LeetCode - Add Digits

题目：

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.

思路：

除和余

package others;

public class AddDigits {

public int addDigits(int num) {
if (num / 10 == 0) return num;
int res = 0;
while (num > 0) {
res += num % 10;
num = num / 10;
}
return addDigits(res);
}

public static void main(String[] args) {
// TODO Auto-generated method stub

}

}