n=4的一些解决方案:
..0..0. .0..1. .0..1. .0..1. .0..1. .0..1. .0..0. .0..1. .0..0. .0..0
..1..2. .2..1. .2..2. .0..2. .0..2. .2..2. .1..2. .1..2. .1..1. .1..2
..1..0. .2..0. .1..0. .1..1. .1..1. .1..1. .0..0. .0..0. .0..2. .0..2
..0..2. .1..1. .0..2. .0..2. .2..2. .0..0. .1..1. .1..1. .1..0. .0..1