The skyscrapers puzzle (City)

The skyscrapers puzzle is a cousin of sudoku. In Grafite Sudoku it is called City, and it is a mode you only find in the app.

The rules

• Every cell is a building, with a height from 1 up to the size of the grid.
• Each height appears exactly once in every row and every column.
• The numbers on the edge say how many buildings you see from there along that row or column: a lower building is hidden behind a taller one.

First strategies

• A clue equal to the grid size means buildings in increasing order: 1, 2, 3, 4.
• A clue of 1 means the tallest building is right in front of you.
• A high clue keeps tall buildings out of the first cells: they would hide the ones behind.

In the City of Grafite Sudoku the grids are 5×5 and 6×6, with dedicated lessons in the Sudoku Academy.