题解 | #判断一个链表是否为回文结构#

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param head ListNode类 the head
     * @return bool布尔型
     */
    public boolean isPail (ListNode head) {
        // write code here
        if (head == null || head.next == null) {
            return true;
        }
        List<Integer> list = new ArrayList<>();
        while (head != null) {
            list.add(head.val);
            head = head.next;
        }
        int l = 0;
        int r = list.size() - 1;
        while (l < r) {
            if (list.get(l).intValue() != list.get(r).intValue()) {
                return false;
            }
            l++;
            r--;
        }
        return true;
    }
}