This is a program for solving the little Japanese number crosswords
that have been popping up all over newspapers and the web lately. They are known
as Sudoku and can be quite frustrating to solve manually, although the rules are simple.
Click here for Puzzle no. 1.
The aim of the puzzle is to enter a number from 1 through 9 in each
cell of a grid, most frequently a 9×9 grid made up of 3×3 subgrids (called "regions"), starting with various numbers given in some cells (the "givens"). Each row, column and region must contain only one instance of each number. Completing the puzzle requires patience and modest logical ability (although some puzzles can be very difficult).
The program will solve any given configuration of initial clue numbers, provided a solution exists. And it will also tell you (in case you wanted to know) exactly how long it needed to "think." It's pretty fast. Try it!
Right-click game to play full-screen (if available)
Use the cursor keys or the mouse to position the red highlight on the square you want to modify. Press 1-9 to fill the square with that digit or 0 (or SPACE) to erase. The "Clear" button erases the entire board (click on it twice if you wish to remove both a computed solution and the clue numbers).
