《手撕链表题系列-7》链表的回文结构

/*
struct ListNode {
    int val;
    struct ListNode *next;
    ListNode(int x) : val(x), next(NULL) {}
};*/
class PalindromeList {
public:
    bool chkPalindrome(ListNode* A) {
        //快慢指针找到中间结点
        struct ListNode*fast=A,*slow=A;
        while(fast&&fast->next)
        {
            fast=fast->next->next;
            slow=slow->next;
        }
        struct ListNode*cur=slow;
        //两个指针用来逆转节点方向
        struct ListNode*prev=NULL,*next;
        while(cur)
        {
            struct ListNode*Next=cur->next;
            cur->next=prev;
            prev=cur;
            cur=Next;
        }
        //遍历比较
        struct ListNode*cur1=A,*cur2=prev;
        while(cur1&&cur2)
        {
            if(cur1->val==cur2->val)
            {
                cur1=cur1->next;
                cur2=cur2->next;
            }
            else
                return false;
        }
        return true;
    }
};