法一：
class Solution:
    def plusOne(self, digits: List[int]) -> List[int]:
        length = len(digits)
        res = 0
        for i in digits:
            if digits[-1]!=9:
                if length!=1:
                    res+=i*int('1'+'0'*(length-1))
                    length-=1
                else
 
:
                    res += (i+1)
            else:
                if length!=1:
                    res+=i*int('1'+'0'*(length-1))
                    length-=1
                else:
                    res += 10
        res = [int(num) for num in str(res)]
        return res
法二：

class Solution:
　　def plusOne(self, digits: List[int]) -> List[int]: