LeetCode - 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 .

class Solution {

    public List<Integer> selfDividingNumbers(int left, int right) {

        left = left < 1 ? 1 : left;

        List<Integer> list = new ArrayList<Integer>();

        if (right < left)

            return list;

        for (int i=left; i<=right; i++)

            if (isSelf(i))

                list.add(i);

        return list;

    }

    private boolean isSelf(int n) {

        String ns = String.valueOf(n);

        for (int i=0; i<ns.length(); i++) {

            int nsn = ns.charAt(i)-'0';

            if (nsn == 0 || (n % nsn) != 0)

                return false;

        }

        return true;

    }

}