Algorithm links

One of my friends was asking for resources on algorithms and here is the quick one compiled. These are the web resources apart from Art of Computer Progimming books by Donald Knuth

Peteris Krumins while preparing for google interview goes through the book Introduction to Algorithms by Thomas H. Cormen (Author), Charles E. Leiserson (Author), Ronald L. Rivest (Author), Clifford Stein (Author). Has a video of the class room and notes prepared by Peteris. As this is the blog last episode will show up first go to the last page to start from the beginning. MIT Lecture video's are good and notes help too..
Good Coder code, great use - Algorithm notes

Sorting Algorithms

Wiki link on sorting algorithms. Explanation on comparing algorithms and link to detail explanation of popular algorithms as well as some new algorithms that may not be there in the text books.

Wiki Sorting Algorithms

Searching Algorithms
Wiki link on Search Algorithms
Search Algorithms Lecture Notes from Christian Schindelauer
Skiena's Algorithms Lectures


Binary Trees
Wiki article on Binary Tree
Self Balancing Trees Red Black Tree
AVL Trees

Improving boot performance of Ubuntu Hardy Heron

After the Hardy release the boot time had increased to more than 1 min.

First I followed the Howto available at Ubuntu Forums. But this how to was created for Edgy and I had Hardy

http://ubuntuforums.org/showthread.php?t=89491

Using sysv-rc-conf altered the following.

Could not find following processes that were mentioned in the HowTo
alsa, apmd, gdomap, gpm, hdparam, hotplug and hotplug-net, hplip, ifrename, ifupdown, ifupdonw-clean, inetd, inet.real, lvm, portmap, readahead, ssh,

These were the new processes that had come after edgy
apport, atieventsd, avahi-daemon, dhcbd, hal, keyboard-setup, libpam-fo, loopback, mysql-ndb,mysql, ploicykit, powernowd, procps, rc.local, rmnlogin, rsync, vbesave

Stopped loading following based on the explaination provided in the Howto - atd, bluetooth,cupsys, dns-clean, pppd-dns
Left hotkey-setup, usplash as it is.
This changed hardly made a difference of couple of seonds. But later realized usplash was contributing to the delay and this posts suggests not to select it in the cofig.

I could not find the Boot Up manager mentioned at

http://www.zolved.com/synapse/view_content/28311/Tune_Boot-Up-Manager_for_better_performance_of_Ubuntu

Thanks to the post at

Making Ubuntu boot in 19 seconds

I found bootchart. To install bootchart run

sudo apt-get install bootchart

Bootchart creates png image of boot activities at /var/logs/bootchart From bootchart I found that usplash was using CPU during the Boot. More the CPU taken up the process the bar will have darker shade of the blue.

Fixed the issue as per the thread

http://ubuntuforums.org/showthread.php?t=285920&page=3

Edit usplash.conf and set resolution to 1024x768. Though actual resolution of my screen is 1280x800 that makes splash and text move to the left.

sudo gedit /etc/usplash.conf

Once this is set reconfigure the usplash package or run the below command to update the theme. You can notice the additional parameter vga=773 in /boot/grub/menu.lst after you have run this.

sudo update-usplash-theme usplash-theme-ubuntu

After this boot time was reduced to 32 seconds and my splash screen also started working. Earlier I used to get a blank screen during boot and I was thinking thats how it works!

There is a startup-manager available to handle manage Grub configuration.

Japanese Learning tools on Ubuntu

I am finding these 2 tools very useful in learning Japanese.

Kanatest helps you to sharpen Hiragana and Katakana including the mixed kana. Randomly a letter is shown and user has to give the romaji equivalent of the symbol. One can also track the progress by the history of tests which contains time taken and percentage of correct answers. For installaing it run

sudo apt-get install kanatest

Langdrill has similar features and also contains vocabulary lessons. Apart from Japanese it contains drills for French and Swedish. For installing

sudo apt-get install langdrill

For more tools visit mbrass