K Sized Subarray Maximum

import java.util.*;

class Solution {
    // Function to find maximum of each subarray of size k.
    public ArrayList<Integer> max_of_subarrays(int k, int arr[]) {
        ArrayList<Integer> result = new ArrayList<>();
        Deque<Integer> deque = new LinkedList<>();

        for (int i = 0; i < k; i++) {
            while (!deque.isEmpty() && arr[i] >= arr[deque.peekLast()])
                deque.removeLast();

            deque.addLast(i);
        }

        for (int i = k; i < arr.length; i++) {
            result.add(arr[deque.peek()]);

            while (!deque.isEmpty() && deque.peek() <= i - k)
                deque.removeFirst();

            while (!deque.isEmpty() && arr[i] >= arr[deque.peekLast()])
                deque.removeLast();

            deque.addLast(i);
        }

        result.add(arr[deque.peek()]);

        return result;
    }
}