import java.util.*; public class Solution { public boolean isPail (ListNode head) { ArrayList<Integer> nums = new ArrayList(); //将链表元素取出一次放入数组 while(head != null){ nums.add(head.val); head = head.next; } ArrayList<Integer> temp = new ArrayList(); temp = (ArrayList<Integer>) nums.clone(); //准备一个数组承接翻转之后的数组 Collections.reverse(temp); for(int i = 0; i < nums.size(); i++){ int x = nums.get(i); int y = temp.get(i); //正向遍历与反向遍历相同 if(x != y) return false; } return true; } }