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