p206

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LeetCode 206 Reverse Linked List 题解

1.题目：

Reverse a singly linked list.

题意：

将一个链表反转

2.解题思路:

见代码

3.代码

[title] [] [url] [link text]
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public class Solution {
    public ListNode reverseList(ListNode head) {
        if (head==null) return head;
		if (head.next==null) 
		{
			ListNode listNode = new ListNode(head.val);
			return listNode;
		}
		
		ListNode ans =reverseList(head.next);
		ListNode n =new ListNode(head.val);
		ListNode now=ans;
		for (;;)//注意循环到终点再定位next
		{
			
			if(now.next==null)
			{
				now.next=n;
				break;
			}
			now=now.next;
		}
		
		return ans;
        
    }
}

4.一些总结：