n=4的一些解
..3..3....3..3....3..2....3..2....2..2....3..3....3..3....3..3....2..2....2..2
..2..2....2..1....3..2....3..1....0..2....2..1....2..1....2..1....0..2....0..2
..3..1....0..2....0..3....2..2....0..3....3..2....3..2....3..2....0..3....0..2
..2..1....3..2....0..3....3..1....2..2....0..2....3..2....3..1....0..3....0..2