```
class Solution(object):
def plusOne(self, digits):
"""
:type digits: List[int]
:rtype: List[int]
"""
carry = 1
for i in range(len(digits)-1, -1, -1):
num = carry + digits[i]
if (num > 9):
carry = 1
else:
carry = 0
digits[i] = num%10
if carry == 1:
digits.insert(0,1)
return digits
```
```