5 ms·

Others have pointed out that this is Lights Out. If anyone's interested, there is a known algorithm (PDF): https://linux.ime.usp.br/~renatolg/lights_out.pdf ht

• tzs 12y ago
  That's the clever solution. Here's a solution that is actually brute force, but tries to fake being clever: http://www.tzs.net/lights.html http://www.tzs.net/lights.html PS: I have not updated that page in years, which is why it contains a link to a Dutch noodle seller. It was a link to an online game service back when I wrote the page.