LeetCode-in-Java
258. Add Digits
Easy
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
Follow up: Could you do it without any loop/recursion in O(1) runtime?
Solution
public class Solution {
public int addDigits(int num) {
if (num == 0) {
return 0;
}
if (num % 9 == 0) {
return 9;
}
return num % 9;
}
}