Place a number from 1 to X (integers only) into each cell so that each number appears exactly once in each row and column. (X is the number of cells in each row.) Each number represents a skyscraper of its respective height. The numbers outside the grid indicate how many skyscrapers can be seen in the respective row or column from the respective direction; smaller skyscrapers are hidden behind higher ones.
(Rules and example from PGP IB)
- Skyscrapers with Parks: Some cells may remain empty. Invented by Tim Peeters in 1999.
- Greater Than Skyscrapers from WPC 2016/Round 2: Some greater-than symbols are given between edgewise adjacent cells.
History of the puzzle
Invented by Masanori Natsuhara (Japan) in 1992 in the Puzzler magazine. Originally entitled "ビルディングシティパズル" (Building City Puzzle).
Appearances in the past WPCs
Listed here are appearances of classic to almost-classic Skyscrapers. For variants, see list of Skyscrapers variants#Appearances in the past WPCs.
- WPC 2019/Round 2 by Gabi Penn-Karras
- WPC 2019/Round 9 by Ulrich Voigt
- WPC 2019/World Cup Playoffs by Roland Voigt
- WPC 2018/Round 4 (Hexagonal) by František Luskač
- WPC 2018/Round 4 (Pyramidal combination) by Jiří Hrdina
- WPC 2018/Round 11 (Combination with Easy as, combination with itself) by Jiří Hrdina
- WPC 2018/Round 13 (Coded) by Jiří Hrdina
- WPC 2018/Individual Playoffs (Skyscrapers with Parks, unused) by Jiří Hrdina
- WPC 2017/Round 3 by Rohan Rao and Ashish Kumar
- WPC 2017/Round 10 ("Optimizer") by Deb Mohanty
- WPC 2016/Round 2 (Greater Than Skyscrapers) by Matej Uher
- WPC 2016/Round 6 (Combination) by Matej Uher
- WPC 2016/Round 9 by Matej Uher and Matúš Demiger