leetcode

0 class Solution {

1 public:

2 ListNode *removeNthFromEnd(ListNode *head, int n) {

3 ListNode *b = head;

4

5 n++;

6 for (ListNode *a = head; a; a = a->next) {

7 if (!n)

8 b = b->next;

9 else

10 n--;

11 }

12 if (n)

13 head = head->next;

14 else

15 b->next = b->next->next;

16 return head;

17 }

18 };