Skyscrapers: Each cell represents a ‘skyscraper’ whose height is the digit in that cell. Taller skyscrapers obscure the view of smaller ones. Clues outside the grid tell how many skyscrapers are visible looking across the row or column from the direction of the clue.
Zipper Line: Along Zipper lines, pairs of digits equidistant from the center of the line have the same sum, which is the central digit on the line.
We categorized this puzzle as Heartburn. For more information about our difficulty categories, please visit our website, Missing Deck Puzzles, where we publish a new puzzle each day.
Try the puzzle on the SudokuPad app by Sven Neumann.
Solution code: Row 5, left to right, 9 digits no spaces