There is an error in the input data (both in assert and the main test):

[ [1, 1, 4, 5, 3.5], [2, 6, 4, 8, 5], [5, 1, 9, 3, 6], [5, 5, 6, 6, 8], [7, 4, 4, 10, 6], [5, 7, 3, 10, 8] ]

Take a look at two last buildings, they should be:

[7, 4, 10, 6, 4],
[5, 7, 10, 8, 3]

Even if they are other buildings than in the example above, their coordinates can't be [Xsw, Ysw, Xne, Yne, height] anyway.

I can fix assert, but I can't pass the server test (even if I totally ignore wrong buildings).

Thanks!