Big Code - Good Code

Big Code, a Good Code? Sounds awkward? A Good code I mean here is a code which runs quicker than other solutions for the same problem.

if T(Sol1) < T(Sol2) Then, Solution 1 is a Good code., Where T is Time function , measures Time Taken

( though there are various other constraints involved, for time being let not discuss them )

Hardcore programmers are always tries to write short programs. They couple few lines of code into one and show that they have done a great coding.  But, things are not always the way it looks. Short is sweet, but not always !

Look into this code, 3 solutions for one simple problem.

Problem: Find the greatest of two numbers a, b

Million Dollar Question

Which code runs faster? If you have chosen the A’s code as faster. You have correctly made a wrong decision.

The fastest program is the B’s program. So, 3 lines of code, still fastest code? Ok.

In the A’s code,  consider if a < b, two operations should be performed.

• Compare ‘a’ , ‘b’
• Branch to Else if ‘a’ < ‘b’
• Return the expression ‘b’

But in B’s solution, we have already assigned a value to ‘x’. Only job is to compare and Assign. So the second operation is saved.

In such a small code, you won’t find a big difference. But think of a macro system with MLOC ( Million Lines of Code ).

I will explain you by solving a bit complex problem, come on join me.

Problem: Given number ‘N’ , split into ‘k’ integers, such that N = k1 + k2 + k3 +…kn and k1 * k2 * k3 is maximum.

You can try various solutions. One simple solution is

Great code, you would be proud to write one line solution of such great problem. But wait, is your code is faster to run for N > 10^10, K > 10^5?

Consider the optimize solution

More optimised

The last code works much faster than any other. Try looping it for million times with various values of ‘N & k ‘. and measure the time it takes to complete the million time execution.

How to write a speedy code?

So, this is yet another million dollar question. Take a look at the above three solutions. You will find a resemblance.

Solution - 1 is a generalized form of other two. Solution - 3 is more detailed form of Solution - 1.

So, what is been detailed in the Solution 3. If you look at more closely, you will find that Solution-3 has checks for ‘Boundary Conditions’.

Boundary Conditions are very important scenarios in any Logical System. You prove that system works perfect for boundary conditions, you prove the system to work for any values between it. Similar to Mathematical Induction. So, this applies for programming too.

If you are able to identify the boundary conditions, and make the appropriate formula for those conditions, then you will skip unnecessary computations.

We will look what have save the computational cycles.

Lets assume, the Input are N=10, K = 2

Using Solution-1:

residue = 0, mid = 5

maxProduct = Math.pow(5+1,0) * Math.pow( 5 ,(2-0) ) = 25

Operations performed:

Note: costs are just for calculation, not exact one

• Math.pow
• Addition - (5+1)
• Math.pow
• Subtraction - ( 2-0 )
• Multiplication

lets assume the cost for each operation is

Using Solution-3:

The code will branch out to the 1st if condition ( residue == 0 )

maxProduct = Math.pow( 5, 2) = 25

Operations performed

So, you have saved more than 55% of the computational cycles by covering up the boundary conditions.

So, Why you need a Speedy code?

Everyone in life loves speed. Speed bike, Speed cars ( that’s why you would love F1 ), A speedy 2 GB - Core 2 Duo Powered Machine.

Because Speed makes you feel Good !! So does a Speedy Code will be a Good code.

But, to achieve something you have to compromise with other factors, like I mentioned earlier.

If you need a 2 GB - Core 2 Duo Powered Machine, you should not consider the Money factor.

Similarly while you code, there are lot of other factors like

• Memory Management
• Security
• Transaction Isolations etc.,

This is just a introduction, will start covering up other topics soon.

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1. Change or Update Folder

Click open each feed and update the folder in which it wants to reside.

But this is just good only if you have about 10+ feeds. But as feed count goes on increasing you will find it more difficult and you might feel getting rid of the Google Reader

2. Bulk Organising

You can do bulk organising of the feeds in the settings mode.

Go to Settings -> Subscriptions, you will find all the feeds listed. This panel gives you a way to do bulk organization!

3. Quick Organising

Here is our trick that I want to explain. Google reader provides you a Drag n Drop facility to organize the feeds in the reading mode.

You keep your drag any of the feeds and move it across your folders and drop it, viola, that’s it. That’s really a faster and quick way or organising the Google Reader feeds.

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You can get the movie details for the next 3 days starting from current day.

You can make Google sort the results based on the distance, film popularity and film title. This lists down which movie is so popular and it could tell you the index of movies running in a city with the theatres

You could see google tells you which movie is so popular , so that it runs in most of theatre & multiplexes.

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But you can clear your page file while your Windows Shutdown, WINXPCPS.REG, an utility which clears the page file during the Windows XP Shutdown. This Registration (.REG) file clears the Page file when you power off the computer.

Follow these steps

1. Open Registry Editor - regedit.exe
2. Browse to: HKEY_LOCAL_MACHINE \ System \ CurrentControlSet \ Control \ Session Manager \ Memory Management
3. Add the DWORD variable “ClearPageFileAtShutdown” as dword:00000001

You are not comfortable by doing via registry hacking, you can also do it through Administrative tools.

1. Go to Control panel
2. Open Administrative tools -> local security policy.
3. Goto local policies -> security options.
4. Then change the option for “Shutdown: Clear Virtual Memory Pagefile”

Restart Windows for these changes to take effect!

Image: negativz

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How a KML structure will look like?

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.2">
<Placemark>
<name>Simple placemark</name>
<description>Attached to the ground. Intelligently places itself
at the height of the underlying terrain.</description>
<Point>
<coordinates>-122.0822035425683,37.42228990140251,0</coordinates>
</Point>
</Placemark>
</kml>

Where to get the KML parsers?

Google code provides the APIs for the KML. Also you can find the basic tutorial on KML.

Features of KML?

KML with it’s parser allows the following features to be used.

• Time and Animation
• Cameras
• Photo Overlays
• Polygons, Icons etc
• Creating Models, Regions and more.

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For the customers who buy such products, Google Adsense has issued a word of caution for the customers.

It’s been reported that the customers of the above said product would be offered a Google Adsense account on the purchase of the CDs, Presentation etc. Google verifies that they are not affliated with any 3rd party and Google doesn’t receive any payments to allow into the Google Adsense program. Google reiterate the statement,

Google Adsense is a free product offered to publishers by Google Inc.

Read more about Google Adsense and the Program policies.

Source: Google Adsense

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Windows Run command with “shell:” operator performs special operation that can’t be done via normal run commands.

I’m listing here the most useful commands using the Windows shell operator from a pile of shell operator commands.

Complete list of commands can be found here

shell:SendTo - Opens the Context menu’s SendTo folder location.
shell:Cache - Opens Internet Explorer’s temporary internet files folder.
shell:Common Desktop - Opens the Public Users Desktop folder location. C:\Users\Public\Desktop
shell:History - Opens Internet Explorer’s history of websites visited.
shell:Cookies - Opens one of the folders where Internet Explorer saves cookies.
shell:Favorites - Opens your personal username’s Favorites folder location.
shell:Fonts - Opens Vista’s Fonts folder location.
shell:InternetFolder Opens the 32 bit Internet Explorer.
shell:Links - Opens your personal username’s Links folder location.
shell:My Music - Opens your personal username’s Music folder location.
shell:My Pictures - Opens your personal username’s Pictures folder location.
shell:My Video - Opens your personal username’s Video folder location.
shell:Recent - Opens Recent Items location.
shell:RecycleBinFolder - Opens the Recycle Bin folder.
shell:Startup - Opens the location where shortcuts to programs that are set to start when Vista boots up are saved.
shell:System - Opens the System32 folder location.
shell:Templates - Opens the Templates folder location.

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I remember that it would take more than 2 days for Google to index this blog, but surprising that Google learns from the frequency of blog items from my blogs and knows the importance of indexing my blog quick.

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None of the OS is great if it doesn’t support USB & Internet. Even Leopard doesn’t get a compromise. Most of the people installed Leopard or upgraded to Leopard will face a problem where the USB drives will not be detected. I was tired of searching with Google and finally found a fix for the USB drivers to be detected.You need to install the latest drivers for USB in the leopard machine. Get it from the Apple Developer Connection - USB Debug Kits. You need to get registered in order to download it from the Apple Developer Connection.

Follow this easy step.

• Just download this zip file from drop.io - iousbfamily308.4.0
• Unzip zip it
• Install the package IOUSBFamily-308.4.0-log.pkg.
• Follow the onscreen instruction and finish the installation.
• Reboot the machine.
• Plug in the USB stick and you will find it tracked. Here is my USB stick got detected

Install the package - IOUSBFamily-308.4.0-log.pkg

Follow the installation steps.

My 4GB Trascedent USB drive mounted!

Will soon write on how to enable the Ethernet card and to handle the problems you face while you run your Leopad ( Hackintosh ).

Do you have any technical question? Drop me a mail or comment!!

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Hotmail continues it’s grip in countries like Malaysia , Ireland, Spain

As a avid Gmail user, this trend patten made me dig in to hotmail and check what is so different in hotmail.

These are the features that could make hotmail out perform Gmail.

• Outlook like Right & Bottom Pane Reading
• Unlike Gmail, Hotmail asks the user to add an Unlisted email to add into contacts. This is one feature that I like and I don’t like Gmail. Sometimes you might forget to add an address, but at the same time you might feel it handy. But this actually makes your address book like  a spam book.
• Very fast accessing of mail compared to Gmail. Just a click, you will read the mail at that instance.
• No labels, makes organizing the mails simple.

If anyone can find more reason of this pattern, please share your thoughts.

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