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) {
        // write code here
        Stack<Integer> stacks = new Stack<>();
        ListNode nodes = new ListNode(-1);
        ListNode cur = nodes;
        while (head != null) {
            stacks.add(head.val);
            cur.next = head;
            cur = cur.next;
            head = head.next;
        }
        ListNode res = nodes.next;
        while (!stacks.isEmpty()) {
            if (stacks.pop() != res.val) {
                return false;
            }
            res = res.next;
        }
        return true;
    }
}

遍历原始链表，创建一个空的栈，新的链表，通过栈先进后出，和新链表数据对比，如果是回文，数据完全相同