1//=======================================================================
2// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
3// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
4//
5// Distributed under the Boost Software License, Version 1.0. (See
6// accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt)
8//=======================================================================
9
10/*
11 This file implements the function
12
13 template <class VertexAndEdgeListGraph, class DistanceMatrix,
14 class P, class T, class R>
15 bool
16 johnson_all_pairs_shortest_paths
17 (VertexAndEdgeListGraph& g,
18 DistanceMatrix& D,
19 const bgl_named_params<P, T, R>& params)
20 */
21
22#ifndef BOOST_GRAPH_JOHNSON_HPP
23#define BOOST_GRAPH_JOHNSON_HPP
24
25#include <boost/graph/graph_traits.hpp>
26#include <boost/property_map/property_map.hpp>
27#include <boost/property_map/shared_array_property_map.hpp>
28#include <boost/graph/bellman_ford_shortest_paths.hpp>
29#include <boost/graph/dijkstra_shortest_paths.hpp>
30#include <boost/graph/adjacency_list.hpp>
31#include <boost/type_traits/same_traits.hpp>
32#include <boost/concept/assert.hpp>
33
34namespace boost {
35
36 template <class VertexAndEdgeListGraph, class DistanceMatrix,
37 class VertexID, class Weight, typename BinaryPredicate,
38 typename BinaryFunction, typename Infinity, class DistanceZero>
39 bool
40 johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
41 DistanceMatrix& D,
42 VertexID id1, Weight w1, const BinaryPredicate& compare,
43 const BinaryFunction& combine, const Infinity& inf,
44 DistanceZero zero)
45 {
46 typedef graph_traits<VertexAndEdgeListGraph> Traits1;
47 typedef typename property_traits<Weight>::value_type DT;
48 BOOST_CONCEPT_ASSERT(( BasicMatrixConcept<DistanceMatrix,
49 typename Traits1::vertices_size_type, DT> ));
50
51 typedef typename Traits1::directed_category DirCat;
52 bool is_undirected = is_same<DirCat, undirected_tag>::value;
53
54 typedef adjacency_list<vecS, vecS, directedS,
55 property< vertex_distance_t, DT>,
56 property< edge_weight_t, DT,
57 property< edge_weight2_t, DT > > > Graph2;
58 typedef graph_traits<Graph2> Traits2;
59
60 Graph2 g2(num_vertices(g1) + 1);
61 typename property_map<Graph2, edge_weight_t>::type
62 w = get(edge_weight, g2);
63 typename property_map<Graph2, edge_weight2_t>::type
64 w_hat = get(edge_weight2, g2);
65 typename property_map<Graph2, vertex_distance_t>::type
66 d = get(vertex_distance, g2);
67 typedef typename property_map<Graph2, vertex_index_t>::type VertexID2;
68 VertexID2 id2 = get(vertex_index, g2);
69
70 // Construct g2 where V[g2] = V[g1] U {s}
71 // and E[g2] = E[g1] U {(s,v)| v in V[g1]}
72 std::vector<typename Traits1::vertex_descriptor>
73 verts1(num_vertices(g1) + 1);
74 typename Traits2::vertex_descriptor s = *vertices(g2).first;
75 {
76 typename Traits1::vertex_iterator v, v_end;
77 int i = 1;
78 for (boost::tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i) {
79 typename Traits2::edge_descriptor e; bool z;
80 boost::tie(e, z) = add_edge(s, get(id1, *v) + 1, g2);
81 put(w, e, zero);
82 verts1[i] = *v;
83 }
84 typename Traits1::edge_iterator e, e_end;
85 for (boost::tie(e, e_end) = edges(g1); e != e_end; ++e) {
86 typename Traits2::edge_descriptor e2; bool z;
87 boost::tie(e2, z) = add_edge(get(id1, source(*e, g1)) + 1,
88 get(id1, target(*e, g1)) + 1, g2);
89 put(w, e2, get(w1, *e));
90 if (is_undirected) {
91 boost::tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1,
92 get(id1, source(*e, g1)) + 1, g2);
93 put(w, e2, get(w1, *e));
94 }
95 }
96 }
97 typename Traits2::vertex_iterator v, v_end, u, u_end;
98 typename Traits2::edge_iterator e, e_end;
99 shared_array_property_map<DT,VertexID2> h(num_vertices(g2), id2);
100
101 for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
102 put(d, *v, inf);
103
104 put(d, s, zero);
105 // Using the non-named parameter versions of bellman_ford and
106 // dijkstra for portability reasons.
107 dummy_property_map pred; bellman_visitor<> bvis;
108 if (bellman_ford_shortest_paths
109 (g2, num_vertices(g2), w, pred, d, combine, compare, bvis)) {
110 for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
111 put(h, *v, get(d, *v));
112 // Reweight the edges to remove negatives
113 for (boost::tie(e, e_end) = edges(g2); e != e_end; ++e) {
114 typename Traits2::vertex_descriptor a = source(*e, g2),
115 b = target(*e, g2);
116 put(w_hat, *e, combine((get(h, a) - get(h, b)), get(w, *e)));
117 }
118 for (boost::tie(u, u_end) = vertices(g2); u != u_end; ++u) {
119 dijkstra_visitor<> dvis;
120 dijkstra_shortest_paths
121 (g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero,dvis);
122 for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v) {
123 if (*u != s && *v != s) {
124 D[get(id2, *u)-1][get(id2, *v)-1] = combine((get(h, *v) - get(h, *u)), get(d, *v));
125 }
126 }
127 }
128 return true;
129 } else
130 return false;
131 }
132
133 template <class VertexAndEdgeListGraph, class DistanceMatrix,
134 class VertexID, class Weight, class DistanceZero>
135 bool
136 johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
137 DistanceMatrix& D,
138 VertexID id1, Weight w1, DistanceZero zero)
139 {
140 typedef typename property_traits<Weight>::value_type WT;
141 return johnson_all_pairs_shortest_paths(g1, D, id1, w1,
142 std::less<WT>(),
143 closed_plus<WT>(),
144 (std::numeric_limits<WT>::max)(),
145 zero);
146 }
147
148 namespace detail {
149
150 template <class VertexAndEdgeListGraph, class DistanceMatrix,
151 class P, class T, class R, class Weight,
152 class VertexID>
153 bool
154 johnson_dispatch(VertexAndEdgeListGraph& g,
155 DistanceMatrix& D,
156 const bgl_named_params<P, T, R>& params,
157 Weight w, VertexID id)
158 {
159 typedef typename property_traits<Weight>::value_type WT;
160
161 return johnson_all_pairs_shortest_paths
162 (g, D, id, w,
163 choose_param(get_param(params, distance_compare_t()),
164 std::less<WT>()),
165 choose_param(get_param(params, distance_combine_t()),
166 closed_plus<WT>()),
167 choose_param(get_param(params, distance_inf_t()),
168 std::numeric_limits<WT>::max BOOST_PREVENT_MACRO_SUBSTITUTION()),
169 choose_param(get_param(params, distance_zero_t()), WT()) );
170 }
171
172 } // namespace detail
173
174 template <class VertexAndEdgeListGraph, class DistanceMatrix,
175 class P, class T, class R>
176 bool
177 johnson_all_pairs_shortest_paths
178 (VertexAndEdgeListGraph& g,
179 DistanceMatrix& D,
180 const bgl_named_params<P, T, R>& params)
181 {
182 return detail::johnson_dispatch
183 (g, D, params,
184 choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
185 choose_const_pmap(get_param(params, vertex_index), g, vertex_index)
186 );
187 }
188
189 template <class VertexAndEdgeListGraph, class DistanceMatrix>
190 bool
191 johnson_all_pairs_shortest_paths
192 (VertexAndEdgeListGraph& g, DistanceMatrix& D)
193 {
194 bgl_named_params<int,int> params(1);
195 return detail::johnson_dispatch
196 (g, D, params, get(edge_weight, g), get(vertex_index, g));
197 }
198
199} // namespace boost
200
201#endif // BOOST_GRAPH_JOHNSON_HPP
202
203
204

source code of boost/boost/graph/johnson_all_pairs_shortest.hpp