alte karte / ferneiland
(Published on 14. November 2025, 02:34 by aqjhs)
So ChinStrap suggested to me this concept for a doppelgänger puzzle, I hope you like the take on it.
- Doppelgänger Sudoku:
- In the 9x9 grid, every row, column, and box contains a 0 always, as well as eight out of the nine digits from 1 to 9 (ie, it's missing one digit)
- No two row, no two column, and no two box may be missing the same digit
- For each 0 in the grid, the digits missing in its row, its column, and its box must be three different digits.
- Fill the cells outside the 9x9 grid with the digit missing from the corresponding row, column or box.
-
Skyscraper Arrows:
- The value of an arrow in a cell is equal to the digit in the cell.
- The value of an arrow outside the grid and note space is equal to the missing digit in the corresponding row or column.
- The value of an arrow indicates the number of digits seen in that direction, for that effect, digits block any lower or equal digit from being seen.
- Zero (0) is never seen.
- Non cell spaces block sight and are never seen.
On theme:
Solution code: Digits on the column missing an 8, top to bottom.
Comments
on 12. January 2026, 12:24 by wullemuus
Once I?ve understood the logic of the arrows just outside the grid the break-in was very elegant. The mid-solve was intricate- maybe you would share the intended solving path in a hidden comment? I'm always curious to understand the inner logic better ... .
on 6. December 2025, 02:21 by SennyK
Masterpiece!
on 18. November 2025, 09:29 by kodra22
This took me 2.5 hours
on 17. November 2025, 16:57 by War
Excellent puzzle!
on 15. November 2025, 05:13 by aqjhs
clarification: non cell spaces block sight and are never seen.
on 14. November 2025, 05:35 by bansalsaab
Hi, can the inside arrow skyscrapers see outside the grid and note space?
***
No, the non-cell spaces block sight, even if they have arrows.
