VF2++

A state-of-the-art algorithm for the Graph Isomorphism problem, adjusted for the Sub-Graph and
Induced Sub-Graph Isomorphism problems and extended to directed and multigraph settings.

The benchmark results validate the premises of the VF2++ paper and illustrate the superiority of the new optimized algorithm, compared to the previous isomorphism solvers.

This implementation is done in a non-recursive manner, saving a lot of space compared to previous recursive solvers.