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.

public class Solution {
    public ListNode removeNthFromEnd(ListNode head, int n) {
        //Time: O(n)  Space: O(1)
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        head = dummy;
        
        ListNode fast = head;
        ListNode slow = head;
        for (int i = 0; i < n; i++) {
            fast = fast.next;
        }
        
        while (fast.next != null) {
            fast = fast.next;
            slow = slow.next;
        }
        slow.next = slow.next.next;
        return dummy.next;
    }
}