I want to divide the surface of a donut into as many different regions as possible. The regions can be any shape, as long as they are each in one piece. Each region must touch each of the other regions (touching on a corner doesn't count). How many regions can I make?

(In reply to An idea -- solution? (don't know if maximum is achieved) by Charlie)

That is a correct solution.  I'll try to make such a nice and clear diagram for my solution, this would make it easier to verify.

Posted by Hugo on 2005-04-23 20:33:56