Taiga
(Eingestellt am 16. Januar 2025, 14:32 Uhr von IcyFruit)
Normal sudoku rules apply.
Identify two "indexer" cells in each row, column, and box, with one indexing in the row and the other indexing in the column. The digit in an indexer cell indicates the position of the other indexer cell in its row or column. Positions are counted left to right in rows and top to bottom in columns.
The value of an indexer cell is the digit in the cell it indexes. For all other cells, their value is their own digit.
All lines are region-subset lines. Box boundaries divide each line into segments. For any pair of segments on the same line, the values on one segment must all appear on the other segment.
Examples
Indexer Cells:
If [] represents an indexer cell, then 12[6]34[7]598 would be a valid row of digits, because there are exactly two indexer cells, and one of the cells indexes the other: the [7] is in position 6, and the other indexer cell contains a 6.
The value of the [6] cell would be 7, because that is the digit in the cell it indexes.
Given that this is a row, we would also know that r7c6 must be an indexer cell, because the [7] cell indexes it.
Region-subset lines:
A region-subset line could contain the values 189-8-98-918, where a dash represents a box boundary. This is valid because [8] is a subset of [89] and [189], [89] is a subset of [189], and [189] is a subset of itself.
Lösungscode: Row 8
Kommentare
am 11. Februar 2025, 21:24 Uhr von OGRussHood
Insane!
am 8. Februar 2025, 14:40 Uhr von sorryimLate
Brutal and brilliant, thanks! My brain was very confused in the world of digits, values, horizontal and vertical, but I don't think the puzzle is ambiguous, nor are the rules. You just need either a lot of patience or a different kind of brain.
SPOILER
@BrianO About your example in box 5: even if you have repeated values on a segment, you still need a certain number of indexer cells on the line, and you can go on solving from there.
am 7. Februar 2025, 15:45 Uhr von BrianO
I intended to solve this, even if it meant working until stuck, watching Simon to get unstuck, repeat...
But: I found at least two big problems that caused me to simply give up.
1) I think the rules are ambiguous about repeated values on a segment. Consider box 5: Could BOTH of the values on the top segment be the same, and match one of the values from the bottom segment? Is that against the subset rules? Simon (and numerous other CtC commenters) seemed to completely ignore this possibilitybut I don't think it's necessarily the case. Both in a rigorous mathematical sense (repeat values are meaningless in set notation), and in a colloquial sense: "All of the values 8 and 8 appear in 1, 8, 9".
2) Unfortunately, I think the solving technology / notation just isn't up to the task. This isn't your fault (or even Sven's), but solving this really demands additional marking modes/options. Note that Simon made multiple incorrect (but lucky!) deductions because of confusion caused by not having enough ways to notate cells.
I think the puzzle is brilliant, but I do think the rules could use a final tweak.
am 6. Februar 2025, 04:18 Uhr von mse326
When I did this puzzle there were a lot of fantastic pieces of logic, but also quite a few places where I felt that my chain reasoning basically was bifurcation. After watching Simon on ctc the same thing. It is certainly possible we both missed some cleaner logic, but that did detract a bit for me. I loved most of the puzzle, and have enjoyed your other puzzles I've done, but this one may have been a bit too hard
am 24. Januar 2025, 15:57 Uhr von Silverstep
Nice sequel to Toutatis! This break-in is deceptively simple...
am 20. Januar 2025, 03:31 Uhr von Klvsched
lil hard
am 20. Januar 2025, 03:31 Uhr von ViKingPrime
Ow, my brain...
am 19. Januar 2025, 19:11 Uhr von henrypijames
I'm sorry, but the indexer example is still not nearly enough for me to understand all of what the indexers do: For instance, I have no idea which part of the rules that bit about "R7C6" is referring to. More importantly, I have many questions about the interaction between one indexer and the three other indexers in its row, column, and box that can only be answered by showing those interactions (I need at least one row and one column intersecting at an indexer, and how that indexer impacts both that row and that column at the same time). Could you provide a visual example, either a complete smaller grid, or a partially filled full grid?
am 19. Januar 2025, 01:20 Uhr von IcyFruit
Added examples
(Sorry this didn't come sooner, I've been ill)
am 18. Januar 2025, 19:28 Uhr von askaksaksask
I find index rules naturally challenging, but this has to be the hardest puzzle I've solved in quite some time. Balancing the indexer cells against the region subsets was far from straightforward, and it took me quite a while to internalize the rules. My solve effort spanned a longer time pondering with no progress than I can remember. Brilliant but devious. The final product is truly beautiful though. Wonderful setting, thank you for this!!
am 17. Januar 2025, 17:03 Uhr von henrypijames
Welcome back.
I don't really understand the rules - there are at least three sentences of the rules whose meaning I'm not certain of. An example would really hhelp - I generally find all indexer rules very hard to understand without examples.
am 16. Januar 2025, 23:25 Uhr von Myxo
Wow! Incredibly hard puzzle, but very very rewarding and brilliantly set.
am 16. Januar 2025, 18:34 Uhr von glum_hippo
Ich finde die Regeln unheimlich verwirrend. Könnte es vielleicht helfen, ein Beispiel zu geben?
I find the rules extremely confusing. Perhaps an example would be helpful?
