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Feedback and Questions

I've received a lot of interesting comments and questions from Sudoku fans over the last few years and this page is where I try to answer them. I'm also directing Str8ts feedback here. Please feel free to drop me a note on the side of the page. Or you can email me directly at andrew@str8ts.com.

Post a Comment or Question here...

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Any Sudoku you want to publish here for easy loading into the solver - 81 characters, use '.' or '0' for unknowns.

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Comment, question or feedback:

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If you are writing to alert me of a problem (thank-you!) please include a url to the page in question.
Can get fixes in quicker if I know immediately where to go.

Many thanks to all the people who have helped improve the solvers and strategies with their feedback!

Saturday 16-Mar-2024

... by: Chris B, Canada

I noticed today that the Ipad and Iphone buttons are missing from the Daily Sudoku (present for Str8ts). Is that intentional? Thanks!

Andrew Stuart writes:

Still there, just scroll down a bit more, under the player

Monday 4-Mar-2024

... by: Jan, Den,ark

Hi,
First thank you for this amazing sudoku-solver!
Is it possible to type in the shape of the jigsaw sudoku? The site has a limited number of predefined shapes that does’nt match my jigsaw for which I need help. I imagine that I type 1 to 9 repeating the same number identifying each box shape.
Regards
Jan

Andrew Stuart writes:

Almost top of my job list. I need a way of getting the shapes into the server side solver. But certainly possible I'm sure

Wednesday 28-Feb-2024

... by: World, USA

Load Sudoku: CLICK TO LOAD

Not sure if this is a bug but using your solver on this sudoku produces a peculiar result. When you get to the hidden triple in Box 7 (126) and Column 1 (156), the Box 7 hidden triple eliminates 5 from J1 but then the 5 is added back since it is part of the hidden triple in Column 1.

Andrew Stuart writes:

I think you might have stumbled across something funny going on there. The solver allows all hidden pairs and triples to apply in one step but long ago I wrote the code to not implement the eliminations until after all were assessed. This is to avoid cascading effects which would be hard to trace. However in this instance part of a hidden triple was a number which was previously flagged as eliminated - but not invalidating the following triple. I've changed it now to preserve the elimination in this case. Subtle and rare but nice to get

Thursday 22-Feb-2024

... by: Peter O, Germany

A super website

Andrew Stuart writes:

Thanks!

Monday 19-Feb-2024

... by: Lorna, England

Is it possible to create a new jigsaw sudoku in the jigsaw solver in the same way that a new killer sudoku can be created, as the jigsaw designs listed do not match the designs in the magazine I have.

Andrew Stuart writes:

I really hope to provide this soon. I need a way to pass an arbitrary map into the solver. Is near the top of my wish list for sure

Friday 16-Feb-2024

... by: Klemens Mevenkamp, Germany

Found a bug in the jigsaw solver. After elimination with the simple strategies it finds a rectangle elimination saying B1+2 forces A3+2, which is correct, but that means two 2s in box 1, not none.

Andrew Stuart writes:

Send in the example! Would love to make a correction to the solver for this situation

Wednesday 7-Feb-2024

... by: Fred Harte, Ireland

Load Sudoku: CLICK TO LOAD

A Penguin Pocket book contains 201 classic puzzles of which just one seems to have more than one solution according to your solver. I don't know whether this oddity is due to a misprint in the book or to a bug in the solver. I have given it here so that you can decide if it is the latter.

Andrew Stuart writes:

Check you entered the numbers right into the solver. Could be a typo there or a missing clue
If all correct, then 100% confident that is a badly made Sudoku puzzle. While it's quite easy to make a puzzle, checking it has one solution is a lot harder. Looks like they skimped!

Friday 19-Jan-2024

... by: Fanou, France

Bonjour,
Lorsque je coche "effacement automatique des candidats", la saisie d'une solution de cellule recalcule tous les candidats et les affiche, même ceux effacés volontairement (suite à la détection de paire par exemple ).
Il faut alors re-effacer les candidats inutiles détectés aux étapes précédentes. C'est dommage !
Est il possible de remédier à ce problème?
Merci d'avance.
Cordialement

Andrew Stuart writes:

You need to turn off "auto clear". But "Take Step" will re-calculate. I suggest using the "Player >" button to take the puzzle to the player since that is where you can complete the puzzle manually, or stay in the solver and don't use "Take step". I don’t think it is possible to add candidates that the solver disagrees with. Hope that helps a bit

Wednesday 10-Jan-2024

... by: AnnEliza, Canada

Lettericious isn’t working it’s doubling or tripling the scores

Andrew Stuart writes:

Yes I’ve been trying to figure out why and no luck so far. I have created a system where I can re-calculate the score and overwrite, which I have done. I am checking everyday. I am probably going to have to re-write the scoring part.

Saturday 6-Jan-2024

... by: Carl, Southern California, USA

Is there a key to decoding your annotation system ?

Andrew Stuart writes:

Do you mean the longer Sudoku string format?
There is an explanation and code here

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Thank-you everyone for all your questions and contributions.