Mysterious Boxes
(Published on 8. January 2023, 16:19 by fjam)
- Normal Sudoku rules apply.
- A column indexer cell in RxCy containing z places y in RxCz. A row indexer cell in RxCy containing z places x in RzCy.
- In each cage in the grid, one cell is a column indexer and the other is a row indexer. The sum of the digits in the cage is the same as the sum of the indexed digits. Cells in cages may not index themselves or the other cell in their cage.
In this example image, the red cell in R1C1 containing 3 is a column indexer, which means that R1C3 must contain 1. Similarly, the green cell in R3C3 containing 2 is a row indexer, which means that R2C3 must contain 3.
As this puzzle is unusual, some notation advice is available below in white text (highlight to read). This is not a hint, but is provided for any solvers unsure of how to keep track of their deductions.
Corner marking cells in cages with the possible digits that could be indexed from that cell should help. These corner marks can then be deleted from a cell once it is identified as a column/row indexer, when it should be coloured red/green respectively (or some other combination of two colours). Solvers are strongly advised not to colour the cells that are being indexed, just the indexers.
This was the second of two puzzles I constructed for Fahmi Sack in the CTC Discord 2022 Secret Santa. I had not set an indexing puzzle before, but I decided that I would try to do so and come up with something new instead of a 159 Sudoku. After experimenting a bit, I came up with this concept of pairs of indexers in cages with equal sums. I was surprised and delighted to find it was unique with just 10 empty cages, with some innovative logic needed to solve the puzzle.
The first Secret Santa puzzle can be found here: The Holly & The Ivy
Solution code: Row 1, Row 8
Comments
on 25. July 2024, 03:08 by ClashCode
Quite a fun puzzle, some cool interactions :)
on 1. April 2024, 19:16 by dumediat
Something about this just clicked for me, and your note taking suggestion certainly helped. I loved the logic throughout this, very rewarding and fun. Thank you!
on 2. February 2023, 23:22 by stayal
Mind bending ruleset. but it blew my mind that it solved so well once I wrapped my head around the constrictions.
on 29. January 2023, 17:39 by Playmaker6174
Very rewarding and satisfying solve overall! The start wasn't so tricky of a part, but it got significantly harder later on, especially around those cages in row 7 and box 5, but I'm glad that I found the needed things in time before my brain actually melted ;)
on 29. January 2023, 06:59 by zegres
This is a great puzzle!
It is very surprising that it can even exist in such a minimalist way, until you start to understand the constraint.
This puzzle is also very good about teaching this constraint the further you go the more intricate the logic gets and you have to use everything you learned before.
Very cool idea!
on 12. January 2023, 14:38 by mathpesto
A brutal yet rewarding puzzle experience! Took a bit to wrap my head around how to approach this methodically, but very cool ruleset and lots of cool interactions in the grid.
on 12. January 2023, 09:00 by XeonRisq
Brain melting but very fun, and definitely worth the effort to solve. Nice idea, great execution.
on 11. January 2023, 17:35 by Samish
Great ruleset and very impressively minimalist puzzle, it unfolds quite neatly but it was also very hard for me
on 9. January 2023, 18:15 by Bellsita
I really like this type of indexing! Loved that puzzle!
on 9. January 2023, 18:15 by Malrog
Brain bending concept, but very rewarding to puzzle through. Thank you :)
