I love this kata too. It took me a week of thinking and observation to find the underlying pattern. If you generate XOR matrix from zero indexed rows and columns, you will be able to see they follow a unique (but very complex) pattern. Once you identify the pattern, then it is a matter of writing recursive or similar functions. Brute force attack will definitely not work. I have solved it with simple maths as I am not much familiar with bitwise arithmetic.

Rule 0 in algorithm problems: Don't fine-tune an algorithm that has the wrong complexity ;-) The 7th test should give you a good idea what the required complexity is like.

So far most people have success by finding the underlying pattern. Unless you know a certain secret, I'm afraid you'll have to go down that path too ;-)

why have you logged an issue? Please dont log issues just because you feel like it.