Logic Masters Deutschland e.V.

Kropkiominos

(Published on 30. May 2021, 00:17 by zetamath)

0. Normal Sudoku Rules almost apply. Every row and column must contain the digits 1-9 exactly once as usual. However, in lieu of regions, the grid is broken entirely into omino shaped mini-regions, which must be discovered by the solver.

1. Digits may not repeat within an omino, however ominos of size less than 9 will not contain all 9 digits.

2. No two of these ominos have the same shape, including rotation and reflections as the same.  

3. Every omino contains a size clue, either one circle or one square. This cell contains the total number of cells in that omino.  

4. When the size clue is a circle, it gives the additional information that the total of all the cells in that omino is divisible by the size.  When the size clue is given in a square, the sum is not divisible by size.

Kropkiomino clues are given throughout the grid that express certain relationships between two cells:

5. A white kropkiomino clue between two cells indicates that those two cells contain consecutive numbers AND are part of the same omino.

6. A black kropkiomino clue between two cells indicates that those two cells contain numbers that have a ratio of 2:1 AND are part of different ominos.

7. All possible kropkiomino clues are given.  [To say that precisely, every pair of two adjacent consecutive digits which share an omino have a white kropki between them.  Every pair of two adjacent digits with a ratio of two to one that do not share an omino have a black kropki between them.]

Here is an example of a 6x6 grid that has been completed correctly.

Here is an example of a grid where many things have been done incorrectly. [Explanations of each error are given below.]

A) The 2 dominos are the same shape.  No two ominos in the puzzle can have the same shape.  

B) The red pentomino has a repeated 1. Ominos cannot contain repeated digits.

C) There is a white kropki is on the edge of the dark green pentomino. This is not correct. White kropki are always between cells in the same omino.

D) There are an adjacent 1 and 2 within the purple omino. This breaks the negative constraint. If two adjacent digits in the same omino are consecutive, there must be a white kropki between them.

E) Similarly, there is a 2 in purple and a 1 in dark yellow that are adjacent but do not have a black kropki between them, breaking the negative constraint on black kropki.

F) There are four cells that are not part of an omino. Every cell must be part of an omino, even if it is a monomino.

G) The dark blue omino in row one does not contain a circle or square. All ominos contain exactly one circle or exactly one square.

H) There is a black dot entirely within the yellow omino. Black dots only appear between cells in different ominos.

J) The purple omino has a circled 4, but its digits sum to 13, which is not divisible by 4.  In order for this to be acceptable, that circle would have to be a square.

K) The digit in the square of the light yellow omino is not equal to the size of the omino.

Have fun, leave a comment if you enjoy the puzzle!

Play this puzzle on f-puzzles

Solution code: The contents of the ominos that contain these two cells, each read top to bottom, left to right: r2c6 and r8c2. [As an example, in the correct 6x6 grid above, the omino in r5c1 would be 256134.]

Last changed on on 30. May 2021, 13:49

Solved by thetiredsaint, SirWoezel, Jesper, IAM3, Tilberg, henrypijames, harrison, PulverizingPancake, zuzanina, juhish, polar, pandiani42, MagnusJosefsson, wenchang, bernhard, Vebby, soroush, geronimo92, Mark Sweep, DanMeehan, Gnosis66, marcmees, Koalagator, mathpesto, KNT, OGRussHood, StephenR, zhall12570, karlmortenlunna, cdwg2000, Bobbobert, Calesch, h5663454, Niverio
Full list

Comments

on 1. July 2023, 13:08 by karlmortenlunna
Fantastic puzzle!

on 19. May 2023, 20:59 by SudokuLover
f-puzzles is blocked on my computer

on 28. January 2023, 21:09 by StephenR
Great puzzle containing lashings of lovely logic, thanks.

on 30. July 2022, 21:52 by KNT
Criminally undersolved and underrated.

on 1. February 2022, 02:40 by mathpesto
Wow; what a marvelous puzzle! Amazed at how all those properties worked together. Thanks for sending this one my way!

on 11. January 2022, 16:25 by marcmees
amazing puzzle. thanks for all the fun.

on 6. July 2021, 18:16 by Mark Sweep
It's stunning how all rules remain relevant until the end. Great puzzle!

on 8. June 2021, 00:52 by soroush
Brutally hard but no step was impossible. I really enjoyed it.

on 3. June 2021, 16:25 by Vebby
Superb puzzle!! Thank you zetamath!

on 1. June 2021, 21:31 by MagnusJosefsson
Fantastic! Very enjoyable and consistently challenging!

Last changed on 1. June 2021, 12:10

on 1. June 2021, 12:08 by polar
Loved it thank you!

Penpa link (for those that prefer drawing edges in): https://git.io/JGE8T

Last changed on 31. May 2021, 02:32

on 31. May 2021, 00:16 by harrison
@zetamath this puzzle was absolutely lovely. Your Chaos Constructions are such a joy to solve, I look forward to them like I do for @Phistomefel

[Thank you so much, I genuinely cannot think of a bigger compliment to receive than that one!]

on 30. May 2021, 15:35 by Tilberg
Wonderful puzzle, a very satisfying and colorful solve. Thank you!

Last changed on 30. May 2021, 17:10

on 30. May 2021, 14:15 by Jesper
Excellent - that is quite a puzzle! Well worth getting familiar with the ruleset, that looked quite complex at first glance. [I definitely felt like this rule set got away from me a bit, and became more complicated than I like them to be, but I also really liked the puzzle so I posted it anyway, figuring some people might not do it because of the rules, but likely some would enjoy it. -z]

on 30. May 2021, 13:49 by zetamath
[Original version had two digits in the solution code transposed. It has been fixed. Sorry about that!]

Last changed on 30. May 2021, 12:02

on 30. May 2021, 12:02 by Tilberg
F-puzzles says my solution is correct, but it seems I'm too clumsy to fill in the right code ...

Difficulty:5
Rating:97 %
Solved:34 times
Observed:9 times
ID:0006HG

Enter solution

Solution code:

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