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/* -*- mode: C -*- */
/*
IGraph library.
Copyright (C) 2006-2012 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>
#include <stdlib.h>
void free_complist(igraph_vector_ptr_t *complist) {
long int i;
for (i = 0; i < igraph_vector_ptr_size(complist); i++) {
igraph_destroy(VECTOR(*complist)[i]);
free(VECTOR(*complist)[i]);
}
}
int main() {
igraph_t ring, g;
igraph_vector_ptr_t complist;
long int i;
igraph_real_t edges[] = { 0, 1, 1, 2, 2, 0,
3, 4, 4, 5, 5, 6,
8, 9, 9, 10
};
igraph_vector_t v;
/* A ring, a single component */
igraph_ring(&ring, 10, IGRAPH_UNDIRECTED, 0, 1);
igraph_vector_ptr_init(&complist, 0);
igraph_decompose(&ring, &complist, IGRAPH_WEAK, -1, 0);
igraph_write_graph_edgelist(VECTOR(complist)[0], stdout);
free_complist(&complist);
igraph_destroy(&ring);
/* random graph with a giant component */
igraph_erdos_renyi_game(&g, IGRAPH_ERDOS_RENYI_GNP, 100, 4.0 / 100,
IGRAPH_UNDIRECTED, 0);
igraph_decompose(&g, &complist, IGRAPH_WEAK, -1, 20);
if (igraph_vector_ptr_size(&complist) != 1) {
return 1;
}
free_complist(&complist);
igraph_destroy(&g);
/* a toy graph, three components maximum, with at least 2 vertices each */
igraph_create(&g,
igraph_vector_view(&v, edges, sizeof(edges) / sizeof(igraph_real_t)),
0, IGRAPH_DIRECTED);
igraph_decompose(&g, &complist, IGRAPH_WEAK, 3, 2);
for (i = 0; i < igraph_vector_ptr_size(&complist); i++) {
igraph_write_graph_edgelist(VECTOR(complist)[i], stdout);
}
free_complist(&complist);
igraph_destroy(&g);
/* The same graph, this time with vertex attributes */
/* igraph_vector_init_seq(&idvect, 0, igraph_vcount(&g)-1); */
/* igraph_add_vertex_attribute(&g, "id", IGRAPH_ATTRIBUTE_NUM); */
/* igraph_set_vertex_attributes(&g, "id", IGRAPH_VS_ALL(&g), &idvect); */
/* igraph_vector_destroy(&idvect); */
/* igraph_decompose(&g, &complist, IGRAPH_WEAK, 3, 2); */
/* for (i=0; i<igraph_vector_ptr_size(&complist); i++) { */
/* igraph_t *comp=VECTOR(complist)[i]; */
/* igraph_es_t es; */
/* igraph_es_all(comp, &es); */
/* while (!igraph_es_end(comp, &es)) { */
/* igraph_real_t *from, *to; */
/* igraph_get_vertex_attribute(comp, "id", igraph_es_from(comp, &es), */
/* (void**) &from, 0); */
/* igraph_get_vertex_attribute(comp, "id", igraph_es_to(comp, &es), */
/* (void**) &to, 0); */
/* printf("%li %li\n", (long int) *from, (long int) *to); */
/* igraph_es_next(comp, &es); */
/* } */
/* } */
/* free_complist(&complist); */
/* igraph_destroy(&g); */
igraph_vector_ptr_destroy(&complist);
return 0;
}
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