HOW ABOUT THE SUPERDOKU WITH ADDITIONAL DIAGONAL AND ANTIDIAGONAL CONTAINING ALL DIGITS?
JOHN MCKAY
These have been around for yonks in the puzzle books as a variation on "number place" puzzles, which is what sudoku is called sometimes. You can certainly have ordinary sudoku completed grids that have this property, one below. I don't know if this is what you meant, but you can also have sudoku puzzles that cannot be done without having this extra piece of information. If you want *all* the diagonals (the pan-diagonals) to have all the digits, then I don't know the answer. Gary McGuire --------------------------------- 492|681|573 357|249|168 816|735|924 ---+---+--- 573|168|492 168|924|357 924|573|816 ---+---+--- 681|492|735 249|357|681 735|816|249