题解 | #反转链表#
反转链表
https://www.nowcoder.com/practice/75e878df47f24fdc9dc3e400ec6058ca
using System; using System.Collections.Generic; /* public class ListNode { public int val; public ListNode next; public ListNode (int x) { val = x; } } */ class Solution { /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param head ListNode类 * @return ListNode类 */ public ListNode ReverseList (ListNode head) { // write code here //解题思路:从头结点读取,然后用头插法逐个插入读取的元素 //新头结点 ListNode node = new ListNode(-1); while (head != null) { //新结点 var temp = new ListNode(head.val); //新结点的引用域指向新头结点的引用域 temp.next = node.next; //新头结点的引用域指向新结点 node.next = temp; head = head.next; } //返回头结点的引用域 return node.next; } }