You are standing in the very corner of a 10 X 10 grid of dots. How many different ways are there to get to the opposite corner of the grid? You must travel through every node once, and only once. You cannot travel diagonally, and you may not go outside of the overall perimeter.

(In reply to Solution by Jonathan Chang)

Sorry Jonathan, wrong solution.

We are making some progress, you started in the corner and ended in a corner.  But you ended in the wrong corner.  Everybody nows and agrees that there are numerous ways to do what you did.  But the problem said the opposite corner.  And that is not possible.  See the table below, choose a start corner and finish in the end corner.

Start           End
 (1,1)       (10,10)
 (1,10)      (10,1)
 (10,10)     (1,1)
 (10,1)      (1,10)

I am looking forward at your solution.

Posted by Hugo on 2005-04-20 07:13:52