Logic Masters Deutschland e.V.

Coprime Directive

(Published on 12. March 2021, 07:20 by cristophermoore)

Sudoku rules apply. A white dot between two digits indicates that they have a common divisor greater than 1, such as 4 and 8 or 6 and 9. The negative constraint applies: a pair of digits without a dot are coprime (also called relatively or mutually prime) with 1 their only common divisor, such as 6 and 7 or 3 and 8.

A gray square in a cell indicates a primesweeper constraint: the digit there equals the number of primes (2, 3, 5, or 7) that appear in the 3x3 neighborhood centered on that cell, including the cell itself. All possible gray squares are given, so negative constraints apply.

f-puzzle link (note f-puzzle will not enforce the coprime or primesweeper constraints).

Solution code: Row 1 of the solution

Last changed on on 18. March 2021, 01:32

Solved by kroutu, Arashdeep Singh, loscpi, Mesmer, karen_birgitta, henrypijames, LeLoyJenkins, bigger, nordloc, Timwi, JamesH, galgamer, ashwin, Pignut, KyubiBoy, sandmoppe, Kormi
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Comments

on 19. April 2023, 20:59 by Pignut
Very nice puzzle, I really got the hang of this ruleset!

on 18. March 2021, 01:32 by cristophermoore
added Primesweeper tag

on 13. March 2021, 07:24 by cristophermoore
added German tag for coprime

on 12. March 2021, 19:44 by Arashdeep Singh
Great puzzle. :)

on 12. March 2021, 19:12 by cristophermoore
Kein Problem!

on 12. March 2021, 19:05 by SKORP17
ok, ist klar (sorry, das habe ich zunächst falsch verstanden)

on 12. March 2021, 19:01 by cristophermoore
Ja, aber die grauen Zellen sind diejenigen, deren Anzahl gleich der Anzahl der Primzahlen in ihrem 9-er Umfeld ist. In diesem Beispiel gibt es 5. (Die 5 erscheint zweimal.) Hilft das?(Entschuldigung für mein Deutsch.)

Last changed on 12. March 2021, 18:55

on 12. March 2021, 18:54 by SKORP17
Das habe ich ja auch so verstanden, aber ich verstehe den Sinn dieser Zellen nicht. Jede Zelle hat in ihrem 9-er Umfeld Primzahlen, oder geht es nur um die 7 Zellen, die auf dieser Diagonale liegen?

Last changed on 12. March 2021, 18:47

on 12. March 2021, 18:46 by cristophermoore
Die grauen Zellen beziehen sich auf die 9 darauf zentrierten Zellen. Hier ist ein Beispiel:
https://f-puzzles.com/?id=yjsh3a8v

on 12. March 2021, 08:03 by cristophermoore
I think the hardness is 3/5 rather than 4, but your mileage may vary

Difficulty:4
Rating:93 %
Solved:17 times
Observed:10 times
ID:0005O4

Puzzle variant Arithmetic puzzle

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Solution code:

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