网站搭建好了怎么上到服务器医疗网站优化公司
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文章目录
- 前言
- 一、力扣92. 反转链表 II
- 二、力扣206. 反转链表
前言
一、力扣92. 反转链表 II
/*** 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 {ListNode post;public ListNode reverseBetween(ListNode head, int left, int right) {if(left == 1){return reverseN(head,right);}head.next = reverseBetween(head.next,left-1,right-1);return head;}public ListNode reverseN(ListNode head, int n){if(n == 1){post = head.next;return head;}ListNode last = reverseN(head.next,n-1);head.next.next = head;head.next = post;return last;}
}
二、力扣206. 反转链表
/*** 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 reverseList(ListNode head) {if(head == null || head.next == null){return head;}ListNode last = reverseList(head.next);head.next.next = head;head.next = null;return last;}
}