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
|
/* -*- mode: C -*- */
/*
IGraph library.
Copyright (C) 2008-2012 Gabor Csardi <csardi.gabor@gmail.com>
334 Harvard street, Cambridge, MA 02139 USA
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include <igraph.h>
int main(void) {
igraph_t g;
igraph_vector_t weights;
igraph_real_t weights_data_0[] = { 0, 2, 1, 0, 5, 2, 1, 1, 0, 2, 2, 8, 1, 1, 3, 1, 1, 4, 2, 1 };
igraph_real_t weights_data_1[] = { 6, 7, 8, -4, -2, -3, 9, 2, 7 };
igraph_real_t weights_data_2[] = { 6, 7, 2, -4, -2, -3, 9, 2, 7 };
igraph_matrix_t res;
/* Graph with only positive weights */
igraph_small(&g, 10, IGRAPH_DIRECTED,
0, 1, 0, 2, 0, 3, 1, 2, 1, 4, 1, 5,
2, 3, 2, 6, 3, 2, 3, 6,
4, 5, 4, 7, 5, 6, 5, 8, 5, 9,
7, 5, 7, 8, 8, 9,
5, 2,
2, 1,
-1);
igraph_vector_view(&weights, weights_data_0,
sizeof(weights_data_0) / sizeof(weights_data_0[0]));
igraph_matrix_init(&res, 0, 0);
igraph_distances_bellman_ford(&g, &res, igraph_vss_all(), igraph_vss_all(),
&weights, IGRAPH_OUT);
igraph_matrix_print(&res);
igraph_matrix_destroy(&res);
igraph_destroy(&g);
printf("\n");
/***************************************/
/* Graph with negative weights */
igraph_small(&g, 5, IGRAPH_DIRECTED,
0, 1, 0, 3, 1, 3, 1, 4, 2, 1, 3, 2, 3, 4, 4, 0, 4, 2, -1);
igraph_vector_view(&weights, weights_data_1,
sizeof(weights_data_1) / sizeof(weights_data_1[0]));
igraph_matrix_init(&res, 0, 0);
igraph_distances_bellman_ford(&g, &res, igraph_vss_all(),
igraph_vss_all(), &weights, IGRAPH_OUT);
igraph_matrix_print(&res);
/***************************************/
/* Same graph with negative loop */
igraph_set_error_handler(igraph_error_handler_ignore);
igraph_vector_view(&weights, weights_data_2,
sizeof(weights_data_2) / sizeof(weights_data_2[0]));
if (igraph_distances_bellman_ford(&g, &res, igraph_vss_all(),
igraph_vss_all(),
&weights, IGRAPH_OUT) != IGRAPH_ENEGLOOP) {
return 1;
}
igraph_matrix_destroy(&res);
igraph_destroy(&g);
if (!IGRAPH_FINALLY_STACK_EMPTY) {
return 1;
}
return 0;
}
|
