1 
2 #include <igraph.h>
3 
main()4 int main() {
5     igraph_t graph;
6     igraph_vector_t component_sizes;
7 
8     igraph_rng_seed(igraph_rng_default(), 42); /* make program deterministic */
9 
10     /* Sample a graph from the Erdős-Rényi G(n,m) model */
11 
12     igraph_erdos_renyi_game(
13                 &graph, IGRAPH_ERDOS_RENYI_GNM,
14                 /* n= */ 100, /* m= */ 100,
15                 IGRAPH_UNDIRECTED, IGRAPH_NO_LOOPS);
16 
17     /* Compute the fraction of vertices contained within the largest connected component */
18 
19     igraph_vector_init(&component_sizes, 0);
20     igraph_clusters(&graph, NULL, &component_sizes, NULL, IGRAPH_STRONG);
21 
22     printf("Fraction of vertices in giant component: %g\n", (double) igraph_vector_max(&component_sizes) / igraph_vcount(&graph));
23 
24     /* Clean up data structures when no longer needed */
25 
26     igraph_vector_destroy(&component_sizes);
27     igraph_destroy(&graph);
28 
29     return 0;
30 }
31