_728.java

package com.fishercoder.solutions;

import java.util.ArrayList;
import java.util.List;

/**
 * 728. Self Dividing Numbers
 *
 * A self-dividing number is a number that is divisible by every digit it contains.
 * For example, 128 is a self-dividing number because 128 % 1 == 0, 128 % 2 == 0, and 128 % 8 == 0.
 * Also, a self-dividing number is not allowed to contain the digit zero.
 * Given a lower and upper number bound, output a list of every possible self dividing number, including the bounds if possible.

 Example 1:
 Input:
 left = 1, right = 22
 Output: [1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 22]
 Note:

 The boundaries of each input argument are 1 <= left <= right <= 10000.
 */
public class _728 {
    public static class Solution1 {
        public List<Integer> selfDividingNumbers(int left, int right) {
            List<Integer> result = new ArrayList<>();
            for (int num = left; num <= right; num++) {
                if (isSelfDividing(num)) {
                    result.add(num);
                }
            }
            return result;
        }

        private boolean isSelfDividing(int num) {
            int tmp = num;
            while (tmp != 0) {
                int digit = tmp % 10;
                if (digit == 0 || num % digit != 0) {
                    return false;
                }
                tmp /= 10;
            }
            return true;
        }
    }
}