题解 | #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
        stack<int> stk;
        ListNode* p = head;
        int len = 0;
        while(p != nullptr){
            len++;
            p = p->next;
        }
        p = head;
        int temp = len / 2;
        while(temp--){
            stk.push(p->val);
            p = p->next;
        }
        if(len % 2 == 1){
            p = p->next;
        }
        while(p!=nullptr && !stk.empty()){
            if(p->val == stk.top()){
                p = p->next;
                stk.pop();
            }
            else return false;
        }
        return true;
    }
};