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…

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…

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}. 快慢指针找到链表中点,将链表分为两段,翻转后半段,再合并两个子链表. /** * Definiti…

这道题是LeetCode里的第937道题. 题目描述: 你有一个日志数组 logs.每条日志都是以空格分隔的字串. 对于每条日志,其第一个字为字母数字标识符.然后,要么: 标识符后面的每个字将仅由小写字母组成,或: 标识符后面的每个字将仅由数字组成. 我们将这两种日志分别称为字母日志和数字日志.保证每个日志在其标识符后面至少有一个字. 将日志重新排序,使得所有字母日志都排在数字日志之前.字母日志按字母顺序排序,忽略标识符,标识符仅用于表示关系.数字日志应该按原来的顺序排列. 返回日志的最终顺序.…

问题的思路是这样: 循环取头部合并,事实上也能够换个角度来看,就是将后面的链表结点,一次隔空插入到第一部分的链表中. class Solution: # @param head, a ListNode # @return nothing def reorderList(self, head): if None == head or None == head.next: return head #找到中间点,截断 pfast = head pslow = head while pfast.next…

[LeetCode]143. Reorder List 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/reorder-list/description/ 题目描述: Given a singly linked list L: L0→L1→-→Ln-1→Ln, reorder it to: L0→Ln…

[LeetCode]Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. 递归和非递归,此提比较简单.广度优先遍历即可.关键之处就在于如何保持访问深度. 下面是4种代码: im…

Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could you optimize your algorithm to use only O(k) extra space? 思路:最简单的方法就是依照[Leetcode]Pascal's Triangle 的方式自顶向下依次求解,但会造成空间的浪费.若仅仅用一个vect…

53. Maximum Subarray[leetcode] Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2,1,-3,4,-1,2,1,-5,4],the contiguous subarray [4,-1,2,1] has the largest sum = 6. 挑…