }
Chris@16:       for (boost::tie(u, u_end) = vertices(g2); u != u_end; ++u) {
Chris@16:         dijkstra_visitor<> dvis;
Chris@16:         dijkstra_shortest_paths
Chris@16:           (g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero,dvis);
Chris@16:         for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v) {
Chris@16:           if (*u != s && *v != s) {
Chris@16:             D[get(id2, *u)-1][get(id2, *v)-1] = combine((get(h, *v) - get(h, *u)), get(d, *v));
Chris@16:           }
Chris@16:         }
Chris@16:       }
Chris@16:       return true;
Chris@16:     } else
Chris@16:       return false;
Chris@16:   }
Chris@16: 
Chris@16:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
Chris@16:             class VertexID, class Weight, class DistanceZero>
Chris@16:   bool
Chris@16:   johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1, 
Chris@16:                DistanceMatrix& D,
Chris@16:                VertexID id1, Weight w1, DistanceZero zero)
Chris@16:   {
Chris@16:     typedef typename property_traits<Weight>::value_type WT;
Chris@16:     return johnson_all_pairs_shortest_paths(g1, D, id1, w1, 
Chris@16:                                             std::less<WT>(),
Chris@16:                                             closed_plus<WT>(),
Chris@16:                                             (std::numeric_limits<WT>::max)(),
Chris@16:                                             zero);
Chris@16:   }
Chris@16: 
Chris@16:   namespace detail {
Chris@16: 
Chris@16:     template <class VertexAndEdgeListGraph, class DistanceMatrix,
Chris@16:               class P, class T, class R, class Weight, 
Chris@16:               class VertexID>
Chris@16:     bool
Chris@16:     johnson_dispatch(VertexAndEdgeListGraph& g, 
Chris@16:                      DistanceMatrix& D,
Chris@16:                      const bgl_named_params<P, T, R>& params,
Chris@16:                      Weight w, VertexID id)
Chris@16:     {
Chris@16:       typedef typename property_traits<Weight>::value_type WT;
Chris@16:       
Chris@16:       return johnson_all_pairs_shortest_paths
Chris@16:         (g, D, id, w,
Chris@16:         choose_param(get_param(params, distance_compare_t()), 
Chris@16:           std::less<WT>()),
Chris@16:         choose_param(get_param(params, distance_combine_t()), 
Chris@16:           closed_plus<WT>()),
Chris@16:         choose_param(get_param(params, distance_inf_t()), 
Chris@16:           std::numeric_limits<WT>::max BOOST_PREVENT_MACRO_SUBSTITUTION()),
Chris@16:          choose_param(get_param(params, distance_zero_t()), WT()) );
Chris@16:     }
Chris@16: 
Chris@16:   } // namespace detail
Chris@16: 
Chris@16:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
Chris@16:             class P, class T, class R>
Chris@16:   bool
Chris@16:   johnson_all_pairs_shortest_paths
Chris@16:     (VertexAndEdgeListGraph& g, 
Chris@16:      DistanceMatrix& D,
Chris@16:      const bgl_named_params<P, T, R>& params)
Chris@16:   {
Chris@16:     return detail::johnson_dispatch
Chris@16:       (g, D, params,
Chris@16:        choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
Chris@16:        choose_const_pmap(get_param(params, vertex_index), g, vertex_index)
Chris@16:        );
Chris@16:   }
Chris@16: 
Chris@16:   template <class VertexAndEdgeListGraph, class DistanceMatrix>
Chris@16:   bool
Chris@16:   johnson_all_pairs_shortest_paths
Chris@16:     (VertexAndEdgeListGraph& g, DistanceMatrix& D)
Chris@16:   {
Chris@16:     bgl_named_params<int,int> params(1);
Chris@16:     return detail::johnson_dispatch
Chris@16:       (g, D, params, get(edge_weight, g), get(vertex_index, g));
Chris@16:   }
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_GRAPH_JOHNSON_HPP
Chris@16: 
Chris@16: