Add the chapter of stack and queue.

codes/java/chapter_stack_and_queue/deque.java

@@ -0,0 +1,37 @@
+package chapter_stack_and_queue;
+
+import java.util.*;
+
+public class deque {
+    public static void main(String[] args) {
+        /* 初始化队列 */
+        Deque<Integer> deque = new LinkedList<>();
+
+        /* 元素入队 */
+        deque.offerLast(2);
+        deque.offerLast(5);
+        deque.offerLast(4);
+        deque.offerFirst(3);
+        deque.offerFirst(1);
+        System.out.println("队列 deque = " + deque);
+
+        /* 访问队首元素 */
+        int peekFirst = deque.peekFirst();
+        System.out.println("队首元素 peekFirst = " + peekFirst);
+        int peekLast = deque.peekLast();
+        System.out.println("队尾元素 peekLast = " + peekLast);
+
+        /* 元素出队 */
+        int pollFirst = deque.pollFirst();
+        System.out.println("队首出队元素 pollFirst = " + pollFirst + "，队首出队后 deque = " + deque);
+        int pollLast = deque.pollLast();
+        System.out.println("队尾出队元素 pollLast = " + pollLast + "，队尾出队后 deque = " + deque);
+
+        /* 获取队列的长度 */
+        int size = deque.size();
+        System.out.println("队列长度 size = " + size);
+
+        /* 判断队列是否为空 */
+        boolean isEmpty = deque.isEmpty();
+    }
+}