Complexity

[OndrejPetrzilka]

It would be nice to add approximate calculation complexity into README file. Something like O(N * D * log(D)). Where N is number of points and D is dimension. (I don't know the actual complexity, that was just the example).

I didn't find this in the paper and it's hard to get it from code. From charts it seems something like O(N * D), I'm not sure that's right.