删除链表的倒数第N个结点 02.07 链表相交 142.环形链表II 24. 两两交换链表中的节点
19.删除链表的倒数第N个结点题目链接:https://leetcode.cn/problems/remove-nth-node-from-end-of-list/思路:快慢指针classSolution:defremoveNthFromEnd(self,head:Optional[ListNode],n:int)->Optional[ListNode]:head_dummy=ListNode()