- Code: Select all
`. . . | . . 1 | . . .`

. 2 . | . 7 . | . 3 .

. . 4 | . . . | 2 . .

------+-------+------

8 . . | 5 . 6 | . . 2

. . . | . 1 . | . . .

1 . . | 4 . 7 | . . 9

------+-------+------

. . 3 | . . . | 1 . .

. 4 . | . 5 . | . 6 .

. . . | 9 . . | . . .

Each cell in this Sudoku is a member of FOUR groups rather than the normal THREE (rows, columns and 3x3 boxes). The fourth groups are:

- Code: Select all
`a b c | a b c | a b c`

d e f | d e f | d e f

g h i | g h i | g h i

------+-------+------

a b c | a b c | a b c

d e f | d e f | d e f

g h i | g h i | g h i

------+-------+------

a b c | a b c | a b c

d e f | d e f | d e f

g h i | g h i | g h i

(To be clear, no two cells with the same letter will contain the same digit in the solution.)

You'll have to solve this one on paper, as Pappocom's software won't let you work on puzzles that are unverifiable. Actually, nearly every other Sudoku application available WILL let you load this to solve on your own.

You can try here:

http://www.scanraid.com/sudoku.htm?bd=000001000020070030004000200800506002000010000100407009003000100040050060000900000

This is one of many variations common in several Japanese Number Place magazines. They're printed in color, with each cell in the same disjoint group sharing the same color.

The solution is below:

- Code: Select all
`3 8 9 | 2 4 1 | 6 7 5`

5 2 1 | 6 7 9 | 8 3 4

6 7 4 | 8 3 5 | 2 9 1

------+-------+------

8 3 7 | 5 9 6 | 4 1 2

4 9 5 | 3 1 2 | 7 8 6

1 6 2 | 4 8 7 | 3 5 9

------+-------+------

9 5 3 | 7 6 4 | 1 2 8

2 4 8 | 1 5 3 | 9 6 7

7 1 6 | 9 2 8 | 5 4 3