For fans of Killer Sudoku, Samurai Sudoku and other variants

help me solve this puzzel for my kid

it's a 7 x 7 square and you have to use the numbers from 1 to 7 and the same number should not come twice in the same line, diagonaal and column.

1 . . . . . .
. . . . . . 3
. . . . 4 . .
. . 5 . . . .
. . . 2 . . .
. . . . . 7 .
. 6 . . . . .

Thank you
twerkman

Posts: 2
Joined: 17 March 2013

I added an attachment in word, more easy to fill.

Thanks
Attachments
7x7.docx
twerkman

Posts: 2
Joined: 17 March 2013

### 7x7 Latin Square X puzzle

multiple solutions ..... That means that you can solve this puzzle with the constraints you mentioned but that solution is not unique.

tarek

Posts: 3759
Joined: 05 January 2006

### Re: 7x7 Latin Square X puzzle

Any time you try a puzzle from an unknown source, and naively assume uniqueness, if it seems to be an unusually difficult puzzle, it's probably because you've solved as much as can be solved, with multiple possibilities for most or all of the remaining cells. Beware!

Bill Smythe
Smythe Dakota

Posts: 564
Joined: 11 February 2006

twerkman wrote:

it's a 7 x 7 square

you have to use the numbers from 1 to 7

the same number should not come twice in the same
• row
• diagonaal
• column
Code: Select all
`1 . . . . . .. . . . . . 3. . . . 4 . .. . 5 . . . .. . . 2 . . .. . . . . 7 .. 6 . . . . .`

We think that there is a fault somewhere....

= jigsaw boxes

Pat

Posts: 3968
Joined: 18 July 2005

### Re:

If "diagonal" was intended to mean "any diagonal", not just the main diagonals, then there is just one solution.

If the diagonals are the "extended" kind (with length=7), then the puzzle can be solved easily with triples & pairs. If they're the "short" diagonals, with the only the requirement that no number appears twice, then it's much harder to solve, but there's still only one solution.

Actually any filled grid (against an empty clue set) that satisfies the "short diagonals" condition, also has no matches (and so all 7 numbers) on the extended diagonals. I don't know if that's easily proved or not.

Blue.
blue

Posts: 909
Joined: 11 March 2013

Perhaps a proof by induction starting with a 3*3?
HATMAN

Posts: 276
Joined: 25 February 2006
Location: Saudi Arabia

Brilliant Blue ....

However

These puzzles should be designed as a toroid and therefore a square puzzle with lines having an even number of cells would have been more aesthetically pleasing because you you can leave the diagonals open ended and successfully form the toroidal puzzle. (This comes from work done on the Fairy chess puzzles )

tarek

Posts: 3759
Joined: 05 January 2006