链表倒数第k个节点

 public ListNode FindKthToTail(ListNode head,int k) {
            ListNode quick=head,slow=head;
        if(head==null||k==0) return null;
        while(k-->1){
            if(quick.next==null) return null;
            quick=quick.next;
            
        }
        while(quick.next!=null){
             quick=quick.next;
             slow=slow.next;
        }
        return slow;
    }