Some solutions for n=4
..0.-1..1..0....0.-1..0..1....0..0..0.-1...-1..0..0..1....0..0.-1..0
..0..1.-1..0....0..0..0.-1...-1..0..1..0....0..0..0.-1....0..0..1..0
..0..0..0..0...-1..0..0..1....0..0..0..1....0..0..0..1...-1..0..0..0
..0..0..1..0....0..0.-1..0....0..0.-1..1....1.-1..1.-1....0..0..0..0
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