A computer science teacher poses his students a problem.

"I want you write a computer program that plays tic-tac-toe legally and runs through ALL the possible combinations of the game, and finds out the total."

The students settle down to work..

An hour later, a student gets up and proclaims "I've got it! The number of possible combinations in a game is 344,242."

At which point another student quickly replies, "I haven't finished yet, but I'm sure Fred made a mistake in his program."

Why?

(Tic Tac Toe = Noughts and Crosses)

Every complete game has three other distinct counterparts that represent 90-, 180-, and 270-degree rotations of the same game. 344,242 is not divisible by four (by inspection of the last two digits), so it can't be an accurate tally of all possible games.

Posted by friedlinguini on 2002-09-27 12:21:03