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