BM13判断一个链表是否为回文结构

/**
 * struct ListNode {
 *  int val;
 *  struct ListNode *next;
 * };
 */
class Solution {
public:
    /**
     * 
     * @param head ListNode类 the head
     * @return bool布尔型
     */
    bool isPail(ListNode* head) {
        // write code here
        //直接用栈写 okk
        stack<int>sta;
        ListNode *p = head;
        while(p != nullptr)
        {
            sta.push(p->val);
            p = p->next;
        }
        p = head;
        while(p != nullptr)
        {
            if(p->val != sta.top())
            {
                break;
            }
            sta.pop();
            p = p->next;
        }
        if(p == nullptr)
        {
            return true;
        }
        return false;
    }
};