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 class Solution {
    /**
     *
     * @param head ListNode类 the head
     * @return bool布尔型
     */
    public boolean isPail (ListNode head) {
        // write code here
	  //将节点添加到栈里
        ListNode tmp=head;
        Stack<Integer> stack = new Stack<>();
        while (tmp != null) {
            stack.push(tmp.val);
            tmp = tmp.next;
        }
	  //对比链表每个节点与栈中取出的节点
        while(head!=null&&!stack.isEmpty()){
            Integer tmpNode=stack.pop();
		  //不一样就不是回文链表
            if(head.val!=tmpNode){
                return false;
            }
            head=head.next;
        }

        return true;
    }
}