[857] | 1 | //=======================================================================
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| 2 | // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
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| 3 | // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
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| 4 | //
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| 5 | // Distributed under the Boost Software License, Version 1.0. (See
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| 6 | // accompanying file LICENSE_1_0.txt or copy at
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| 7 | // http://www.boost.org/LICENSE_1_0.txt)
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| 8 | //=======================================================================
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| 9 |
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| 10 | /*
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| 11 | This file implements the function
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| 12 |
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| 13 | template <class VertexAndEdgeListGraph, class DistanceMatrix,
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| 14 | class P, class T, class R>
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| 15 | bool
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| 16 | johnson_all_pairs_shortest_paths
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| 17 | (VertexAndEdgeListGraph& g,
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| 18 | DistanceMatrix& D,
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| 19 | const bgl_named_params<P, T, R>& params)
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| 20 | */
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| 21 |
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| 22 | #ifndef BOOST_GRAPH_JOHNSON_HPP
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| 23 | #define BOOST_GRAPH_JOHNSON_HPP
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| 24 |
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| 25 | #include <boost/graph/graph_traits.hpp>
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| 26 | #include <boost/property_map.hpp>
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| 27 | #include <boost/graph/bellman_ford_shortest_paths.hpp>
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| 28 | #include <boost/graph/dijkstra_shortest_paths.hpp>
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| 29 | #include <boost/graph/adjacency_list.hpp>
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| 30 | #include <boost/pending/ct_if.hpp>
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| 31 | #include <boost/type_traits/same_traits.hpp>
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| 32 |
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| 33 | namespace boost {
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| 34 |
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| 35 | template <class VertexAndEdgeListGraph, class DistanceMatrix,
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| 36 | class VertexID, class Weight, class DistanceZero>
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| 37 | bool
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| 38 | johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
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| 39 | DistanceMatrix& D,
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| 40 | VertexID id1, Weight w1, DistanceZero zero)
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| 41 | {
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| 42 | typedef graph_traits<VertexAndEdgeListGraph> Traits1;
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| 43 | typedef typename property_traits<Weight>::value_type DT;
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| 44 | function_requires< BasicMatrixConcept<DistanceMatrix,
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| 45 | typename Traits1::vertices_size_type, DT> >();
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| 46 |
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| 47 | typedef typename Traits1::directed_category DirCat;
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| 48 | bool is_undirected = is_same<DirCat, undirected_tag>::value;
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| 49 |
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| 50 | typedef adjacency_list<vecS, vecS, directedS,
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| 51 | property< vertex_distance_t, DT>,
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| 52 | property< edge_weight_t, DT,
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| 53 | property< edge_weight2_t, DT > > > Graph2;
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| 54 | typedef graph_traits<Graph2> Traits2;
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| 55 |
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| 56 | Graph2 g2(num_vertices(g1) + 1);
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| 57 | typename property_map<Graph2, edge_weight_t>::type
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| 58 | w = get(edge_weight, g2);
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| 59 | typename property_map<Graph2, edge_weight2_t>::type
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| 60 | w_hat = get(edge_weight2, g2);
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| 61 | typename property_map<Graph2, vertex_distance_t>::type
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| 62 | d = get(vertex_distance, g2);
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| 63 | typedef typename property_map<Graph2, vertex_index_t>::type VertexID2;
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| 64 | VertexID2 id2 = get(vertex_index, g2);
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| 65 |
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| 66 | // Construct g2 where V[g2] = V[g1] U {s}
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| 67 | // and E[g2] = E[g1] U {(s,v)| v in V[g1]}
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| 68 | std::vector<typename Traits1::vertex_descriptor>
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| 69 | verts1(num_vertices(g1) + 1);
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| 70 | typename Traits2::vertex_descriptor s = *vertices(g2).first;
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| 71 | {
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| 72 | typename Traits1::vertex_iterator v, v_end;
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| 73 | int i = 1;
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| 74 | for (tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i) {
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| 75 | typename Traits2::edge_descriptor e; bool z;
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| 76 | tie(e, z) = add_edge(s, get(id1, *v) + 1, g2);
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| 77 | put(w, e, zero);
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| 78 | verts1[i] = *v;
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| 79 | }
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| 80 | typename Traits1::edge_iterator e, e_end;
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| 81 | for (tie(e, e_end) = edges(g1); e != e_end; ++e) {
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| 82 | typename Traits2::edge_descriptor e2; bool z;
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| 83 | tie(e2, z) = add_edge(get(id1, source(*e, g1)) + 1,
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| 84 | get(id1, target(*e, g1)) + 1, g2);
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| 85 | put(w, e2, get(w1, *e));
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| 86 | if (is_undirected) {
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| 87 | tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1,
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| 88 | get(id1, source(*e, g1)) + 1, g2);
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| 89 | put(w, e2, get(w1, *e));
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| 90 | }
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| 91 | }
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| 92 | }
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| 93 | typename Traits2::vertex_iterator v, v_end, u, u_end;
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| 94 | typename Traits2::edge_iterator e, e_end;
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| 95 | std::vector<DT> h_vec(num_vertices(g2));
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| 96 | typedef typename std::vector<DT>::iterator iter_t;
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| 97 | iterator_property_map<iter_t,VertexID2,DT,DT&> h(h_vec.begin(), id2);
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| 98 |
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| 99 | DT inf = (std::numeric_limits<DT>::max)();
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| 100 | for (tie(v, v_end) = vertices(g2); v != v_end; ++v)
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| 101 | d[*v] = inf;
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| 102 |
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| 103 | put(d, s, zero);
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| 104 | // Using the non-named parameter versions of bellman_ford and
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| 105 | // dijkstra for portability reasons.
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| 106 | dummy_property_map pred; closed_plus<DT> combine;
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| 107 | std::less<DT> compare; bellman_visitor<> bvis;
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| 108 | if (bellman_ford_shortest_paths
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| 109 | (g2, num_vertices(g2), w, pred, d, combine, compare, bvis)) {
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| 110 | for (tie(v, v_end) = vertices(g2); v != v_end; ++v)
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| 111 | put(h, *v, get(d, *v));
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| 112 | // Reweight the edges to remove negatives
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| 113 | for (tie(e, e_end) = edges(g2); e != e_end; ++e) {
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| 114 | typename Traits2::vertex_descriptor a = source(*e, g2),
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| 115 | b = target(*e, g2);
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| 116 | put(w_hat, *e, get(w, *e) + get(h, a) - get(h, b));
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| 117 | }
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| 118 | for (tie(u, u_end) = vertices(g2); u != u_end; ++u) {
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| 119 | dijkstra_visitor<> dvis;
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| 120 | dijkstra_shortest_paths
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| 121 | (g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero,dvis);
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| 122 | for (tie(v, v_end) = vertices(g2); v != v_end; ++v) {
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| 123 | if (*u != s && *v != s) {
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| 124 | typename Traits1::vertex_descriptor u1, v1;
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| 125 | u1 = verts1[id2[*u]]; v1 = verts1[id2[*v]];
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| 126 | D[id2[*u]-1][id2[*v]-1] = get(d, *v) + get(h, *v) - get(h, *u);
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| 127 | }
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| 128 | }
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| 129 | }
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| 130 | return true;
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| 131 | } else
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| 132 | return false;
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| 133 | }
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| 134 |
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| 135 | namespace detail {
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| 136 |
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| 137 | template <class VertexAndEdgeListGraph, class DistanceMatrix,
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| 138 | class P, class T, class R, class Weight,
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| 139 | class VertexID>
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| 140 | bool
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| 141 | johnson_dispatch(VertexAndEdgeListGraph& g,
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| 142 | DistanceMatrix& D,
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| 143 | const bgl_named_params<P, T, R>& params,
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| 144 | Weight w, VertexID id)
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| 145 | {
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| 146 | typedef typename property_traits<Weight>::value_type WT;
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| 147 |
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| 148 | return johnson_all_pairs_shortest_paths
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| 149 | (g, D, id, w,
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| 150 | choose_param(get_param(params, distance_zero_t()), WT()) );
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| 151 | }
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| 152 |
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| 153 | } // namespace detail
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| 154 |
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| 155 | template <class VertexAndEdgeListGraph, class DistanceMatrix,
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| 156 | class P, class T, class R>
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| 157 | bool
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| 158 | johnson_all_pairs_shortest_paths
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| 159 | (VertexAndEdgeListGraph& g,
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| 160 | DistanceMatrix& D,
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| 161 | const bgl_named_params<P, T, R>& params)
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| 162 | {
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| 163 | return detail::johnson_dispatch
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| 164 | (g, D, params,
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| 165 | choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
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| 166 | choose_const_pmap(get_param(params, vertex_index), g, vertex_index)
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| 167 | );
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| 168 | }
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| 169 |
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| 170 | template <class VertexAndEdgeListGraph, class DistanceMatrix>
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| 171 | bool
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| 172 | johnson_all_pairs_shortest_paths
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| 173 | (VertexAndEdgeListGraph& g, DistanceMatrix& D)
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| 174 | {
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| 175 | bgl_named_params<int,int> params(1);
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| 176 | return detail::johnson_dispatch
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| 177 | (g, D, params, get(edge_weight, g), get(vertex_index, g));
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| 178 | }
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| 179 |
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| 180 | } // namespace boost
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| 181 |
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| 182 | #endif // BOOST_GRAPH_JOHNSON_HPP
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| 183 |
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| 184 |
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