66. Plus One

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

        if (digits[len(digits)-1]+1) <= 9:
            digits[len(digits)-1]+=1
            return digits
        else:
            digits[len(digits)-1]+=1

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