Double Dutch Sudoku Advent (21) - Consecutive vs. Slot Machine
(Published on 21. December 2014, 12:00 by Richard)
Eisbär (Arvid) and I have created a fresh sudoku advent calendar in which we combine a well known variant with a relatively unknown variant every day. Combining variants leads to interesting and surprising new solving techniques.
Logically solvable
All puzzles can be solved completely logically although the logic is sometimes well hidden and is inherent to the combination of restrictions that the different types offer. For that reason we have written some solving hints for most of the puzzles, published in a very tiny font. If you want to read the hints, simply copy these in a text editor and enlarge the font size.
Consecutive
Place the digits from 1 to 9 in every row, column and 3x3-block. In all cases where two neighbouring cells contain consecutive digits, a circle is placed between those cells.
Slot Machine
The three shaded columns are like the rolls on a slot machine. The 9 numbers they contain have to be in exactly the same order, taking into account that they wrap around the grid from top to bottom.
Solving hints
Series of 4 consecutives in R4567C9 must contain 6
6 in R8 locked in R8C78 (not in R8C6 since it blocks the possibility for 9 in R8)
6 in C9 in R456C9
9 in C9 in R1C9
R456C9 cannot be {456}; in that case R456C7 = {123} and R456C8 = {789}. This is not allowed since there is no dot in R456C8. :=> R7C9 not 3.
R89C9 = pair {13}; R47C9 = pair {58}; R56C9 = pair {67}; R2C9 = 4
R456C7 must contain 3.
3 in Block top right in R1C8
R9C8 cannot be 4 because the slot machine bands in C2 and C5 contain no dot.
R9C8 = 5 or 7. :=> 6 in R8 in R8C7.
7 in R8 cannot be in R8C8, R8C6. Also not in R8C5 since there are no possibilities for 9 in R8.
R8C2 = 8, R8C13 = {79}; 2 in R8 in R8C56. R8C8 = 4; R9C8 = 7; R8C9 = 1; R9C9 = 3
Solution code: Row 4, followed by row 6.
Comments
on 8. September 2025, 01:54 by ZornsLemon
Very nice puzzle!
On my second pass through on this I actually completely forgot about the slot machine constraint and found I was able to solve it faster without getting sidetracked by that. Just curious if it was meant to be a red herring. Also, if you weren't aware it could be solved with just the consecutive constraint, I'd be happy to post the solve path.
Btw, I'm currently working through all your SVS puzzles. I think I've done all the 4 and 5 star and am working through the 3 star puzzles now. Every one so far has been absolutely fantastic!
---
Reply: First of all: sorry for a late reply. I was on holiday and came back only yesterday.
Thanks for your observation. It is interesting that for this ancient puzzle you seem to be the first to notice this. :)
I am pretty much an expert in consecutive sudokus, so I will definitely want to solve it now using only one constraint.
And yes: I noticed you are working through SVS, and your preference for the harder ones. Keep going, there are plenty more pearls to discover. :)
---
Second reply: you were absolutely right that this one can be solved without the slot machine constraint. It was an interesting solve path with some tiny elominating steps that were yet very powerful. Once more thanks for pointing that out!
on 11. April 2022, 16:39 by Nick Smirnov
F-puzzles:
https://f-puzzles.com/?id=yb2dtkq9
CTC App:
https://tinyurl.com/yckjftpd
