Remove Nth Node From End of List

 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     ListNode* removeNthFromEnd(ListNode* head, int n) {
12         int l=2;
13         int i=2;
14         ListNode *temp,*tt;
15         temp=head->next;
16         if(temp==NULL)
17         {
18             if(n==0) return head;
19             else return NULL;
20         }
21         while(temp->next!=NULL)
22         {
23             temp=temp->next;
24             l++;
25         }
26         if(n==l)
27         {
28             return head->next;
29             free(head);
30         }
31         temp=head;
32         while(temp->next!=NULL)
33         {
34             
35             if(i==l-n+1)
36             {
37                 tt=temp->next;
38                 temp->next=tt->next;
39                 free(tt);
40                 i++;
41                 continue;
42             }
43             temp=temp->next;
44             i++;
45         }
46         return head;
47     }
48 };