public class Solution {
/**
*
* @param head ListNode类
* @param n int整型
* @return ListNode类
*/
public ListNode removeNthFromEnd (ListNode head, int n) {
// write code here
ListNode slow = head;
ListNode fast = head;
for(int i=0;i<n;i++){
fast = fast.next;
}
while(fast!=null && fast.next!=null){
fast = fast.next;
slow = slow.next;
}
if(fast == null){
return slow.next;
}
slow.next = slow.next.next;
return head;
}
}