Interview Practice 15 – Mirror Image of Binary Tree

Question Construct 2 algorithms to make mirror image of any binary tree inputs, one of them using recursive method, another one using looping method. Mirror image means a binary tree that is the horizontal reflection of the original tree. Solution First, to do it in recursive method, we can perform pre-order traversal as usual, see preference….

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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 from your actual folder to htdocs….

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How to Take a Screenshot on BlackBerry PlayBook

To capture screen in BlackBerry PlayBook, just hold the volume Up and Down buttons together. After a camera shutter sound, a screen image in the format JPG will be saved in Pictures > Camera folder.

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Ruby on Mac OSX

In Mac, Ruby is preinstalled. You can open Terminal and input the followings to view the version of Ruby installed in your Mac [sourcecode language=”bash”] ruby -v [/sourcecode] Update Ruby. You might want to update your Ruby, however there is no installer for Ruby like Windows. Instead, we can use MacPort. Step 1. Install MacPort. You can download from…

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