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