每天(?)一道Leetcode(6) Plus One

Array

066. Plus One

Given a non-empty array of digits representing a non-negative integer, plus one to the integer.
The digits are stored such that the most significant digit is at the head of the list, and each element in the array contain a single digit.
You may assume the integer does not contain any leading zero, except the number 0 itself.
即：十进制加法 但每次只加一

Solutions

从个位开始加，如果当前位置为,则加之后为,前一位继续加，直到当前位置不是，加之后结束。
需要注意的是所给数字全为的情况，如

class Solution:
    def plusOne(self, digits):
        """
        :type digits: List[int]
        :rtype: List[int]
        """
        
        for i in reversed(range(len(digits))):
            if digits[i] == 9:
                digits[i] = 0
            else:
                digits[i] += 1
                return digits
        digits[0] = 1
        digits.append(0)
        return digits