[Leetcode] Remove Nth Node From End of List

Given a linked list, remove the nth node
from the end of list and return its head.

For example,

Given linked list: 1->2->3->4->5, and n = 2.

After removing the second node from the end, the linked list becomes 1->2->3->5.

Note:

Given n will always be valid.

Try to do this in one pass.

class Solution{
public:
ListNode *removeNthFromEnd(ListNode *head, int n) {
if(!head) return NULL;
ListNode* current = head;
int count = 0;
if(n==0) return head;
while(current!=NULL)
{
current = current->next;
count++;
}

//if(n==count) return head->next;
int index = count - n;
count = 0;

ListNode* vHead = new ListNode(0);
vHead->next = head;
current = vHead;
while(count<index)
{
current = current->next;
count++;
}
ListNode *tmp = current->next->next;
current->next = tmp;

return vHead->next;

}
}