Java solution - passes 100% of test cases

From my HackerRank solutions.

We want to sort in descending order while preserving the contents of each String. A comparator can achieve this for us. We convert to BigDecimal inside our comparator so that the change is not permanent and our String's form for each number is preserved.

Comparator<String> customComparator = new Comparator<String>() {
    @Override
    public int compare(String s1, String s2) {
        BigDecimal a = new BigDecimal(s1);
        BigDecimal b = new BigDecimal(s2);
        return b.compareTo(a); // descending order
    }
};

Arrays.sort(s, 0, n, customComparator);

Let me know if you have any questions.