Hello, I am one of the participants of APIO 2025 (you can check at rank 44). The problems are really hard and tricky, and one of them is the 3rd problem — rotate. You guys can check the statements of APIO2025 in here: https://github.com/apio2025/apio2025_tasks.

I won't talk about the statement of the 3rd problem here since it's already in github; you guys should check that before reading my solution.

So, I don't know if this is the intended solution, but I think I am really lucky when I got accepted at 4h45. And that solution is really simple. Here's my solution:

I can't prove my solution, so can you guys check this and prove it for me, or is this solution wrong?

Thank you for reading this blog.