image-20220320215322894.png

    双指针

    1. class Solution {
    2.     public ListNode removeNthFromEnd(ListNode head, int n) {
    3.         ListNode dummy = new ListNode(0, head);
    4.         ListNode first = head;
    5.         ListNode second = dummy;
    6.         for (int i = 0; i < n; ++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.         ListNode ans = dummy.next;
    15.         return ans;
    16.     }
    17. }

    下周好好学习！！