The New Sudoku Players' Forum

[Botchee]

Oh yes ... the non-unique solution haunts me to this day as something discovered to late. Having hired someone to code a new shape of Sudoku, I was excited to pay the guy for what I thought was excellent work. Having paid and exchanged excellent ratings on rentacoder we each went our separate ways. Only later did I discover my lack of due diligence, and there was no recourse or help available, as the coder went unresponsive and I tired of daily checks and fixes of the generated puzzles.

Turns out the new (24 tiles or cells as you call them here) shape wasn't that challenging when solved like a standard Sudoku. Years later I have began to revive the idea as an interactive game, but that is a tale for another thread. You may experience the original flawed program at http://TopHatSudoku.com

The practice puzzles all have unique solutions and a printout is available at http://Botchee.com

This site looks great, and I will post more once I've had a chance to look around

[999_Springs]

i got bored and went to sudoku.com for the first time ever. the very first puzzle they gave me was this

multiple solution sudoku.png (241.95 KiB) Viewed 4169 times

[Pat]

seems systematic,
sudoku.com "Expert" level
removes too many givens
(always leaving 15, cute)


now also discussed on other forum
EDIT: but, did they ever promise exactly-1-answer ?
apparently not,
so we have no right to complain---

[Pat]

www.goplaysudoku.com
-- more than one answer


(see discussion)
but, they never promised exactly-1-answer

[ghfick]

sysudoku.com/2012/01/03/aligned-pair-exclusion-ape/

The 'published' puzzle does indeed have multiple solutions. I suggest, in my response, that the trouble is a typographical one. I wonder how often this is the real issue in published puzzles.

Gordon

[enxio27]

The 'published' puzzle does indeed have multiple solutions. I suggest, in my response, that the trouble is a typographical one. I wonder how often this is the real issue in published puzzles.

I doubt it. Far too many people who fancied themselves programmers jumped on the sudoku bandwagon when it got popular, even though they themselves had no clue about what a sudoku puzzle should look like or how they are constructed. As a result, there are/were many sites and apps out there that generate sudoku-like objects that don't qualify as real sudoku. Witness the number of pages in this thread, all containing invalid puzzles or sites that produce invalid puzzles.

[doug9694]

I started working on solving the 1465 #77. Found on this site evidence of multiple solutions that should have put this puzzle In this thread back in 2006.
Instead, there was thread after thread of ways too solve this bogus puzzle. Did they not have a good way of determining un-uniqueness in 2006-8?
Then, as someone commented in 2009, that interest in this puzzle dropped. No reason given.

7.....4...2..7..8...3..8..9...5..3...6..2..9...1..7..6...3..9...3..4..6...9..1..5 SER 9.8
from the Top 1465 list
the-toughest-known-puzzle-t3827-15.html

+-------+-------+-------+
| 7 9 8 | 6 3 5 | 4 2 1 | Two solutotions??
| 1 2 6 | 9 7 4 | 5 8 3 | Postby keith » Tue May 30, 2006 9:14 pm
| 4 5 3 | 2 1 8 | 6 7 9 |
+-------+-------+-------+
| 9 7 2 | 5 8 6 | 3 1 4 |
| 5 6 4 | 1 2 3 | 8 9 7 |
| 3 8 1 | 4 9 7 | 2 5 6 |
+-------+-------+-------+
| 6 1 7 | 3 5 2 | 9 4 8 |
| 8 3 5 | 7 4 9 | 1 6 2 |
| 2 4 9 | 8 6 1 | 7 3 5 |
+-------+-------+-------+

786 912 453
925 473 681
143 658 729 Postby Alain David » Tue May 30, 2006 8:05 pm
284 596 317
367 124 598
951 837 246
612 385 974
538 749 162
479 261 835

Perhaps no one else saw this "other solution"??

[pjb]

The puzzle has only one solution - the first. The second above has 2 9s in column 1
Phil

[Pat]

The puzzle has only one solution - the first. The second above has 2 9s in column 1

you are amazingly patient

keith (2006.May.30) already said it


doug9694 managed to mis-read the very post from which he quoted

[Leren]

I can't resist this. The bogus solution has two 9's and no 8 in Column 1 and two 8's and no 9 in Column 2. Apart from that all rows, columns and boxes conform, unless I've missed something.

Leren

[Madolite]

I think we should consider deprecating the shame, say after 6 months, or something. Just a suggestion. Cause I think it's easy for these outlets to use bunk sources for their Sudoku, only to realize the mistake after people have complained to them and then improving their papers after. Obviously, if they're repeat offenders, we can put them on permanent shame until they can prove that they're now using a proper, reliable source.

[enxio27]

I think we should consider deprecating the shame, say after 6 months, or something. Just a suggestion. Cause I think it's easy for these outlets to use bunk sources for their Sudoku, only to realize the mistake after people have complained to them and then improving their papers after. Obviously, if they're repeat offenders, we can put them on permanent shame until they can prove that they're now using a proper, reliable source.

Madolite, the vast majority of these publishers (if they're still even publishing sudoku--most are not) don't care. They don't know or care anything about sudoku--they just have space they need to fill, hopefully with something that will catch readers' attention. They also don't know or care about our "Sudokus of Shame" thread here, and probably wouldn't change anything even if they did become aware of it. They certainly aren't getting enough complaints from readers to make it worth their while to care.

Publishers of most sudoku books, apps, etc., also fall into the category of not knowing or caring about "proper" sudoku. They're just trying to make a fast buck, although I can't imagine there is much money anymore in sudoku now that the "craze" has long since worn off. Again, the puzzles these outlets publish are geared toward newbies and dabblers who also don't know anything about "proper" sudoku--their interest is a passing fancy.