[Leetcode] 66. Plus One

題目：66. Plus One

You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's.

Increment the large integer by one and return the resulting array of digits.

Example 1:

Input: digits = [1,2,3]
Output: [1,2,4]
Explanation: The array represents the integer 123.
Incrementing by one gives 123 + 1 = 124.
Thus, the result should be [1,2,4].

Example 2:

Input: digits = [4,3,2,1]
Output: [4,3,2,2]
Explanation: The array represents the integer 4321.
Incrementing by one gives 4321 + 1 = 4322.
Thus, the result should be [4,3,2,2].

Example 3:

Input: digits = [9]
Output: [1,0]
Explanation: The array represents the integer 9.
Incrementing by one gives 9 + 1 = 10.
Thus, the result should be [1,0].

１.

class Solution:
    def plusOne(self, digits: List[int]) -> List[int]:
        # 將字串轉數字，再+1
        num = int("".join(str(i) for i in digits )) + 1
        ans = []
        # 將num%10的餘數append到ans
        while num != 0:
            ans.append(num % 10)
            num //= 10
        #最後的ans會是倒序的數字，會以要將ans做反轉
        return reversed(ans)