## Question

Given a linked list, remove the $n^{th}$ 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.

## Solution

Result: Accepted Time: 0ms

Here should be some explanations.

struct ListNode* removeNthFromEnd(struct ListNode* head, int n) {
while(n--)
{

• Time Complexity: $O(n)$
• Space Complexity: $O(1)$