# [19. Remove Nth Node From End of List (Medium)](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)
<p>Given the <code>head</code> of a linked list, remove the <code>n<sup>th</sup></code> node from the end of the list and return its head.</p>
<p><strong>Follow up:</strong> Could you do this in one pass?</p>
<p> </p>
<p><strong>Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/10/03/remove_ex1.jpg" style="width: 542px; height: 222px;">
<pre><strong>Input:</strong> head = [1,2,3,4,5], n = 2
<strong>Output:</strong> [1,2,3,5]
</pre>
<p><strong>Example 2:</strong></p>
<pre><strong>Input:</strong> head = [1], n = 1
<strong>Output:</strong> []
</pre>
<p><strong>Example 3:</strong></p>
<pre><strong>Input:</strong> head = [1,2], n = 1
<strong>Output:</strong> [1]
</pre>
<p> </p>
<p><strong>Constraints:</strong></p>
<ul>
<li>The number of nodes in the list is <code>sz</code>.</li>
<li><code>1 <= sz <= 30</code></li>
<li><code>0 <= Node.val <= 100</code></li>
<li><code>1 <= n <= sz</code></li>
</ul>
**Related Topics**:
[Linked List](https://leetcode.com/tag/linked-list/), [Two Pointers](https://leetcode.com/tag/two-pointers/)
**Similar Questions**:
* [Swapping Nodes in a Linked List (Medium)](https://leetcode.com/problems/swapping-nodes-in-a-linked-list/)
* [Delete N Nodes After M Nodes of a Linked List (Easy)](https://leetcode.com/problems/delete-n-nodes-after-m-nodes-of-a-linked-list/)
## Solution 1.
```cpp
// OJ: https://leetcode.com/problems/remove-nth-node-from-end-of-list/
// Author: github.com/lzl124631x
// Time: O(N)
// Space: O(1)
class Solution {
public:
ListNode* removeNthFromEnd(ListNode* head, int n) {
ListNode *p = head, *q = head;
while (n--) q = q->next;
if (!q) return head->next;
while (q->next) {
p = p->next;
q = q->next;
}
p->next = p->next->next;
return head;
}
};
```
