Add Digits

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.

class Solution {public:    int addDigits(int num) {        while(num>=10){            int result = 0;            while(num != 0){                result += num%10;                num = num/10;            }            num = result;        }        return num;    }};