add-digits.cpp

//question//

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


//solution//


class Solution {
public:
    int addDigits(int num) {
       unsigned int ans = 0;
        while(num>0)
        {
            unsigned int rem = num%10;
            ans += rem;
            num = num/10;
            if(num==0 && ans>9)
            {
                num = ans;
                ans = 0;
            }
        }
        return ans;
    }
};