Find the K largest elements in an unsorted array

topKElements.java

public static int[] topK(int[] arr, int k) {
	// default is ascending order
	Queue<Integer> queue = new PriorityQueue<Integer>();
	int i = 0;
	for (; i < k; i++) {
		queue.add(arr[i]);
	}
	for (; i < arr.length; i++) {
		queue.add(arr[i]);
		queue.poll(); // Retrieves and removes the head of this queue, which is smallest element in the queue
	}
	int[] res = new int[k];
	for (int j = 0; j < k; j++) {
		res[j] = queue.poll();
	}
	return res;
}