n=7的一些解
..0..2....1..2....2..0....0..0....2..1....2..1....1..1....2..0....2..0....0..1
..0..2....1..1....3..0....2..2....1..1....2..1....0..0....0..0....1..0....0..2
..0..3....1..1....1..0....2..3....1..1....0..0....0..0....0..0....0..0....0..3
..0..3....3..3....0..0....0..0....1..1....0..0....1..2....2..2....0..0....0..0
..0..2....0..0....0..0....0..0....2..2....1..0....1..1....3..3....0..0....0..0
..0..0....0..0....3..2....1..1....2..2....3..0....3..1....0..0....2..2....0..0
..3..0....2..0....2..2....1..2....3..3....3..0....0..0....0..0....2..3....3..0