python(二十六) 缓存结果 lru cache

from functools import lru_cache

class Solution:
    @lru_cache(None)
    def climbStairs(self,n):
        if n == 1:
            return 1
        elif n == 2:
            return 2
        else:
            return self.climbStairs(n-1)+self.climbStairs(n-2)