Maximum Depth of Binary Tree Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node. Show Tags Tree Depth-first Search 没啥说的，深度优先搜索(Depth-first Search)，直接在网站上敲代码，一遍AC。 /** * Definition for binary tree * struct […]
Find Peak Element A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠ num[i+1], find a peak element and return its index. The array may contain multiple peaks, in that case return the index to any one of the peaks is […]
Intersection of Two Linked Lists Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: A: a1 → a2 ↘ c1 → c2 → c3 ↗ B: b1 → b2 → b3 begin to intersect at […]
Merge k Sorted Lists Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Tag: divide and conquer, linked list, heap update 9/22/2015 Merge sort the k lists. O(knlogk) in time, O(1) //merge these /** * Definition for singly-linked list. * struct ListNode […]
Swap Nodes in Pairs Given a linked list, swap every two adjacent nodes and return its head. For example, Given 1->2->3->4, you should return the list as 2->1->4->3. Your algorithm should use only constant space. You may not modify the values in the list, only nodes itself can be changed. […]
Best Time to Buy and Sell Stock II Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell […]
Description: Best Time to Buy and Sell Stock Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design […]
type ls -al in the terminal Privilege: There are 10 bits in privilege part. bit 1: [d] – directory [-] – file [l] – link file [b] – interface devices [c] – serial port devices, such as mouse, keyboard bit 2-4: privilege of the file owner. read, write and execute […]
Device Name In Linux, all the devices are treated as files that are stored in /dev directory. For example, IDE disks are saved as /dev/hd[a-d] SCSI/SATA/USB disks are saved as /dev/sd[a-p] USB devices are saved as /dev/sd[a-p] (same as SATA disks) Partition Table Partition Table lies on the first sector […]
2015.1.30 星期五 小雨转雪转雨夹雪 好久没写日记了，今天补上。 最近挺忙的，接了一个创业项目的活，写APP的后端。应该说，这是我见过的最靠谱的项目了。BOSS从贝恩离职，转而自学代码，开发社交APP。他写iOS的前端，我和邹与另一位中学老师写后端。三四天的样子，基本开发完成。 第一次参加团队项目，有趣的是，四人开发团队中，我在Linux下开发，两个是MAC，一个是WIN。经常发生的事就是，WIN的那位兴致冲冲地说，“喂，我找到了一个非常棒的插件！”然后他给我们群发过来，发现是.exe或.dll。顿时哭笑不得。又或者，写了中文注释，结果因为编码不同导致在另一人的机器上出现乱码。WIN下默认是GBK编码，而Linux下是UTF-8，MAC下我不清楚。 但是在开发过程中，发现了SVN/GIT这样的版本控制工具的优势；以及Linux在编程方面的优势。感觉编程工具方面，比如数据库，服务器等，都是现在Linux下出现，而后再移植到WIN货MAC下，所以Linux天生就有编程的优势，环境也很好搭，不需要安装第三方库。 BOSS送了个机械键盘，还是很不错的款。自己选了红轴、无背光。刚到了货，用起来感觉不错。 2015.1.21 星期三 晴 今天没刷Leetcode,而是在装Linux.DIY Boot Loader. 内核和grub装在U盘里,其他文件装在磁盘里.自定义一个脚本,开机后把U盘弹出.并在Windows下隐藏Linux的分区.U盘就像一个钥匙,有了它才能打开Linux.好棒的点子!不行太兴奋了,今天学到很多知识.内核\电脑启动\MBR\Boot Sector\Boot Loader\grub2\… 2015.1.20 星期二 雨 找班主任聊四轴飞行器。班主任是航院，更偏重于结构的设计，硬件。我想自己的毕设还是偏重于软件，算法的撰写。飞行器里跑的竟然不是Linux。原想利用Linux的知识写些很酷的东西。 TODO： 找那两位学生，聊入门，教程。 找卜老，聊毕设。 看看有没有quadcopter里面跑Linux的情况。 约了卜老，准备见面聊聊。刷Leetcode爽得飞起，但感觉总体难度不是很大。可能是还没遇到难题吧。学STL，每天过的很充实。又找到了奋斗的动力。 U盘返到京东修理了，明天换一个新的过来，赞京东。 2015.1.19 星期一 晴 U盘又坏了，把Linux装在U盘里，玩坏了两块U盘了。寄回京东返修，不知要等多久。暂时把Linux放一放。 开始刷Leetcode，一下AC了三道题还是挺爽的。第四道题hard，heap和divide and conquer还不清楚，卡住了。准备好好复习数据结构和heap的知识。尤其是时间复杂度的估算。 明天找班主任咨询四轴飞行器的事情。 2015.1.14 Wednesday Sunny I’m on my Linux. So English this time, though its terrible. Be […]
