Sudoku Variants Series (438) - Regular Dots
(Published on 22. August 2025, 06:00 by Richard)
This puzzle uses the same ruleset as SVS #422, but now it is in a standard 3x3-grid. SVS #422 turned out to be solvable without the negative constraint, but for this one, the negative constraint is definitely necessary in your solve.
Regular Dots
Inspiration for this type comes from WSC2024.
Solve online in Sudokupad.
Apply classic sudoku rules.
All adjacent cells that contain digits with a difference or a sum equal to the index number of the column or row are marked with a white dot (difference) or a black dot (sum).
Solution code: Column 2
Comments
on 26. August 2025, 23:07 by dzamie
Remarkably much easier than this series usually has, or maybe I just had an easy time keeping the negative constraint in mind. That always provides a fun extra set of clues to a puzzle.
Though it did take me a bit to remember which dot was which operation.
on 25. August 2025, 21:12 by Mouser1299
Tried this yesterday and completely forgot about the negative constraint!
on 24. August 2025, 06:21 by Richard
Added missing dot in SudokuPad link.
on 22. August 2025, 22:34 by Piatato
The negative constraint played into the solve very nicely, thanks!
on 22. August 2025, 21:30 by Lizzy01
3 stars for me.
on 22. August 2025, 17:33 by Franjo
That missing white dot in the SudokuPad-version (c5r2,3) nearly left me lost in desperation! ;-)
Apart from this I really enjoyed another nice and approachable episode of the series. Thank you very much for creating and sharing another lovely puzzle.
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Reply: oops! Sorry for that. That was exactly the feedback from my test solver (rcg) too; I changed it, but took the old link by accident. It is fixed now.
