LeetCode-258. 各位相加-C语言

int addDigits(int num){
    if(num > 9) 
        return num%9 ? num%9 : 9;

    return num;
}

int addDigits(int num){
    int tmp, cnt;
    while(num >=10) {
        tmp = num;
        cnt = 0;
        while(tmp){
            cnt += tmp%10;
            tmp /= 10;
        }
        num = cnt;
    }

    return num;
}