3.2. igraph_count_isomorphisms_vf2 — Number of isomorphisms via VF2

int igraph_count_isomorphisms_vf2(const igraph_t *graph1, const igraph_t *graph2, 
				  igraph_integer_t *count);

This function counts the number of isomorphic mappings between two graphs. It uses the generic igraph_isomorphic_function_vf2() function.

Arguments:

`graph1`:	The first input graph, may be directed or undirected.
`graph2`:	The second input graph, it must have the same directedness as `graph1`, or an error will be reported.
`count`:	Point to an integer, the result will be stored here.

Returns:

Error code.

Time complexity: exponential.