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
37 template < class VertexAndEdgeListGraph, class DistanceMatrix, class VertexID,
38 class Weight, typename BinaryPredicate, typename BinaryFunction,
39 typename Infinity, class DistanceZero >
johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph & g1,DistanceMatrix & D,VertexID id1,Weight w1,const BinaryPredicate & compare,const BinaryFunction & combine,const Infinity & inf,DistanceZero zero)40 bool johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
41 DistanceMatrix& D, VertexID id1, Weight w1, const BinaryPredicate& compare,
42 const BinaryFunction& combine, const Infinity& inf, DistanceZero zero)
43 {
44 typedef graph_traits< VertexAndEdgeListGraph > Traits1;
45 typedef typename property_traits< Weight >::value_type DT;
46 BOOST_CONCEPT_ASSERT((BasicMatrixConcept< DistanceMatrix,
47 typename Traits1::vertices_size_type, DT >));
48
49 typedef typename Traits1::directed_category DirCat;
50 bool is_undirected = is_same< DirCat, undirected_tag >::value;
51
52 typedef adjacency_list< vecS, vecS, directedS,
53 property< vertex_distance_t, DT >,
54 property< edge_weight_t, DT, property< edge_weight2_t, DT > > >
55 Graph2;
56 typedef graph_traits< Graph2 > Traits2;
57
58 Graph2 g2(num_vertices(g1) + 1);
59 typename property_map< Graph2, edge_weight_t >::type w
60 = get(edge_weight, g2);
61 typename property_map< Graph2, edge_weight2_t >::type w_hat
62 = get(edge_weight2, g2);
63 typename property_map< Graph2, vertex_distance_t >::type d
64 = get(vertex_distance, g2);
65 typedef typename property_map< Graph2, vertex_index_t >::type VertexID2;
66 VertexID2 id2 = get(vertex_index, g2);
67
68 // Construct g2 where V[g2] = V[g1] U {s}
69 // and E[g2] = E[g1] U {(s,v)| v in V[g1]}
70 std::vector< typename Traits1::vertex_descriptor > verts1(
71 num_vertices(g1) + 1);
72 typename Traits2::vertex_descriptor s = *vertices(g2).first;
73 {
74 typename Traits1::vertex_iterator v, v_end;
75 int i = 1;
76 for (boost::tie(v, v_end) = vertices(g1); v != v_end; ++v, ++i)
77 {
78 typename Traits2::edge_descriptor e;
79 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 {
87 typename Traits2::edge_descriptor e2;
88 bool z;
89 boost::tie(e2, z) = add_edge(
90 get(id1, source(*e, g1)) + 1, get(id1, target(*e, g1)) + 1, g2);
91 put(w, e2, get(w1, *e));
92 if (is_undirected)
93 {
94 boost::tie(e2, z) = add_edge(get(id1, target(*e, g1)) + 1,
95 get(id1, source(*e, g1)) + 1, g2);
96 put(w, e2, get(w1, *e));
97 }
98 }
99 }
100 typename Traits2::vertex_iterator v, v_end, u, u_end;
101 typename Traits2::edge_iterator e, e_end;
102 shared_array_property_map< DT, VertexID2 > h(num_vertices(g2), id2);
103
104 for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
105 put(d, *v, inf);
106
107 put(d, s, zero);
108 // Using the non-named parameter versions of bellman_ford and
109 // dijkstra for portability reasons.
110 dummy_property_map pred;
111 bellman_visitor<> bvis;
112 if (bellman_ford_shortest_paths(
113 g2, num_vertices(g2), w, pred, d, combine, compare, bvis))
114 {
115 for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
116 put(h, *v, get(d, *v));
117 // Reweight the edges to remove negatives
118 for (boost::tie(e, e_end) = edges(g2); e != e_end; ++e)
119 {
120 typename Traits2::vertex_descriptor a = source(*e, g2),
121 b = target(*e, g2);
122 put(w_hat, *e, combine((get(h, a) - get(h, b)), get(w, *e)));
123 }
124 for (boost::tie(u, u_end) = vertices(g2); u != u_end; ++u)
125 {
126 dijkstra_visitor<> dvis;
127 dijkstra_shortest_paths(
128 g2, *u, pred, d, w_hat, id2, compare, combine, inf, zero, dvis);
129 for (boost::tie(v, v_end) = vertices(g2); v != v_end; ++v)
130 {
131 if (*u != s && *v != s)
132 {
133 D[get(id2, *u) - 1][get(id2, *v) - 1]
134 = combine((get(h, *v) - get(h, *u)), get(d, *v));
135 }
136 }
137 }
138 return true;
139 }
140 else
141 return false;
142 }
143
144 template < class VertexAndEdgeListGraph, class DistanceMatrix, class VertexID,
145 class Weight, class DistanceZero >
johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph & g1,DistanceMatrix & D,VertexID id1,Weight w1,DistanceZero zero)146 bool johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g1,
147 DistanceMatrix& D, VertexID id1, Weight w1, DistanceZero zero)
148 {
149 typedef typename property_traits< Weight >::value_type WT;
150 return johnson_all_pairs_shortest_paths(g1, D, id1, w1, std::less< WT >(),
151 closed_plus< WT >(), (std::numeric_limits< WT >::max)(), zero);
152 }
153
154 namespace detail
155 {
156
157 template < class VertexAndEdgeListGraph, class DistanceMatrix, class P,
158 class T, class R, class Weight, class VertexID >
johnson_dispatch(VertexAndEdgeListGraph & g,DistanceMatrix & D,const bgl_named_params<P,T,R> & params,Weight w,VertexID id)159 bool johnson_dispatch(VertexAndEdgeListGraph& g, DistanceMatrix& D,
160 const bgl_named_params< P, T, R >& params, Weight w, VertexID id)
161 {
162 typedef typename property_traits< Weight >::value_type WT;
163
164 return johnson_all_pairs_shortest_paths(g, D, id, w,
165 choose_param(
166 get_param(params, distance_compare_t()), std::less< WT >()),
167 choose_param(
168 get_param(params, distance_combine_t()), closed_plus< WT >()),
169 choose_param(get_param(params, distance_inf_t()),
170 std::numeric_limits< WT >::max
171 BOOST_PREVENT_MACRO_SUBSTITUTION()),
172 choose_param(get_param(params, distance_zero_t()), WT()));
173 }
174
175 } // namespace detail
176
177 template < class VertexAndEdgeListGraph, class DistanceMatrix, class P, class T,
178 class R >
johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph & g,DistanceMatrix & D,const bgl_named_params<P,T,R> & params)179 bool johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph& g,
180 DistanceMatrix& D, const bgl_named_params< P, T, R >& params)
181 {
182 return detail::johnson_dispatch(g, D, params,
183 choose_const_pmap(get_param(params, edge_weight), g, edge_weight),
184 choose_const_pmap(get_param(params, vertex_index), g, vertex_index));
185 }
186
187 template < class VertexAndEdgeListGraph, class DistanceMatrix >
johnson_all_pairs_shortest_paths(VertexAndEdgeListGraph & g,DistanceMatrix & D)188 bool johnson_all_pairs_shortest_paths(
189 VertexAndEdgeListGraph& g, DistanceMatrix& D)
190 {
191 bgl_named_params< int, int > params(1);
192 return detail::johnson_dispatch(
193 g, D, params, get(edge_weight, g), get(vertex_index, g));
194 }
195
196 } // namespace boost
197
198 #endif // BOOST_GRAPH_JOHNSON_HPP
199