1：题目地址

Remove Nth Node From End of List

2：解题思路

可以用Map实现，也可以用快慢指针实现

3：Java代码

  1. public ListNode removeNthFromEnd4(ListNode head, int n) {
  2.         ListNode dummy = new ListNode(0);
  3.         dummy.next = head;
  4.         ListNode first = dummy;
  5.         ListNode second = dummy;
  6.         for (int i = 1; i <= n + 1; i++) {
  7.             first = first.next;
  8.         }
  9.         while (first != null) {
  10.             first = first.next;
  11.             second = second.next;
  12.         }
  13.         second.next = second.next.next;
  14.         return dummy.next;
  15.  }

4: Go代码

  1. func removeNthFromEnd(head *ListNode, n int) *ListNode {
  2.     dummy := new(ListNode)
  3.     dummy.Next = head
  4.     //倒数第N个节点的前一个节点
  5.     preN := dummy
  6.     //记录遍历次数
  7.     i := 1
  8.     for head != nil {
  9.         if i > n {
  10.             preN = preN.Next
  11.         }
  12.         head = head.Next
  13.         i++
  14.     }
  15.     //跨过倒数第N个节点
  16.     preN.Next = preN.Next.Next
  17.     //返回链表的头结点
  18.     return dummy.Next
  19. }