n=4的一些解决方案:
..0..0....0..0....0..0....1..1....0..0....0..0....0..0....0..0....0..1....1..0
..1..1....1..1....1..0....0..0....1..1....0..0....0..3....0..0....0..1....1..0
..0..0....0..0....1..0....0..3....2..2....0..3....1..0....3..0....1..0....0..0
..1..1....0..0....0..0....0..0....1..1....0..0....1..0....0..0....1..0....0..0