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/* -*- 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 print_matrix(const igraph_matrix_t *m) {
long int nrow=igraph_matrix_nrow(m);
long int ncol=igraph_matrix_ncol(m);
long int i, j;
for (i=0; i<nrow; i++) {
printf("%li:", i);
for (j=0; j<ncol; j++) {
printf(" %3.0F", MATRIX(*m, i, j));
}
printf("\n");
}
return 0;
}
int main() {
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(igraph_real_t));
igraph_matrix_init(&res, 0, 0);
igraph_shortest_paths_bellman_ford(&g, &res, igraph_vss_all(), igraph_vss_all(),
&weights, IGRAPH_OUT);
print_matrix(&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(igraph_real_t));
igraph_matrix_init(&res, 0, 0);
igraph_shortest_paths_bellman_ford(&g, &res, igraph_vss_all(),
igraph_vss_all(), &weights, IGRAPH_OUT);
print_matrix(&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(igraph_real_t));
if (igraph_shortest_paths_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;
}
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