Fill the grid with digits from 1 to n, such that each row and each column contains exactly one of each digit. Put one digit in each half of split cells. Cells correspond to skyscrapers, their height given by the numbers. For split cells, the height is the fraction formed by the two digits.
The numbers outside the grid indicate the number of visible skyscrapers when looking along the corresponding row or column from that point. Skyscrapers are blocked from view by those of equal or greater height.
Maybe Puzzles 
while i get the addition of the ‘split cells’ the explanation is, in my opinion, inaccurate.
“For split cells, the height is the fraction formed by the two digits.”
In the example top left box with the 3/1 split, 3/1 = 3 and so if you take the instructions literally the ‘2’ in the outside is incorrect as 3/1 > 2 so you’d only be able to see the ‘3/1’ Skyscraper.
The explanation only works if you state that for split cells the ‘lower’ number always goes in the ‘top’ part of the split cell – i.e. 1/3 not 3/1.
That’s correct, though: The top row is 3/1 2 4, and indeed 3/1 > 2, but 3/1 < 4, so the number of buildings you see from the left is 2. Or am I missing something?