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reverse-linked-list

Posted on Edited on

Add Binary – LeetCode 206

Problem

Description

Reverse a singly linked list.

Answer

Original

Code

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/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode *prev = nullptr;
        ListNode *curr = head;
        while(curr){
            ListNode *next = curr->next;
            curr->next = prev;
            prev = curr;
            curr = next;
        }
        return prev;
    }
};

思路

简单的循环翻转next指针，时间复杂度$O(n)$，空间复杂度$O(1)$。
耗时$6$ ms，排名$40.32\%$

Better

思路

没看到更好的思路。