Full Visibility Clue

Easy Used by Smart Hint

A clue equal to the grid size means every building is taller than the last — the whole line is forced into one exact order.

Cells that establish the pattern
Where the conclusion lands

How it works

The 4 on the top edge says all four buildings are visible down that column — every one must be taller than the last.
Only one order does that: 1, 2, 3, 4 from the clue inward.
The whole line is forced in a single stroke, starting with the 1 at the top.