Website of Gerald M. Berns

Sudoku is a game of logic. The puzzle-solver is presented with a 9 x 9 matrix, some cells of which already contain a non-zero digit. The puzzle-solver solves the puzzle by placing a non-zero digit in each empty cell, such that all the digits 1 – 9 appear in every one of the nine rows, nine columns, and nine 3 x 3 submatrices.

Super SUDOKU is a variant of Sudoku that I developed (others may have done so, too) that places the same requirement on the diagonals: all the digits 1 - 9 must appear in both diagonals, as well as in the nine rows, columns, and submatrices.

It may surprise some to learn that the rules of both Sudoku and Super Sudoku are insufficient to prevent the construction of puzzles that appear solvable but are not. In these impossible puzzles, at some point the puzzle-solver encounters a situation in which no digit can legitimately fit into a cell. My Sudoku program detects impossible puzzles as they are constructed, thereby preventing the puzzle-maker from inadvertently constructing one.

	Click here to download my Sudoku program, which enables the user to solve any Sudoku puzzle and to create his own. It also enables the user to solve and create Super Sudoku puzzles.