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