问题描述 该题考察的是动态规划

class Solution:
    def climbStairs(self, n: int) -> int:
        dp = [0]*n
        if n == 1:
            return 1
        dp[0] = 1
        dp[1] = 2
        for i in range(2,n):
            dp[i] = dp[i-1] + dp[i-2]
        return dp[n-1]

运行结果：