How to Change the Computer Name in Ubuntu

Open a terminal window. 2. At the input prompt you will see this structure: “nicholas@computer-name:~$ _ “ So you have to edit the hostname file: “sudo nano /etc/hostname “ When prompted, enter the administrator password and hit Enter. The hostname file will open, showing the current computer name. Replace the name…

Unable to install Homebrew

Unable to install Homebrew with this? ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)" What’s happened -e:70: warning: Insecure world writable dir /usr/local/bin in PATH, mode 040777 ==> This script will install: /usr/local/bin/brew /usr/local/Library/... /usr/…

Interview Practice Extra 07 - Universal Value Binary Tree

Question Design an algorithm to verify that a tree is a universal value binary tree. Universal value binary tree means all value in that tree is the same. Solution There is two approach for this problem. One is with recursive function and another is with iterative function. For this problem,…

Interview Practice Extra 06 - Vending Machine

Question This is an actual question I encountered in an Amazon phone interview in November 2013. You are going to design the money changing algorithm for a vending machine. That is, after any purchase, the machine makes change to users with a combination of coins. And the machine only have…

Tons of things working on

it’s been a while since the last post. After coming to new york, I have been very busy on my study, personal projects and (of course) playing around. studying in new york university is harsh, but not as hard as i think. I met nice people, hanged out with…

Interview Practice 02 - Stack with Minimum Function

Question Define a stack structure with “min” function — a function to get the minimum value within the stack. The time complexity of min, push and pop functions must be O(1). Solution 結合鍊錶一起做。首先我做插入以下數字: 10, 7, 3, 3, 8, 5, 2, 6 0: 10 -> NULL (MIN=10, POS=…

Interview Practice 01 - Convert Binary Tree into Doubly Linked List

Question Convert binary search tree into doubly linked list. It’s required not to create any new node, but only turning pointers. Solution The following shows the concept of this question. 8 / 6 0 -> 5 = 6 = 7 = 8 = 9 = 0 = 1 / / 5 7 9 1 First, since node…

Save Terminal from Process Completed in Mac OSX

What’s happening One day, when I opened up terminal as usual, it showed [Process completed] and just terminated. I could not type any thing, run any scripts and work on my project. Even worse, this made me unable to install programs into my computer because many installations need to…

External directory in Xampp (Apache)

For both server and website developing, I usually use Xampp’s Apache to create a localhost server. However, I hate to put my important files in the htdocs inside Apache. Instead I would rather put the folder inside Documents, and make a link to htdocs. First, create a symbolic link…