[leetCode] 258. Add Digits (Python)

Given a non-negative integer num, repeatedly add all its digits until the result has only one digit.

 

Example:

Input: 38
Output: 2 
Explanation: The process is like: 3 + 8 = 11, 1 + 1 = 2. 
             Since 2 has only one digit, return it.

Follow up:
Could you do it without any loop/recursion in O(1) runtime?

 

Solution

class Solution:
    def addDigits(self, num: int) -> int:
        while True:
            if num // 10 < 1:
                return num
            
            num_list = list(map(int, list(str(num))))
            
            sum_num = sum(num_list)
            
            num = sum_num

SOMJANG/CODINGTEST_PRACTICE