Comment by phkahler

It would be a huge step to simply follow the call tree and report the depth of nested loops for each branch. You could then check what N is at each level.

The trick is knowing where the nested loops are since they can be spread across functions.

I had a function that scaled as N^2, but it was creating a list of that size as well. Then it called a function to remove duplicates from that list. That function was N^2, which meant the whole thing was actually N^4. And now that I think of it, those loops were not nested... I rewrote the first part to no create duplicates and deleted the quadratic deduplication. Now its N^2, but it has to be.