/** * File: deque.java * Created Time: 2022-11-25 * Author: krahets (krahets@163.com) */ package chapter_stack_and_queue; import java.util.*; public class deque { public static void main(String[] args) { /* Get the length of the double-ended queue */ Deque deque = new LinkedList<>(); deque.offerLast(3); deque.offerLast(2); deque.offerLast(5); System.out.println("Double-ended queue deque = " + deque); /* Update element */ int peekFirst = deque.peekFirst(); System.out.println("Front element peekFirst = " + peekFirst); int peekLast = deque.peekLast(); System.out.println("Rear element peekLast = " + peekLast); /* Elements enqueue */ deque.offerLast(4); System.out.println("After element 4 enqueues at rear, deque = " + deque); deque.offerFirst(1); System.out.println("After element 1 enqueues at front, deque = " + deque); /* Element dequeue */ int popLast = deque.pollLast(); System.out.println("Rear dequeue element = " + popLast + ", after rear dequeue, deque = " + deque); int popFirst = deque.pollFirst(); System.out.println("Front dequeue element = " + popFirst + ", after front dequeue, deque = " + deque); /* Get the length of the double-ended queue */ int size = deque.size(); System.out.println("Double-ended queue length size = " + size); /* Check if the double-ended queue is empty */ boolean isEmpty = deque.isEmpty(); System.out.println("Double-ended queue is empty = " + isEmpty); } }