VariantDoku Daily Puzzle: May 28
(Published on 28. May 2026, 10:39 by Brandy New)
Normal sudoku rules apply. Place the digits 1-6 once each in every row, column, and 2x3 box.
Kropki: digits separated by a white dot are consecutive; digits separated by a black dot are in a 1:2 ratio (i.e. one digit is double the other).
No Short Index Loops: a cell in row r, column c containing digit d points to row c, column d. A cell may not point to itself, and two cells may not point to each other.
Solve in VariantDoku (iOS) or on SudokuPad.
I would also appreciate feedback on the “No Short Index Loops” rule. Did the rule feel clear from the wording, and was it enjoyable as a constraint, or did it feel too abstract/technical for this kind of daily puzzle? Any suggestions for a clearer wording or better presentation are very welcome.
Solution code: Enter the digits of row 6.
Comments
yesterday, 16:34 by Brandy New
While the global implications sound complicated (like cycles in graph theory), they actually translate into two incredibly simple rules of thumb that let you make immediate pencil marks on the grid.
Here is a quick cheat sheet to get you started:
1. The Diagonal Rule (No Self-Loops)
A cell on the main diagonal (where row number equals column number) cannot contain its own digit.
For example, on a 4x4 grid: R1C1 cannot be 1, R2C2 cannot be 2, R3C3 cannot be 3, and R4C4 cannot be 4.
You can immediately cross those digits off as possibilities for those diagonal cells before you even start!
2. The Partner Rule (No 2-Cell Loops)
For any pair of cells that are symmetric across the main diagonal (like R1C2 and R2C1): if one cell contains the other's column index, the other cell cannot contain its partner's column index.
More simply: If R1C2 contains 1, then R2C1 cannot contain 2.
If R2C4 contains 2, then R4C2 cannot contain 4.
If R3C1 contains 3, then R1C3 cannot contain 1.
yesterday, 02:25 by mellowrobinson
I haven't tried this puzzle yet, the 4x4 the other day took me quite a while, so I'm a little afraid of it lol. It felt like there were some global implications that I didn't understand. As for the wording of the rule: I think you could omit "row r", as the row number is irrelevant to the pointed to cell (unless I'm totally misunderstanding). "A digit D in column C points to row C column D" or something like that I think would suffice.
on 28. May 2026, 12:33 by Brandy New
"The cell in RrCc that has digit d doesn't set any constraint to whatever comes into cell RcCd, unless a case it would be invalid for two different cells is that r=d AND RrCc = d AND RcCd = c (for example: R2C3 = 2 pointing to R3C2 & R3C2 = 3 pointing to R2C3, with r=d=2, c=3)."
on 28. May 2026, 11:06 by Mizuki
I need an example for the no short index loop rule. I don‘t realy get it.
on 28. May 2026, 11:03 by Mizuki
I need an example for the no short index loop rule. I don‘t realy get it.
