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…

Mbox Mail for Mac is actually working on Lion

Once I thought the Mbox Mail for Mac doesn’t work in Lion. The reason is that when I use the same setting in Thurderbird, i can receive emails. This made me ensure the problem comes from the new Apple Mail 5. I dug into the protocol IMAP, learnt the…

Convert character encoding in PHP

Usually while we extract information from other websites, character encoding might not correct. For example, j-jis.com is encoded with Shift-JIS. Therefore if your MySQL charset is UTF-8, it causes incorrect information. To handle the changing of character encoding, we can use iconv in PHP. [sourcecode language=”php”] $url = "…