Dotted Skyscrapers/en

Instructions

Fill the grid with digits from the given range, so that each digits appears exactly once in every row and column. Each digit represents a building, with the height of that digit itself. Clues outside the grid indicate the number of buildings that can be seen from the corresponding directions, taking into account that the higher buildings block the view of lower ones.

All neighbouring pairs where one digit is twice as the other one is marked by a black dot.

History

Variant developed by Roland Voigt (Germany).