GridWits
Medium tier Technique 5 of 21 Smart Hint: Skyscrapers and Skyscrapers+

Visible-Count Bound

At each position, leave enough taller heights behind to reach the clue's visible count — eliminate every height too tall to allow that.

How it works

  1. 1The 3 on the left says three buildings are visible along this row.
  2. 2In the first cell, a height 3 would leave only the 4 taller behind it: even if both were visible, the row could show at most two buildings. So the first cell can be at most 2.
  3. 3One position farther in, height 3 is still possible but 4 would end the skyline too soon. Strike 3 and 4 from the first cell, and 4 from the second.
1 2 3 4 1 2 3 4 3
  • Height ruled out
  • Relationship — The arrow shows which cells support the deduction.
Next in the ladder Line Consistency (≤4 Blanks) →

Every way to fill this row or column's remaining heights that matches its clue was checked — a height eliminated here doesn't appear in any of them. Enough of the line was already filled in that there was not much left to weigh.