This sudoku advent calendar contains 24 variants that were included in my Sudoku Variants Series (SVS) but turned out to be too hard to be solved by a wide range of puzzlers. I aim for difficulties of 1-2 stars and have written some general and/or specific hints as well. I hope some players will try the original SVS puzzle after solving the advent version.
Killer Kropki
Specific hint for this puzzle:
The black dots in box 5 force a chain of doubling sums. There is only one possibility for that: 2, 4, 8, 16.
Apply classic sudoku rules.
A white dot between two dotted outlined regions indicates that the sums within those regions have a difference of one. A black dot between two such regions indicates that one of the sums is twice the other sum. When there is no dot between two regions, they cannot have sums that differ by one or are double. Digits may not be repeated in regions.
Use the fact that all cage-relations are given!
Solution code: Row 8
today, 00:42 by iffy
Didn’t notice the negative constraint until the very end. I wonder if it would have been an easier solve if I’d used it. Still a fun puzzle tho!
yesterday, 21:54 by walid_tun
fun really
yesterday, 20:01 by dzamie
The logic required is pretty easy to figure out - it's just a matter of execution, which is a bit tricky. The negative constraint is also a really cool addition!
yesterday, 18:52 by Richard
Repaired a missing dot in R1 in the image and both online solve links.
My apologies...
Thx Rollo for pointing out!
yesterday, 16:23 by flutchman
Fun indeed. I'm having a jolly good Advent time. Thanks Richard.
yesterday, 08:24 by Piatato
Fun!