在Java中创建一个栈和一个队列

创建栈的示例代码如下：

import java.util.Stack;

public class StackExample {
    public static void main(String[] args) {
        Stack<Integer> stack = new Stack<>();
        stack.push(1);
        stack.push(2);
        stack.push(3);
        System.out.println("Stack elements: " + stack);
        System.out.println("Top element: " + stack.peek());
        stack.pop();
        System.out.println("Stack elements after pop: " + stack);
    }
}

创建队列的示例代码如下：

import java.util.LinkedList;
import java.util.Queue;

public class QueueExample {
    public static void main(String[] args) {
        Queue<String> queue = new LinkedList<>();
        queue.add("Alice");
        queue.add("Bob");
        queue.add("Charlie");
        System.out.println("Queue elements: " + queue);
        System.out.println("Front element: " + queue.peek());
        queue.remove();
        System.out.println("Queue elements after remove: " + queue);
    }
}