初阶数据结构-链表的回文结构

struct ListNode* middleNode(struct ListNode* head) {
        struct ListNode* slow = head, * fast = head;
        while (fast && fast->next) {
            slow = slow->next;
            fast = fast->next->next;
        }

        return slow;
    }

struct ListNode* reverseList(struct ListNode* head) {
        struct ListNode* cur = head;
        struct ListNode* newhead = NULL;

        while (cur) {
            struct ListNode* next = cur->next;
            //头插
            cur->next = newhead;
            newhead = cur;

            cur = next;
        }

        return newhead;
    }

 struct ListNode* mid = middleNode(A);
    struct ListNode* rmid = reverseList(mid);

        while(rmid && A)
        {
            if(rmid->val != A->val)
            return false;
            rmid = rmid->next;
            A = A->next;
        }

    return true;
    }