leetcode

0 class Solution {

1 public:

2 ListNode *swapNodes(ListNode *head, int k) {

3 ListNode *tmp = head, *first;

4 while (--k)

5 tmp = tmp->next;

6 first = tmp;

7

8 ListNode *second = head;

9 tmp = tmp->next;

10 while (tmp)

11 tmp = tmp->next, second = second->next;

12 swap(first->val, second->val);

13 return head;

14 }

15 };