题解 | #判断一个链表是否为回文结构#

import java.util.*;

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param head ListNode类 the head
     * @return bool布尔型
     */
    public boolean isPail (ListNode head) {
        ArrayList<Integer> arr = new ArrayList<>();
        while(head != null) {
            arr.add(head.val);
            head = head.next;
        }
        for(int i = 0; i < arr.size(); i++) {
            int a = arr.get(i);
            int b = arr.get(arr.size() - 1 - i);
            if(a != b) return false;
        }
        return true;
    }
}