27ms == 0.027s How do you have a 16x16 grid for soduku? Are you using 16 digits? 0-F?
The one I am using has 9 digits, 9 squares of 9 cells each, or 9x9 cells. The least efficient part of the algorithm is that part to calculate what to put in a hole (as anyone might've guessed.) My algorithm calculates this by using a set of possible values. Then I visit each cell in the same row, column, and square, removing values from the set. What's left is the possible values. If there is only one possible value, then I've found what belongs there. The soduku puzzle I was using for a test can be solved without making any guesses in this way. The guy's algorithm was visiting each empty square and then trying out numbers from 1-9. If they didn't violate the rules (by examining each cell in the row, column, and square for each guess), then he would move to the next empty cell and try again, until he got the solution. There was a lot of backtracking and it would even try to find all possible answers. -- http://mail.python.org/mailman/listinfo/python-list
