Logic Masters Deutschland e.V.

Projective Forbidden Pairs

(Eingestellt am 24. Januar 2021, 12:52 Uhr von LKegel)

Normal sudoku rules do NOT apply. This puzzle takes place on a projective plane (see wikipedia if you're interested). This means that opposing sides of the grid are twisted and then glued together. A blue dot shows where two projective rows are separated, and a red dot shows where two projective columns are separated.

An example of a projective row and column and adjacency on a projective plane (traveling up from R6C2 you end up in R5C8, etc.)


The rules:
- The 3x3 boxes contain the digits 1-9 exactly once as usual.
- Every projective row and column contains the digits 1-9 exactly once.
- Two adjacent cells may not contain the following pairs in any ordering: (1,9), (2,3) and (7,8).

Important: Think carefully about when two cells are adjacent on a projective plane. For example, cells separated by a dot may seem to be adjacent, but they are not! Also, it is fine to break the standard rules of sudoku by having repeats in a standard column or row!

f-puzzles link here: here.

Lösungscode: Column 6 followed by row 5 (of the actual grid, so no projective rows or columns).

Zuletzt geändert am 25. Januar 2021, 09:33 Uhr

Gelöst von SirWoezel, DiMono, Jviscus, bigger, polar
Komplette Liste

Kommentare

am 26. September 2021, 20:40 Uhr von polar
Very nice puzzle but boy did I have to concentrate (and restart a couple of times)! Definitely needed colours on the rows/columns to keep me on track.

Penpa+ link:

https://git.io/JzSjM (no colours)
https://git.io/Jz9em (with colours)

am 25. Januar 2021, 22:15 Uhr von Jviscus
a toughie, but a goodie. well worth the time :)

Zuletzt geändert am 25. Januar 2021, 13:25 Uhr

am 25. Januar 2021, 13:23 Uhr von SirWoezel
If you think this is hard, just wait until setters start combining this ruleset with sandwich sudoku ;)

@SirWoezel Wow that sounds absolutely evil!

am 25. Januar 2021, 09:33 Uhr von LKegel
Added examples of adjacency and changed difficulty to 3/5.

am 25. Januar 2021, 04:11 Uhr von DiMono
I think you have seriously underestimated the difficulty of this puzzle. After almost half an hour I have 6 digits placed. This is easily a 5/5 difficulty.

Zuletzt geändert am 24. Januar 2021, 21:50 Uhr

am 24. Januar 2021, 21:43 Uhr von SirWoezel
Weird. Loads of fun too. But mostly weird.

@SirWoezel I hope that's a compliment ;)

am 24. Januar 2021, 13:58 Uhr von LKegel
Clarified the "forbidden pairs" rule.

am 24. Januar 2021, 13:31 Uhr von LKegel
The example contained an error, this has been fixed.

Schwierigkeit:3
Bewertung:N/A
Gelöst:5 mal
Beobachtet:8 mal
ID:00059L

Rätselvariante Neu

Lösung abgeben

Lösungscode:

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