一.题目描述 Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes' values. For example,Given {1,2,3,4}, reorder it to {1,4,2,3}. 二.分析 1.暴力解法 这种解法所需的时间的时间复杂度比较高,为O(n2) 代码如下…

Reorder List 题解 原创文章,拒绝转载 题目来源:https://leetcode.com/problems/reorder-list/description/ Description Given a singly linked list L: L0?L1?-?Ln-1?Ln, reorder it to: L0?Ln?L1?Ln-1?L2?Ln-2?- You must do this in-place without altering the nodes' values. For…

You have an array of `logs`.  Each log is a space delimited string of words. For each log, the first word in each log is an alphanumeric identifier.  Then, either: Each word after the identifier will consist only of lowercase letters, or; Each word a…

Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes' values. For example,Given {1,2,3,4}, reorder it to {1,4,2,3}. 思路: 先把链表分成两节,后半部分翻转,然后前后交叉连接. 大神的代码比我的简洁,注意分两节时用快…

Given a singly linked list L: L0→L1→…→Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes' values. For example, Given {1,2,3,4}, reorder it to {1,4,2,3}. 解题思路一: 每次将Ln换到前面,得到L0→Ln→L1→L2→L3→,然后对L1使用相同操作,…

Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring. 解题思路一: 暴力枚举 共N^2量级个子串(从下标零开始),每次检查需一个for循环,等于是3重for循环,时间复杂度O(n^3) 解题思路二: 动态…

Given a singly linked list L: L0→L1→-→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→- You must do this in-place without altering the nodes' values. For example,Given {1,2,3,4}, reorder it to {1,4,2,3}. 按照题意改变链表结构. 1.使用list记录链表. /** * Definition for si…

For example,Given {1,2,3,4}, reorder it to {1,4,2,3}. /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: void reorderList(ListNode *head…

Given a singly linked list L: L0→L1→-→Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→- You must do this in-place without altering the nodes' values. For example, Given {1,2,3,4}, reorder it to {1,4,2,3}. /** * Definition for singly-linked list. * clas…

→-→Ln-1→Ln, reorder it to: L→Ln-2→- You must do this in-place without altering the nodes' values. For example, Given {1,2,3,4}, reorder itto {1,4,2,3}. Considering the following steps:  * 1. split such list into two list, first and second, according…