n=4的一些解
..0..1..0..2..1....0..1..0..2..1....0..1..0..0..1....0..1..0..1..0
..0..1..0..2..1....0..1..0..2..1....0..1..0..0..1....0..1..0..1..0
..1..0..0..1..2....0..1..2..2..1....0..1..0..0..1....0..2..0..1..2
..1..0..2..1..2....0..2..2..1..0....2..1..2..2..1....1..2..2..0..2
..1..0..2..1..2....0..2..2..1..0....2..1..2..2..1....1..2..2..0..2