3.1. igraph_isomorphic_vf2 — Isomorphism via VF2

3.1. `igraph_isomorphic_vf2` — Isomorphism via VF2

int igraph_isomorphic_vf2(const igraph_t *graph1, const igraph_t *graph2, 
			  igraph_bool_t *iso, igraph_vector_t *map12, 
			  igraph_vector_t *map21);

This function performs the VF2 algorithm via calling igraph_isomorphic_function_vf2().

Note that this function cannot be used for deciding subgraph isomorphism, use igraph_subisomorphic_vf2() for that.

Arguments:

`graph1`:	The first graph, may be directed or undirected.
`graph2`:	The second graph. It must have the same directedness as `graph1`, otherwise an error is reported.
`iso`:	Pointer to a logical constant, the result of the algorithm will be placed here.
`map12`:	Pointer to an initialized vector or a NULL pointer. If not a NULL pointer then the mapping from `graph1` to `graph2` is stored here. If the graphs are not isomorphic then the vector is cleared (ie. has zero elements).
`map21`:	Pointer to an initialized vector or a NULL pointer. If not a NULL pointer then the mapping from `graph2` to `graph1` is stored here. If the graphs are not isomorphic then the vector is cleared (ie. has zero elements).

Returns:

Error code.

Time complexity: exponential, what did you expect?