# Remove Nth Node From End of List

19. 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.

``````/**
* Definition for singly-linked list.
* public class ListNode {
*     int val;
*     ListNode next;
*     ListNode(int x) { val = x; }
* }
*/
public class Solution {
public ListNode removeNthFromEnd(ListNode head, int n) {
if (head == null) {
}

ListNode dummy = new ListNode(-1);

ListNode fastNode = dummy;
ListNode slowNode = dummy;

while (n > 0) {
fastNode = fastNode.next;
n--;
}

while (fastNode.next != null) {
slowNode = slowNode.next;
fastNode = fastNode.next;
}

if (slowNode != null && slowNode.next != null) {
slowNode.next = slowNode.next.next;
}

return dummy.next;
}
}
``````

Hope this helps,
Michael