258_Add Digits_3.java

/**
 *  @author WasitShafi
 *  @since 25-SEP-2020
 */

class Solution {
  public int addDigits(int num) {
    if (num == 0) {
      return num;
    } else if (num % 9 == 0) {
      return 9;
    } else {
      return num % 9;
    }
  }
}