Logic Masters Deutschland e.V.

Anti-sudoku puzzle #2

(Published on 2. February 2020, 23:58 by Nylimb)

This is the opposite of a sudoku puzzle:

Put a number from 1 to 9 in each cell so that in each row, column, and 3x3 box no number occurs exactly once. I.e. if a number occurs at all, it must occur at least twice.

This puzzle seems to be slightly harder than Anti-sudoku puzzle #1.

I created most of the puzzle by hand, but used a computer program that I wrote to explore ways to finish it.

The puzzle is available on Penpa.

Solution code: Column 4 and column 6.

Last changed on on 22. October 2020, 23:40

Solved by cdwg2000, Alex, ManuH, sf2l, ch1983, zorant, marcmees, adam001, r45, Julianl, Nothere, DocLogic, Uhu, Phistomefel, Ragna, Statistica, Rollo, jessica6, Matt, HaSe, tuace, zuzanina, Mody, Sango, AnnaTh, ropeko, pokerke, cornuto, Realshaggy, KlausRG, rimodech, pin7guin, Ours brun, ildiko, NikolaZ, moss, Lara Croft, ffricke, polar, jwmpuz, drolli38, HawkAvatar, Voyager, Vebby, Mark Sweep, creo
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Comments

on 22. October 2020, 23:40 by Nylimb
Added Penpa link.

on 17. February 2020, 06:53 by Nylimb
Improved terminology; added difficulty comment.

on 4. February 2020, 22:18 by Ragna
Vielen Dank für alle Hilfe!
Sehr kniffelig :-)

Last changed on 4. February 2020, 10:43

on 4. February 2020, 07:16 by Nylimb
@cdwg2000: True. In fact, it's possible for only 1 or 2 numbers to appear in a row, column, or box. But I haven't managed to make a good puzzle in which that happens.

on 4. February 2020, 07:12 by cdwg2000
Note: Only 3 numbers may appear in the row / column / 3 * 3 area!!!

on 4. February 2020, 07:03 by Nylimb
@Ragna: If you'll post a hidden comment describing what you've figured out, I'll try to think of a hint for you that I can put in a public comment.

on 4. February 2020, 04:34 by r45
@Ragna: Vielleicht einfach nochmal die Regeln lesen, es gibt ja verschiedene Möglichkeiten für die Anzahl verschiedener Ziffern in einer Zeile, einer Spalte oder einem 3x3-Gebiet.

on 4. February 2020, 00:13 by Ragna
Ich kriege die Sache mit den
9en nicht hin.
Hat jemand einen Tipp für mich?

on 3. February 2020, 15:47 by marcmees
more tricky than the first one

Difficulty:3
Rating:90 %
Solved:46 times
Observed:5 times
ID:00037B

Puzzle variant Computer assistance

Enter solution

Solution code:

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