Easy Peasy Sudoku Advent (11) - Killer Skyscrapers
(Published on 11. December 2025, 06:00 by Richard)
This sudoku advent calendar contains 24 variants that were included in my Sudoku Variants Series (SVS) but turned out to be too hard to be solved by a wide range of puzzlers. I aim for difficulties of 1-2 stars and have written some general and/or specific hints as well. I hope some players will try the original SVS puzzle #300 after solving the advent version.
Killer Skyscrapers
General hint for this type:
A cage with a sum of 3 that has one digit in the grid and one digit outside the grid must have the 1 in the grid, immediately followed by a 9.
Apply classic sudoku rules.
Each digit within the 9x9 region represents a skyscraper of that height. Digits outside this region indicate how many buildings can be seen from that direction, where higher buildings block the view of lower buildings. The small numbers in the upper left corner of a cage indicate the sum of the digits in that cage. Within a cage all digits must be different.
If a cage that is completely outside the grid contains a 1, you can pencilmark the cells that must contain a 9 on the other side of the line.
Solution code: Column 4 (9 digits)
Comments
on 23. December 2025, 01:13 by Reina
Fenomenal!
on 21. December 2025, 02:23 by SennyK
Another very clever puzzle, thank you!
on 12. December 2025, 01:24 by abihummel
I broke this one quite a few times before figuring it out. But I am determined to complete every puzzle in this series! They are often right on the edge of what is doable for me! :)
on 11. December 2025, 23:25 by VitP
this is going to be quite difficult for beginners ... mostly because you can search and search, and not get to the key (which is in box 1, after completing the easy part) before giving up hope.
on 11. December 2025, 22:02 by VitP
in Muenchen steht ein Hochbraeuhaus ...
on 11. December 2025, 21:34 by Snaques
I liked the puzzle, but on Sudokupad it could work better.
The solution check doesn't work and the skyscraper clues show as normal sudoku digits, meaning if there is a 1 in the skyscraper clue it says that there can't be another 1 in that row/column.
Maybe this helper function can be disabled, but I don't really see it adding value to the logic of the solve on any other puzzle so I like to keep it on.
on 11. December 2025, 13:08 by Br1312te
Sudokupad doesn't register it as finished (I think this is also what Fisherman is talking about), but great puzzle nonetheless!
on 11. December 2025, 09:21 by Platinum
Lovely puzzle
on 11. December 2025, 08:59 by Fisherman
Great and courageous puzzle. However, I was unable to get to the heart symbol of sudokupad. I want to click that heart red, desperately.
---
Hi Fisherman, to be honest, I really don't know what you are talking about. :)
But if the heart is meant to express that you are grateful, or liked the puzzle, then your written comment is received in good order, accepted and much appreciated. :)
(And it means more to me than a digital heart.)
on 11. December 2025, 08:25 by Klausku
I should do skyscrapers more often, they are always twisting my brain. This one was nice and easy. Thanks.
on 11. December 2025, 06:24 by Piatato
Super smooth!
