iterative merge sort

public static long[] sortIterative(long[] data) {
    Queue<long[]> q = new LinkedList<>();
    for (long elt : data) {
        q.add(new long[]{elt});
    }

    while (q.size() > 1) {
        long[] res = mergeSorted(q.poll(), q.poll());
        q.add(res);
    }

    return q.poll();
}