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