链表篇

思路：

先走一遍记录链表长度

再走到对应的点，然后删除

/*** 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) {//哨兵节点ListNode dummy =new ListNode(0,head);int length=0;ListNode temp=head;while(temp!=null){length++;temp=temp.next;}ListNode cur=dummy;for(int i=1;i<length-n+1;i++){cur=cur.next;}cur.next=cur.next.next;return dummy.next;}
}