題目描述

輸入一個連結串列，反轉連結串列後，輸出新連結串列的表頭

題目連結：https://www.nowcoder.com/practice/75e878df47f24fdc9dc3e400ec6058ca

解題思路

思路1：藉助棧

思路2：遞迴

思路3：連結串列原地反轉

public class Solution {
    public ListNode ReverseList(ListNode head) {
        if (head == null || head.next == null) return head;
 

        ListNode pre = null;
        ListNode next = null;
        while (head != null) {
            next = head.next;
            head.next = pre;
            pre = head;
            head = next;
        }
        return pre;
    }
}