Sandwiched Clues
(Published on 5. March 2021, 11:35 by RockyRoer)
The Rules:
- Symbols outside the grid represent clues that must be placed, in order, between the 1's and 9's in that row or column.
- an x separates cells that add up to 10
- a v separates cells that add up to 5
- a * separates cells that have a 2:1 ratio
- a o separates cells that are consecutive (difference of 1)
- a ? must be one of those four, but must be determined by the solver.
- Inside a sandwich, all possible clues are given. No information is implied about cells outside of the 1's and 9's.
- Note: many rows and columns are blank. That's intentional. There aren't any x, v, o or * clues between the 1's and 9's in those rows/columns so that's a big tasty negative constraint to work with.
Some examples:
- A clue of V could be satisfied with ###149### or 172358694
- A clue of Xoo could be satisfied with #182349## but not by #943281## (backwards) nor #1823469# (has extra X)
- A blank clue could be ##1749###, but could not be ##19##### because that would contain an sum of 10 and require an X.
The Puzzle:
Solution code: Row 2, followed by Column 7
Comments
on 23. May 2021, 00:56 by marcmees
Finally found what I was looking for ... and you got the rating as requested.
thanks for a great series.
on 15. May 2021, 09:54 by Nylimb
That took me a very long time. None of the steps were all that hard, but figuring out where I could make progress was difficult from start to finish. Very nice!
on 14. March 2021, 10:39 by henrypijames
I keep wondering why my mind would interpret the rules as 19=blank, and I think it's mainly because when I read the rules, my mind interpret them in a more abstract manner, so "clues ... between the 1s and 9s" was read as "relationship with digits between the 1s and 9s". If instead I had interpreted the rules more visually, that would have been different, and what could have induced a more visual interpretation would be "Clues out side the grid represent symbols that must be placed, in order, onto cell borders between the digits 1 and 9 in that row or column" (switch "clues" and "symbols", as the latter is more visual, and add "onto cell borders").
on 13. March 2021, 19:49 by henrypijames
It was smooth sailing once 19=X has been established. (Of course having spent 10+ hours on it helped...)
on 13. March 2021, 18:26 by RockyRoer
added example
on 13. March 2021, 18:06 by henrypijames
Turn out I didn't understand a 19 sandwich would be an X - I thought it would be a blank. And even now, looking at the rules again, I still find it unclear - the words "between" and "inside" are both ambiguous.
I suggest amending the last example in the rules to make it explicit: A blank clue could be ##1749### but not ##19##### (would be X).
Thanks for the write-up! But I've stopped reading as soon as I got to 19=X. I'm gonna try to solve the puzzle myself now.
Reply: Sorry for the confusion. I had actually considered adding that exact example, but left it out because I wanted the solver to deduce that fact for themselves. But in order to avoid any future confusion, I think it's reasonable to explicitly give that. Good luck on the rest of the solve!
on 12. March 2021, 09:02 by henrypijames
I've worked at this for more than 10 hours in total - and everything I try just breaks. There's something wrong in my logic, and I can't figure out what. Could someone post the solution path please?
Reply: Here's a few steps that may be helpful: shorturl.at/buX57
on 7. March 2021, 18:30 by PixelPlucker
Very challenging for me, but rewarding to work through steadily. Thanks!
on 5. March 2021, 17:40 by Jesper
Very nice. Smooth solve.
on 5. March 2021, 12:17 by RockyRoer
updated solution code
