Skyscrapers Latin square: Put a number between 1 and 7 into each cell inclusive such that each row and column contains exactly one instance of each number. If we consider the numbers as heights of buildings, each number outside the grid tells the number of buildings visible from that point, looking into the grid. For example, an observer to the left of the sequence 1426375 sees four buildings (1,4,6,7; other buildings are hidden by taller buildings to the left).
Expected difficulty Medium • Answer • Comment/E-mail if you want a solution to be published
Puzzle 81: Fell from the Sky
Skyscrapers
This is the first in the series of the rejected puzzles for FAST, a joke test for April Fools Day. As described in a post in the discussion thread, my initial idea was “normal-sized” puzzles (even though I actually had 12×12’s and not 10×10’s), but with answer keys that are trivial to obtain. This, in some cases, lend to actually trivial puzzles too, but I don’t really like that, and hence here’s a handpicked collection of puzzles that I deem to be interesting enough even with the trivial answer key restriction. (Thus the title follows; the puzzles are those that “fell from the sky”, failed to be picked for the party.)
Chaos at the Sky 
