Scattered Thunderstorms
(Published on 4. October 2024, 18:18 by bodemeister)
Rules:
- Doppelganger (with an extra twist): Place the digits 0-9 in the 9x9 grid (one digit per cell) so that each row, column, and box is missing one digit from 1-9. Digits may not repeat in any row, column, or box. Digit 0 appears 9 times, and the remaining digits appear 8 times each. For each 0 in the grid, the digit missing in that 0's row and column must be different. Furthermore, the digits missing in a 0's respective row or column must both appear in the bottom right 2x2 corner of that 0's box.
- 1/9 Indexing: If cell (x,y) contains digit 1, then cell (x,1) contains digit y and cell (1,y) contains digit x. If cell (x,y) contains digit 9, then cell (x,9) contains digit y and cell (9,y) contains digit x.
- Each digit on a red line must appear on the other red line.
Solution code: Row 4 of the 9x9 grid (left to right) followed by Column 4 of the 9x9 grid (top to bottom).
Comments
on 6. November 2025, 20:35 by War
I'm trying to tackle this to add to the 2 solves (I've been going back and forth between a few puzzle to keep my logic fresh and not caught in a loop) but considering that the 1/9 indexing is the driver for solving the puzzle (since there are so few other clues) and the interaction between 0s and indexing makes all the logic so much softer(or less forcing), I don't think I have the energy haha. It seems like there has to be a ton of pencil marking and a really sharp eye for catching a hole in the indexing, probably focused on the two red lines' digits or perhaps the 0s.
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This puzzle is very challenging, and both solvers went through quite the war solving it. I could never have set it without first solving and setting other doppelganger and indexing puzzles. And yeah I spent literally an entire one-week holiday setting this. So yeah no shame at all in throwing in the towel on this one. There are better uses of your time! I think you'll enjoy my doppelganger "Does Phistomefel's Ring Still Apply?"
on 27. April 2025, 20:14 by earthpuzzles
This puzzle! The logic always kept me stubbornly hanging on to the path, always feeling like I was one step away from figuring the whole thing out, even/especially when I definitely wasn’t.
I’m glad I can get some rest now, without feeling this unsolved problem tugging at me — the sign of a great puzzle. Thank you!
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Wow what a pleasant surprise to wake up to this morning! Well done solving this animal with no hints whatsoever!
on 15. December 2024, 15:11 by wullemuus
Congratulation to this extraordinary puzzle. Almost no hint and though it could be solved! For I love Doppelgänger puzzles it was a pleasure to bring it together with the indexing ruleset. Maybe you could share with me your logic again ....
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Wow impressive work wullemuus! Thanks for solving this beast. I was worried this puzzle might stay at 0 solves after the first few people who looked at it didn't solve it, but I no longer have to look sadly at the 0 solve number anymore! Sure I'll send some of the key ideas in a hidden comment.
on 5. October 2024, 15:31 by bodemeister
Clarified the rules
on 5. October 2024, 15:04 by andreatetta
Two question about the rules:
1. "Furthermore, a digit missing in a 0's row or column must appear in (here's the extra twist) the bottom right 2x2 corner of that 0's box." Do you mean both digits or at least one?
2.The coordinate (x,y) indicates row x column y?
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1. Both missing digits must appear in the bottom right 2x2 of the 0's box. I'll update the rules for clarity.
2. Yes (x,y) is row x column y.
