boolean contains(String s, int i, int j) {
        if ((i < 10 || j < 10) && !s.contains("0"))
            return false;
        while (i != 0) {
            if (!s.contains(i % 10 + ""))
                return false;
            i /= 10;
        }

        while (j != 0) {
            if (!s.contains(j % 10 + ""))
                return false;
            j /= 10;
        }

        return true;
    }
Why Did you create this class? what does it do?
src/problems/medium/NextClosestTime.java