oh my days, I cannot believe I misread that. Thank you for bring it into light. I should've paid more attention. That makes the problem even easier to solve.

Oh I see. I get it now.

I like the use of mem::swap on gcd() function. Good work!

I don't even understand why you'd need this kind of code. It's unreadable and invokes a lot of unnecessary concepts.

@Kerlin I too used the quadratic solution and for some reason, a test fails in the main test. All sample tests pass. It would be better if we could see those tests. Strange how it's now working.

Recursion is slower than running a loop. So I'll pass thank you.