leetcode

0 class Solution {

1 public:

2 ListNode *reverseList(ListNode *head) {

3 ListNode *p, *q, *r;

4

5 p = head, q = nullptr;

6 while (p) {

7 r = q;

8 q = p;

9 p = p->next;

10 q->next = r;

11 }

12

13 return q;

14 }

15 };