Add Digits

https://leetcode.com/problems/add-digits/

class Solution {
public:
    int addDigits(int num) {
        int res=num;
        while(oneDigit(res)==false)
        {
            int temp=0;
            while(res!=0)
            {
                temp+=res%10;
                res/=10;
            }
            res=temp;
        }
        return res;
    }
    bool oneDigit(int num)
    {
        if(num<=9)
            return true;
        else
            return false;
    }
};