Summation U-Bahn #4: Skyscrapers
(Published on 30. September 2024, 09:00 by Agent)
It was about time I set another Summation U-Bahn as it very well might be one of my favourite rulesets to set with. I hope you enjoy!
Rules
- Draw a loop network through the centers of some cells, which may branch or turn, but may not have any dead ends.
- Assign each line shape (irrespective of rotation) a digit from 1 to 4 as follows: corner = 1, straight line = 2, branch = 3, cross = 4.
- Summation U-Bahn clues indicate the sum of "digits" in each contiguous sequence of cells visited by the loop network, in the correct order. Consecutive sequences must be separated by at least one cell not visited by the loop network.
- Skyscrapers clues count the number of line shapes seen from that direction, where each "digit" blocks the view of smaller or equal digits.
- Clues to the right and bottom of the grid are Skyscrapers clues. On the left and top side the Skyscrapers clues are mixed in with Summation U-Bahn clues. If there are both Summation U-Bahn and Skyscrapers clues in a row of column, the Skyscrapers clue can appear anywhere. If there is a single clue in a row or column, it can be either Summation U-Bahn or Skyscrapers.
- Each letter represents a different number. A "?" may represent any number, including two-digit numbers.
Puzzle links
Solution code: For each row except the last, from top to bottom, the number of lines leading down from that row.
Comments
on 8. July 2026, 20:43 by boomsoon
Really great! I was excited to do the whole series but skipped to this one because the skyscrapers caught my eye. I'll have to go back and do all of them now. Thanks for making it!
on 7. April 2026, 10:16 by Playmaker6174
Such a gorgeous (and quite challenging) puzzle!
The first half was rather tricky to spot the desired deductions but I really enjoyed how certain letters were concluded in that part, and I also enjoyed how the puzzle gradually came together later on. x)
on 19. November 2024, 22:34 by Myxo
Awesome!!!
on 19. November 2024, 22:33 by Bellsita
Fantastic puzzle!
on 19. November 2024, 22:26 by wisty
Awesome
on 29. October 2024, 13:26 by MagnusJosefsson
Wonderful puzzle! Very challenging and rewarding!
on 27. October 2024, 22:48 by Piatato
Amazing puzzle, very cleverly constructed and a great pleasure to solve!
on 17. October 2024, 17:39 by ibag
Great - and quite difficult!
on 8. October 2024, 13:02 by Christounet
What a great puzzle again ! Love this serie. Easier than the previous one for me, or maybe I am just getting more familiar with the fundamental logic of the ruleset. Thanks :)
on 6. October 2024, 04:46 by RJBlarmo
Fantastic series! All of these have been great fun to solve, would love to see more Summation U-Bahn puzzles!
on 4. October 2024, 00:41 by Samish
Absolutely wonderful puzzle, it never ceased to amaze me from start to finish. What a masterpiece, thanks!
on 1. October 2024, 23:47 by Jesper
Great puzzle, really good fun!
on 30. September 2024, 15:35 by ONeill
An excellent addition to the series. Some of the clues are surprisingly powerful in this one. More please :)
