258. Add Digits

Easy (Dễ) Python 🔗 Xem trên LeetCode

📋 Đề Bài

Given an integer num, repeatedly add all its digits until the result has only one digit, and return it.

 

Example 1:

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

Example 2:

Input: num = 0
Output: 0

 

Constraints:

  • 0 <= num <= 231 - 1

 

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

💻 Lời Giải

Python 0258-add-digits.py
class Solution:
    def addDigits(self, num: int) -> int:
        total = num
        
        while num >= 10:
            total = sum(map(int, str(num)))
            num = total
            
        return total