5383. 给 N x 3 网格图涂色的方案数

class Solution:
    def numOfWays(self, n: int) -> int:
        same, diff = 6, 6  # 代表初始时第一行两类各6种
        for k in range(1, n):
            same, diff = same * 3 + diff * 2, same * 2 + diff * 2
        return (same + diff) % (10 ** 9 + 7)