import java.util.ArrayDeque; import java.util.Scanner; public class Main { public static void main(String[] args) { ArrayDeque deque = new ArrayDeque(); Scanner scanner = new Scanner(System.in); while (scanner.hasNext()) { String name = scanner.next(); // 初始化队列中的数据 deque.offerLast(name); } // write your code here...... boolean flag=true; while(deque.size()!=0) { if(flag) { System.out.println(deque.pollFirst()); } else{ System.out.println(deque.pollLast()); } flag=!flag; } } }