/** * Definition for singly-linked list. * public class ListNode { *     int val; *     ListNode next; *     ListNode() {} *     ListNode(int val) { this.val = val; } *     ListNode(int val, ListNode next) { this.val = val; this.next = next; } * } */class Solution {    public ListNode removeNthFromEnd(ListNode head, int n) {        ListNode realHead = new ListNode(0, head);        ListNode fast = realHead;        ListNode slow = realHead;         int i = 0;        while(fast != null){            if(i <= n){                fast = fast.next;                i++;                continue;            }            fast = fast.next;            slow = slow.next;        }        slow.next = slow.next.next;         return realHead.next;    }}