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 | |
34 | namespace 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 | |