z-hypercake

This task is asking for the largest eigenvalue of the trade matrix.
Power iteration method fits pretty well. I pass the examples and get WA on all actual test cases.

Which part did I get wrong?

I think power iteration finds the eigenvalue with largest absolute value, rather than the largest itself. So a big negative eigenvalue could actually "hide" the true largest eigenvalue to this method.

Not 100% sure, though.