Logic Masters Deutschland e.V.

Black and White

(Published on 12. February 2021, 23:34 by zetamath)

Normal sudoku rules apply.

To complete the puzzle, you must shade some squares. Your shading must satisfy all of the following:

1) All shaded squares are orthogonally connected

2) No 2x2 region is entirely shaded or entirely unshaded

3) No group of unshaded cells is enclosed by shaded cells.  

4) The numbers on the rows and columns indicate the sum of the shaded cells in that row or column.

5) All circled cells are shaded.

6) The digit in a circle matches the number of shaded cells within that box (counting itself).

To clarify, below is a completed grid (for a hypothetical puzzle) that satisfies all of the above rules:

The below grid includes many examples of things that are not allowed.

The things that are wrong are:

In box 1, the circled digit is a 4, but the there are 6 shaded cells.

In box 2, the circled digit is not shaded.

In row 2, the shaded digits do not sum to 18.

In box 4, there is a 2x2 square that is all shaded. Similarly in box 5 there is a 2x2 square that is all unshaded.

In box 6, there is an unshaded region entirely surrounded by shaded cells.

That's all, have fun, leave a comment if you enjoy the puzzle!

Play this puzzle online

Solution code: Row 6 followed by Column 9


Solved by Greg, SirWoezel, Thomster, PixelPlucker, Sktx, polar, EliasKar, stefliew, bigger, kublai, portmanjeau, MagnusJosefsson, StefanSch, tinounou, Quarterthru, Realshaggy, NikolaZ, MalkoMann2, ... wydadman, Xendari, zhergan, St9, StephenR, Kappa6174, widjo, ahmadasiabi, Jodelbanane, SKORP17, Frutlop, karlmortenlunna, Hazem-77, Bobbobert, misko, Carolin, apwelho, Calesch, ManuH, Felis_Timon
Full list

Comments

on 26. November 2022, 22:25 by StephenR
Very enjoyable, thanks.

on 31. July 2022, 10:29 by Christounet
Very subtle and elegant break-in !

on 14. May 2021, 16:16 by BARTE
Great ruleset, great puzzle! Thank you very much for setting such an enjoyable puzzle :)

on 2. May 2021, 15:03 by Mody
Das hat mir sehr gut gefallen, angenehmer Schwierigkeitsgrad und schön logisch lösbar.

on 16. February 2021, 11:42 by StefanSch
Eine phantastische Rätselkombination. Die verschiedenen Elemente greifen bis zum Schuss harmonisch ineinander. Da würde ich gerne 6 Sterne vergeben.

A phantastic puzzle combination. The different parts works harmonically together till the end.
I would like to give you 6 Stars.

That's my puzzle of the month.

on 13. February 2021, 23:02 by EliasKar
I'm not so good at shading puzzles, so that part gave me some trouble, but once I got the hang of it, it was very enjoyable. Amazing puzzle!

on 13. February 2021, 18:12 by PixelPlucker
Very fun solve! The shading component was pleasant and the solution path was incredibly smooth.

on 13. February 2021, 02:18 by Greg
Very nice, good combination of rulesets.

Difficulty:4
Rating:98 %
Solved:75 times
Observed:4 times
ID:0005B4

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Solution code:

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