http://www.perlmonks.org?node_id=940423


in reply to Lights out puzzle

Here's a quick Monday morning puzzle.
Quick?? I spent several hours on it, not being able to come with anything better then this: It's a bit randomized, but usually runs under 2 seconds on my machine. Run it with a filename as an argument to check the solution saved in the file.
Update: Removed forgotten debugging line.
Update2: Readmore changed to spoiler.