# 19. Remove Nth Node From End of List (Medium)

https://leetcode.com/problems/remove-nth-node-from-end-of-list/

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

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.

Could you do this in one pass?

## Solutions

``````class Solution {

public ListNode removeNthFromEnd(ListNode head, int n) {

int count = 0;
while (count < n) {
ptr1 = ptr1.next;

// if n >= the length of given list, return the node next to head
if (ptr1 == null) {
}

count++;
}

// To reach here, the reversed nth node can't be the head node

// Move one more step, now ptr1 is at node n + 1.
ptr1 = ptr1.next;

// ptr1 moves x-n-1 steps to reach the end. At the same time, ptr2 move x-n-1
// steps from the head, the index becomes x-(x-n-1)=n+1 counting from the tail. It's
// easy to get the nth node in reverse order which is the next value of node
// n+1(reversed index).

while (ptr1 != null) {
ptr1 = ptr1.next;
ptr2 = ptr2.next;
}

ptr2.next = ptr2.next.next;