All Dots on a Region Border... The 9*9 Sequel
(Published on 3. May 2025, 22:11 by Md88keys)
by Md88keys
Play in Sudokupad
9x9 Chaos Construction rules apply: Divide the grid into nine non-overlapping regions each consisting of nine orthogonally connected cells. Place the digits one to nine once in each row, column, and region.
Kropki Dots: Black dots indicate cells with a 2:1 ratio. White dots indicate cells with consecutive digits.A 1-2 pair could be marked with a white or black dot.
All dots are on region borders. (The two cells connected by a dot are in different regions.)
Negative constraint: All region border dots are given.
Solution code: Column 3 top to bottom
Comments
on 5. May 2025, 17:06 by henrypijames
Must have missed a bunch of stuff, could not do it without heavy bifurcation.
on 5. May 2025, 07:22 by Md88keys
Yes, the intention is to have no given dots within a region, and all possible dots given on region borders
on 5. May 2025, 06:23 by priyanshu1994
I'm pretty sure I'm overthinking, but according to the rules, the negative constraint is only regarding dots on region borders, right? We can still have orthogonally connected cells that satisfy black/white dots within a region, without a dot present in the grid, is that correct?
on 4. May 2025, 23:42 by wuc
140 minutes wow. Very difficult region deductions. From the middle about 3* smooth cc puzzle. The first half is 5* to me. Great fun challenge thx.
on 4. May 2025, 21:43 by Snookerfan
Lovely puzzle! The hardest region building I have ever seen in a CC. The negative constraint worked really well in the endsolve. Thank you
