williamr@2: //=======================================================================
williamr@2: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
williamr@2: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
williamr@2: //
williamr@2: // Distributed under the Boost Software License, Version 1.0. (See
williamr@2: // accompanying file LICENSE_1_0.txt or copy at
williamr@2: // http://www.boost.org/LICENSE_1_0.txt)
williamr@2: //=======================================================================
williamr@2: 
williamr@2: /*
williamr@2:   This file implements the function
williamr@2: 
williamr@2:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
williamr@2:             class P, class T, class R>
williamr@2:   bool
williamr@2:   johnson_all_pairs_shortest_paths
williamr@2:     (VertexAndEdgeListGraph& g, 
williamr@2:      DistanceMatrix& D,
williamr@2:      const bgl_named_params<P, T, R>& params)
williamr@2:  */
williamr@2: 
williamr@2: #ifndef BOOST_GRAPH_JOHNSON_HPP
williamr@2: #define BOOST_GRAPH_JOHNSON_HPP
williamr@2: 
williamr@2: #include <boost/graph/graph_traits.hpp>
williamr@2: #include <boost/property_map.hpp>
williamr@2: #include <boost/graph/bellman_ford_shortest_paths.hpp>
williamr@2: #include <boost/graph/dijkstra_shortest_paths.hpp>
williamr@2: #include <boost/graph/adjacency_list.hpp>
williamr@2: #include <boost/pending/ct_if.hpp>
williamr@2: #include <boost/type_traits/same_traits.hpp>
williamr@2: 
williamr@2: namespace boost {
williamr@2: 
williamr@2:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
williamr@2:             class VertexID, class Weight, typename BinaryPredicate, 
williamr@2:             typename BinaryFunction, typename Infinity, class DistanceZero>
williamr@2:   bool
williamr@2:   johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1, 
williamr@2:                DistanceMatrix& D,
williamr@2:                VertexID id1, Weight w1, const BinaryPredicate& compare, 
williamr@2:                const BinaryFunction& combine, const Infinity& inf,
williamr@2:                DistanceZero zero)
williamr@2:   {
williamr@2:     typedef graph_traits<VertexAndEdgeListGraph> Traits1;
williamr@2:     typedef typename property_traits<Weight>::value_type DT;
williamr@2:     function_requires< BasicMatrixConcept<DistanceMatrix,
williamr@2:       typename Traits1::vertices_size_type, DT> >();
williamr@2: 
williamr@2:     typedef typename Traits1::directed_category DirCat;
williamr@2:     bool is_undirected = is_same<DirCat, undirected_tag>::value;
williamr@2: 
williamr@2:     typedef adjacency_list<vecS, vecS, directedS, 
williamr@2:       property< vertex_distance_t, DT>,
williamr@2:       property< edge_weight_t, DT, 
williamr@2:       property< edge_weight2_t, DT > > > Graph2;
williamr@2:     typedef graph_traits<Graph2> Traits2;
williamr@2: 
williamr@2:     Graph2 g2(num_vertices(g1) + 1);
williamr@2:     typename property_map<Graph2, edge_weight_t>::type 
williamr@2:       w = get(edge_weight, g2);
williamr@2:     typename property_map<Graph2, edge_weight2_t>::type 
williamr@2:       w_hat = get(edge_weight2, g2);
williamr@2:     typename property_map<Graph2, vertex_distance_t>::type 
williamr@2:       d = get(vertex_distance, g2);
williamr@2:     typedef typename property_map<Graph2, vertex_index_t>::type VertexID2;
williamr@2:     VertexID2 id2 = get(vertex_index, g2);
williamr@2: 
williamr@2:     // Construct g2 where V[g2] = V[g1] U {s}
williamr@2:     //   and  E[g2] = E[g1] U {(s,v)| v in V[g1]}
williamr@2:     std::vector<typename Traits1::vertex_descriptor> 
williamr@2:       verts1(num_vertices(g1) + 1);
williamr@2:     typename Traits2::vertex_descriptor s = *vertices(g2).first;
williamr@2:     {
williamr@2:       typename Traits1::vertex_iterator v, v_end;
williamr@2:       int i = 1;
williamr@2:       for (tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i) {
williamr@2:         typename Traits2::edge_descriptor e; bool z;
williamr@2:         tie(e, z) = add_edge(s, get(id1, *v) + 1, g2);
williamr@2:         put(w, e, zero);
williamr@2:         verts1[i] = *v;
williamr@2:       }
williamr@2:       typename Traits1::edge_iterator e, e_end;
williamr@2:       for (tie(e, e_end) = edges(g1); e != e_end; ++e) {
williamr@2:         typename Traits2::edge_descriptor e2; bool z;
williamr@2:         tie(e2, z) = add_edge(get(id1, source(*e, g1)) + 1, 
williamr@2:                               get(id1, target(*e, g1)) + 1, g2);
williamr@2:         put(w, e2, get(w1, *e));
williamr@2:         if (is_undirected) {
williamr@2:           tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1, 
williamr@2:                                 get(id1, source(*e, g1)) + 1, g2);
williamr@2:           put(w, e2, get(w1, *e));
williamr@2:         }
williamr@2:       }
williamr@2:     }
williamr@2:     typename Traits2::vertex_iterator v, v_end, u, u_end;
williamr@2:     typename Traits2::edge_iterator e, e_end;
williamr@2:     std::vector<DT> h_vec(num_vertices(g2));
williamr@2:     typedef typename std::vector<DT>::iterator iter_t;
williamr@2:     iterator_property_map<iter_t,VertexID2,DT,DT&> h(h_vec.begin(), id2);
williamr@2: 
williamr@2:     for (tie(v, v_end) = vertices(g2); v != v_end; ++v)
williamr@2:       d[*v] = inf;
williamr@2: 
williamr@2:     put(d, s, zero);
williamr@2:     // Using the non-named parameter versions of bellman_ford and
williamr@2:     // dijkstra for portability reasons.
williamr@2:     dummy_property_map pred; bellman_visitor<> bvis;
williamr@2:     if (bellman_ford_shortest_paths
williamr@2:         (g2, num_vertices(g2), w, pred, d, combine, compare, bvis)) {
williamr@2:       for (tie(v, v_end) = vertices(g2); v != v_end; ++v)
williamr@2:         put(h, *v, get(d, *v));
williamr@2:       // Reweight the edges to remove negatives
williamr@2:       for (tie(e, e_end) = edges(g2); e != e_end; ++e) {
williamr@2:         typename Traits2::vertex_descriptor a = source(*e, g2),
williamr@2:           b = target(*e, g2);
williamr@2:         put(w_hat, *e, get(w, *e) + get(h, a) - get(h, b));
williamr@2:       }
williamr@2:       for (tie(u, u_end) = vertices(g2); u != u_end; ++u) {
williamr@2:         dijkstra_visitor<> dvis;
williamr@2:         dijkstra_shortest_paths
williamr@2:           (g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero,dvis);
williamr@2:         for (tie(v, v_end) = vertices(g2); v != v_end; ++v) {
williamr@2:           if (*u != s && *v != s) {
williamr@2:             typename Traits1::vertex_descriptor u1, v1;
williamr@2:             u1 = verts1[id2[*u]]; v1 = verts1[id2[*v]];
williamr@2:             D[id2[*u]-1][id2[*v]-1] = get(d, *v) + get(h, *v) - get(h, *u);
williamr@2:           }
williamr@2:         }
williamr@2:       }
williamr@2:       return true;
williamr@2:     } else
williamr@2:       return false;
williamr@2:   }
williamr@2: 
williamr@2:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
williamr@2:             class VertexID, class Weight, class DistanceZero>
williamr@2:   bool
williamr@2:   johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1, 
williamr@2:                DistanceMatrix& D,
williamr@2:                VertexID id1, Weight w1, DistanceZero zero)
williamr@2:   {
williamr@2:     typedef typename property_traits<Weight>::value_type WT;
williamr@2:     return johnson_all_pairs_shortest_paths(g1, D, id1, w1, 
williamr@2:                                             std::less<WT>(),
williamr@2:                                             closed_plus<WT>(),
williamr@2:                                             (std::numeric_limits<WT>::max)(),
williamr@2:                                             zero);
williamr@2:   }
williamr@2: 
williamr@2:   namespace detail {
williamr@2: 
williamr@2:     template <class VertexAndEdgeListGraph, class DistanceMatrix,
williamr@2:               class P, class T, class R, class Weight, 
williamr@2:               class VertexID>
williamr@2:     bool
williamr@2:     johnson_dispatch(VertexAndEdgeListGraph& g, 
williamr@2:                      DistanceMatrix& D,
williamr@2:                      const bgl_named_params<P, T, R>& params,
williamr@2:                      Weight w, VertexID id)
williamr@2:     {
williamr@2:       typedef typename property_traits<Weight>::value_type WT;
williamr@2:       
williamr@2:       return johnson_all_pairs_shortest_paths
williamr@2:         (g, D, id, w,
williamr@2:         choose_param(get_param(params, distance_compare_t()), 
williamr@2:           std::less<WT>()),
williamr@2:         choose_param(get_param(params, distance_combine_t()), 
williamr@2:           closed_plus<WT>()),
williamr@2:         choose_param(get_param(params, distance_inf_t()), 
williamr@2:           std::numeric_limits<WT>::max BOOST_PREVENT_MACRO_SUBSTITUTION()),
williamr@2:          choose_param(get_param(params, distance_zero_t()), WT()) );
williamr@2:     }
williamr@2: 
williamr@2:   } // namespace detail
williamr@2: 
williamr@2:   template <class VertexAndEdgeListGraph, class DistanceMatrix,
williamr@2:             class P, class T, class R>
williamr@2:   bool
williamr@2:   johnson_all_pairs_shortest_paths
williamr@2:     (VertexAndEdgeListGraph& g, 
williamr@2:      DistanceMatrix& D,
williamr@2:      const bgl_named_params<P, T, R>& params)
williamr@2:   {
williamr@2:     return detail::johnson_dispatch
williamr@2:       (g, D, params,
williamr@2:        choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
williamr@2:        choose_const_pmap(get_param(params, vertex_index), g, vertex_index)
williamr@2:        );
williamr@2:   }
williamr@2: 
williamr@2:   template <class VertexAndEdgeListGraph, class DistanceMatrix>
williamr@2:   bool
williamr@2:   johnson_all_pairs_shortest_paths
williamr@2:     (VertexAndEdgeListGraph& g, DistanceMatrix& D)
williamr@2:   {
williamr@2:     bgl_named_params<int,int> params(1);
williamr@2:     return detail::johnson_dispatch
williamr@2:       (g, D, params, get(edge_weight, g), get(vertex_index, g));
williamr@2:   }
williamr@2: 
williamr@2: } // namespace boost
williamr@2: 
williamr@2: #endif // BOOST_GRAPH_JOHNSON_HPP
williamr@2: 
williamr@2: