Logic Masters Deutschland e.V.

am 15. Januar 2025, 18:21 Uhr von Chilly
Rules update

am 15. Januar 2025, 13:40 Uhr von TheNineElements
@Chilly

Thanks for the info, will be revisiting the puzzle in the coming days to reevaluate it!

The main issue I am/was having is that the solution was being treated as invalid/incorrect because the solve checker wouldn't accept my provided skyscraper clues - even though they are valid. Indeed they aren't required for completing the puzzle, but placing those values doesn't invalidate the solution either - and the solution that sudokupad is referencing for this puzzle is presently invalidating correct solve states.

Here is a link to some screenshots on mobile of the solved puzzle being marked wrong by the sudokupad checker (WARNING SPOILERS):

https://postimg.cc/gallery/tX0jFLm

I recently solved @gdc and @ChinStrap's 'Cagey Architects' puzzle - which has a similar layout with dfog and skyscraper clues. It has several skyscraper cells that aren't necessary for the logic in the solve, similar to this puzzle. They handle these cells by accepting either empty cells (NO placed digit) in those positions OR accepting the CORRECT skyscraper digit being placed in those non-required clue cells. If anything, requiring the correct digits (even if not required for the solve) would be beneficial as it could ensure the solver's logic was valid throughout (and it wasn't a fluke solve - like if they made a non-justified elimination that turned out to be correct). That being said, also permitting empty cells is fine because, as mentioned, they aren't required for the logic.

The 'Cagey Architects' solution check only fails if you place invalid skyscraper numbers into those cells. (For example, placing a '1' in a cell whose first seen digit is a '3' - which must have a skyscraper value of at least '2' - would cause the solution check to fail). It will accept exactly one of the two possible values (empty, or the correcr digit) for any of those outer "non-required" cells.

Additionally, because this is a dFoW puzzle, it isn't clear if there is something hidden under those cells or if we need to place those skyscraper clues to reveal something that is obscured by fog. So the solver cannot know where to place skyscraper clues and where not to. The rules don't specify this, although they probably don't need to if it accepts non-required values.

I think it would be helpful to fix this because it was quite confusing, especially when it was not accepting the solution when every cell was filled.

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Hi - I understand your point, and I checked the gdc and chinstrap puzzle - in fact, they don't accept empty cells - it is necessary to fill in ALL the skyscraper clues around the edge of the grid to get the solution check. If you leave any empty it doesn't work. I also looked at Simon's solve of it, and at the end he had to fill in all the clues he hadn't used. Personally I'm not keen on this since it feels like extra busy work after the main solve is done. However, I also get that you don't want to fill in correct digits and make the solution code fail, so I'll add that to the rules to make sure people are aware that to get the code you need to make sure that there are no skyscraper digits in cells that don't have clues.

am 15. Januar 2025, 08:04 Uhr von Bankey
A bit tedious in the end game but overall a fun puzzle. Thanks, @ Chilly :).

am 14. Januar 2025, 12:17 Uhr von rameshsrivats
Brilliant

am 14. Januar 2025, 08:34 Uhr von TheNineElements
Hi, Chilly. There appears to be an issue with the puzzle currently.

I have placed a valid digit in R2C9 (of the interior sudoku grid, not including skyscraper clue cells). However, the cell with the skyscraper clue on the far right of the second row (the cell immediately to the right of R2C9) has no valid digit that can be placed in it. The puzzle is saying that all values 1-9 are incorrect.

The fog doesn't clear, and after checking every digit 1-9 and checking the solution, none work.

It is possible that I am misunderstanding the rules (or a rule is missing), or that I am having an error locally (on my end), but the puzzle is currently unsolvable for me.

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EDIT:

As I have played around, it appears this issue applies to all of the skyscraper clue cells on the right side of the grid.

I have yet to complete the puzzle (just noticed this in the break-in), but I will continue the solve and see if this is an issue

EDIT 2:

After trying this on a separate device & browser, I can confirm that the puzzle is not recognizing any valid values in the skyscraper clue cells on the far right of the grid

Hi - it is only necessary to enter outside clues when there is a clue in them - e.g. with the Xs or kropki dots that are seen in the break-in. There are no digits in the outside cells where no clues are given, which is why the fog won't clear. It's because those skyscraper clues are not necessary for the solve. In a normal skyscraper puzzle, there are not normally skyscraper clues given for every row and column. Also, bear in mind that dynamic fog does not necessarily get cleared at all, even when a correct digit is placed.

am 14. Januar 2025, 02:33 Uhr von mathpesto
Lots of fun!

am 13. Januar 2025, 19:58 Uhr von Fra314
Beautiful puzzle, great use of the dynamic fog and a grid full of surprises!