234.回文链表

class Solution {
public:
    bool isPalindrome(ListNode* head) 
    {
        if(!head || !head->next) return true;
        ListNode * fast = head;
        ListNode * slow = head;
        while(fast && fast->next)
        {
            fast = fast->next->next;
            slow = slow->next;
        }
        ListNode * curnode = slow;
        ListNode * nextnode = slow->next;
        while(nextnode)
        {
            ListNode * temp = nextnode->next;
            nextnode->next = curnode;
            curnode = nextnode;
            nextnode = temp;
        }
        slow->next = NULL;
        while(head && curnode)
        {
            if(head->val != curnode->val) return false;
            head = head->next;
            curnode = curnode->next;
        }
        return true;
    }
};

[[C++]Leetcode超高效刷题顺序及题目详解笔记（持续更新中）]