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;
* next = null;
* }
* }
*/
public class Solution {
public ListNode removeNthFromEnd(ListNode head, int n) {
if(head == null ) {
return head;
}
ListNode fast = head;
ListNode slow = head;
for(int i = 0; i < n; i++) {
fast = fast.next;
}
if(fast == null) {
return head.next;
}
while(fast.next != null) {
fast = fast.next;
slow = slow.next;
}
slow.next = slow.next.next;

return head;
}
}