LeetCode -- Add Digits

LeetCode -- Add Digits

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


For example:


Given num = 38, the process is like: 3 + 8 = 11, 1 + 1 = 2. Since 2 has only one digit, return it.




就是給定一個數字n，將每一位相加，再判斷和是否只有一位：
只有1位：返回這個和
否則：繼續相加每一位，判斷新的和






實現代碼：

public class Solution {
    public int AddDigits(int num) {
         if(num < 10){
            return num;
        }
        
        var n = num;
		
		while(true){
			var s = 0;
			while(n >= 10){
				s+= n % 10;
				n /= 10;
			}
			s += n;
			
			if(s < 10){
				return s;
			}
			n = s;
		}
    }
}