Might just be me but I didn't think it was very clear that the input could have variable length rows & columns, and that the expected behaviour of "wrapping around" would be from e.g. index 8,10 to 7,6 when moving up if 7,6 is the furthest out index in that row. Could perhaps be made more explicit that this is the case.

I was so proud of my solution and now after reading this I feel dumb again lol,

1 day hopefully I can write algorithms this efficiently and with so much flare!

Thanks for the explanation!

Never mind, the piece of optimisation I failed to figure out was checking for a set rather than the entire string. My bad.

I continuously timed out with this exact solution...