Graph Equivalence

I want to talk about some interesting graph processing I've done recently. As a part of a bigger problem, I needed to collate a few millions of (not that large) graphs, replacing every set of equivalent graphs with a single graph and a count. I haven't found much on the internets about the graph equivalency, all I've found is people asking about it and other people whining that it's a hard problem. Well, yeah, if you brute-force it, it's obviously a factorial-scale problem. But I believe I've found a polynomial solution for it, with not such a high power, and I want to share it. It's kind of simple in the hindsight but it took me four versions of the algorithm and a couple of months of background thinking to get there, so I'm kind of proud of it.

The details are in my other blog:

1: The overall algorithm 2: Comparing the graph signatures 3: Why it works, simplified version 4: Why it works 5: Resolving the hash collisions 6: Optimizations