Thread: 25x25 sudoku

Originally Posted by cpjust

When I do a sudoku on paper, I fill the blank spaces (in pencil so I can erase it later) with all the possible values that could go in there and usually do that to all the blank squares in a row or column. Then I see which numbers only appear once in that row, column or big square and that HAS to be the right number, so I erase the possible numbers in that square and fill in the real number. I also remove that number from all the other possible numbers in the large square... Rinse, Lather, Repeat until it's done.

Maybe you can use this "caching" technique in your algorithm?

I tried to make my sudoku program do that but it always ran into trouble when it encountered something along the line of

Code:

| 1 | 2 | 3 ||   |   |   ||   |   |   |
|   |   |   || 1 | 2 | 3 ||   |   |   |
|   |   |   ||   |   |   || 4 | 5 | 6 |