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/*
IGraph library.
Copyright (C) 2006-2024 The igraph development team <igraph@igraph.org>
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, see <https://www.gnu.org/licenses/>.
*/
#include <igraph.h>
/* Prints a vector of edge IDs as u--v vertex pairs. */
void print_edge_vector(const igraph_t *graph, const igraph_vector_int_t *edges) {
const igraph_integer_t n = igraph_vector_int_size(edges);
for (igraph_integer_t i=0; i < n; i++) {
igraph_integer_t edge = VECTOR(*edges)[i];
printf("%" IGRAPH_PRId "--%" IGRAPH_PRId " ", IGRAPH_FROM(graph, edge), IGRAPH_TO(graph, edge));
}
printf("\n");
}
int main(void) {
igraph_t graph;
igraph_vector_int_list_t component_vertices, component_edges;
igraph_integer_t no;
/* Create an example graph. */
igraph_small(&graph, 7, IGRAPH_UNDIRECTED,
0,1, 1,2, 2,3, 3,0,
2,4, 4,5, 5,2,
0,6,
0,7,
-1);
/* The data structures that the result will be written to must be initialized first. */
igraph_vector_int_list_init(&component_vertices, 0);
igraph_vector_int_list_init(&component_edges, 0);
igraph_biconnected_components(&graph, &no, NULL, &component_edges, &component_vertices, NULL);
printf("Number of components: %" IGRAPH_PRId "\n", no);
for (igraph_integer_t i=0; i < no; i++) {
printf("\n");
printf("Component %" IGRAPH_PRId ":\n", i);
printf("Vertices: ");
igraph_vector_int_print(igraph_vector_int_list_get_ptr(&component_vertices, i));
printf("Edges: ");
print_edge_vector(&graph, igraph_vector_int_list_get_ptr(&component_edges, i));
}
/* Destroy data structures after we no longer need them. */
igraph_vector_int_list_destroy(&component_edges);
igraph_vector_int_list_destroy(&component_vertices);
igraph_destroy(&graph);
return 0;
}
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