[Leetcode][python]Plus One/加一

class Solution(object):
    def plusOne(self, digits):
        """
        :type digits: List[int]
        :rtype: List[int]
        """
        flag = 1
        for i in range(len(digits)-1, -1, -1):
            if flag == 1:
                digits[i] += 1
                if digits[i] >= 10:
                    digits[i] = 0
                else:
                    flag = 0
        if flag == 1:
            digits.insert(0,1)
        return digits

class Solution:
    def plusOne(self, digits):
        for i in range(len(digits)-1,-1,-1):
            if digits[i]<9:
                digits[i]=digits[i]+1
                return digits
            else:
                digits[i]=0
        digits.insert(0,1)
        return digits