Skyscraper· Advanced

Goal

Use the number clues around the border to fill each row and column with 1 to N without repeats

Rules

  • No duplicate numbers in any row
  • No duplicate numbers in any column
  • Border clues show how many buildings are visible from that direction (taller buildings hide shorter ones behind them)
21433412432112343212232122142241

A clue of 1 means the tallest building (N) is first. A clue of N means buildings are in ascending order.

Use pencil marks to narrow down possibilities, starting with cells that have only one option.

Constraint-based number puzzles train logical reasoning and working memory simultaneously. Significant improvements across 14 cognitive measures were reported in adults 50+, and tasks requiring perspective shifts activate spatial reasoning and prefrontal executive functions.

  • Number puzzles and 14 cognitive measures in adults 50+ (Int J Geriatr Psychiatry, 2019)
  • Perspective-taking and spatial reasoning activate prefrontal cortex (NeuroImage, 2017)