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.
Lösungscode: Column 4 and column 6.
am 22. Oktober 2020, 23:40 Uhr von Nylimb
Added Penpa link.
am 17. Februar 2020, 06:53 Uhr von Nylimb
Improved terminology; added difficulty comment.
am 4. Februar 2020, 22:18 Uhr von Ragna
Vielen Dank für alle Hilfe!
Sehr kniffelig :-)
am 4. Februar 2020, 07:16 Uhr von 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.
am 4. Februar 2020, 07:12 Uhr von cdwg2000
Note: Only 3 numbers may appear in the row / column / 3 * 3 area!!!
am 4. Februar 2020, 07:03 Uhr von 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.
am 4. Februar 2020, 04:34 Uhr von 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.
am 4. Februar 2020, 00:13 Uhr von Ragna
Ich kriege die Sache mit den
9en nicht hin.
Hat jemand einen Tipp für mich?
am 3. Februar 2020, 15:47 Uhr von marcmees
more tricky than the first one