`Coding Voding`

How to screw your telephonic interview in five simple ways !!

2011-05-18T12:33:00.000-07:00

Having three telephonic interviews experience, all being unsuccessful, I consider myself as the master of my group. Ya, the group of people who are good at screwing up their interviews. Wanna join this elite group ? You just need to take the below mentioned five easy steps before and during the telephonic interview as required.

The five glorious steps:

As per the procedure of the interview, the HR of the company calls up the student (to be interviewed) for the first time. Aim of HR is to convey student the interview timings, confirm his phone number and get aquainted to his background. The blunder you can do at this time is not to ask about the type of questions you would be asked during the interview. If you didn't do that.. you just took first step to join my elite group ! Certain companies (like facebook) prefer asking the algorithm questions (just like those in programming contests) whereas other companies (like Magma Inc. and Directi) check student's logic and reasoning by asking puzzles.

The second blunder you can do is to consider yourself superman and not prepare anything for the day. Do not even bother to look upon previously asked questions by the company or get yourself aquainted with famous puzzles asked during interviews.

You'll be just two steps away if you don't charge the mobile enough for an hour long interview on the death day.

The second last blunder you can do is to choose such a place for the interview where you get the weakest mobile signal as in casually lying in your bedroom and getting the call with no ear phones or your bathroom so that none of your friend sees you or hears your conversation !!

The last but not the least blunder you can do is to get fumbled up in nearly all the questions asked. Push the panic button again and again. Beat around the bush, don't hit the point and make the interviewer furious over you.

Ok, ya I m a little too agitated about another failed telephonic interview. The point is you can read the five steps, exactly do the opposite and make you interview much more comfortable and impressive.

* * * * *

Algothematics.. back again !!

2011-03-08T23:44:00.000-08:00

Algothematics is back.. smarter and trickier !! Algothematics was first introduced in Zealicon '10 (annual TechFest of JSS Academy of Technical Education, Noida) and is slated for 9th March in Zealicon'11. Just as the last year, the event will be conducted online. All programmers across the world are, hence, invited.

Rules are the same. The event comprises of 15 levels. Each level has an ad-hoc mathematical problem which can either be solved manually (using pen and paper) or by conceiving certain algorithm. The submission requires only the answer to the question. Submission of source-code is not required.

Other tools can also be used for solving the problems. Spreadsheet, PARI-GP, MATLAB or anyother library (like BigInteger) are among them. Besides all these we always have GOOGLE with us... :)

Besides all this, Zealicon forum will contain an "Algothematics" thread under "online events" where all sorts of problems and their hints will be discussed. No questions extraneous to the event will be entertained.
LeaderBoard will be available at the home page itself, so that you can constantly check your position among others.

Please do not ruin the basic purpose of event by any hacking stuff. Those not conforming to the rules and regulations will be banned without prior information. Decision of Algothematics Team will be the last.

First two teams reaching the final level will be adjudged victorious..

So pull up your socks, hone your programming skills.. Algothematics is about to begin..!!! (9th March, 20:00)

* * * * *

Getting started with USACO

2011-02-05T10:41:00.000-08:00

USACO (or United States of America Coding Olympiad) is a programming competition primarily for students in USA. It allows codes to be written in c, c++, java and pascal programming languages. There are currently three divisions of the USACO: Bronze (easiest but requires some programming ability), Silver, and Gold (hardest). Participants advance through the divisions by performing well in their current division, or in a qualifying round.

Training pages, internet competitions, US Open ( please don't confuse it with the grand slam :P ) form the basic three parts of USACO. Of these three - training pages are of our interest. These pages are designed to develop one's skills in programming solutions to difficult and varied algorithmic problems at one's own pace. In addition to around several problems, there are texts on programming techniques such as greedy algorithms, dynamic programming, shortest path and many more. Enthusiasts find the training pages so useful that people from other countries use them to prepare for their own national or international level competitions. Amazing thing is that today the coders from other countries have out numbered the US participants !! :P

For getting started with USACO you can register by clicking here. After the registration you can begin with the chapters and corresponding sections through the USACO gateway. The submissions at USACO must conform by following rules:

All solutions must have a header as follows:

ID: YourId

PROG: the name of program which will be provided in the problem statement itself

LANG: preferred language

The input needs to be read from a file named PROG.in (PROG refers to name of the program as mentioned in header) and output written onto another file named PROG.out.
The output file must have a whitespace at the end else it will not compile.

Here's my solution to a problem named Dual Palindromes:


/*

ID: vaibhav4

PROG: dualpal

LANG: C++

*/

#include<fstream>

#include<iostream>

using namespace std;

int isPal(string a)

{

 int i,j;

 for(i=0,j=a.size()-1;i<j;i++,j--)

     if(a[i]!=a[j]) return 0;

 return 1;

}

string conv(int decimal, int base)

{

 if(decimal == 0) return "0";

 char NUMS[] = "0123456789ABCDEFGHIJ";

 string result = "";

 do

 {

     result.push_back(NUMS[decimal%base]);

     decimal /= base;

 }while(decimal != 0);



 return string(result.rbegin(), result.rend());

}

int main()

{

 ifstream cin("dualpal.in");

 ofstream cout("dualpal.out");

 int s,n,i,count=0,count1=0;

 cin>>n>>s;

 s++;

 while(count!=n)

 {

     count1=0;

     for(i=2;i<=10;i++)

     {

         if(isPal(conv(s,i)))

             count1++;

         if(count1>=2)

         {

             cout<<s<<"\n";

             count++;

             break;

         }

     }

     s++;

 }

 return 0;

}

Hope it's now easy to get started with USACO..

Happy Coding !!

* * * * *

an ACM experience

2011-01-06T05:09:00.000-08:00

..and finally we disembarked at Kanpur.

Competing at the world's most prestigious programming event (even at the regional level :P ) looked just like a dream earlier but not any more. On 11th of December 2010, we were on our way to IIT Kanpur for competing with some of the best coders of this country. We were (Team name: Elites) amongst the top 50 teams of Northern India who were invited to participate at the ACM regional level after qualifying the prelims, which was held earlier amongst more than 200 teams.

On reaching the campus we were greeted with two goody bags. One was from ACM itself and the second came from Directi, the official sponsers of the event. Goody bags were loaded with some really good stuff ranging from T-shirts, diaries to pens and badges. Great hospitality, awesome management and top-class environment at IIT Kanpur were the things they can really boast about.

On 12th December the teams competed for five hours. There were ten problems given. By the end, we managed to solve three problems (and managed to win three pen drives !!! :P ). The team from Indonesia (Dongskar Pedongi) came first solving eight questions whereas team from IIIT Hyderabad (Any Dream) came second solving seven probelms. The team from Hyderabad included Yash Kumar and Nadeem Moidu, who held the second and fifth position in the AOL CodeDash competition too.

But the team that made it to Egypt (for world finals) was from IIT Kanpur (Deep thought). I would like to further elaborate details about the team members. The team consisted of three members:

Raziman TV, who is a blogger and you can visit his blog "Mistranslated" here. He has won many such events both at the regional and the world level. The entire achievements list of Raziman can be seen here. Now possibly he has one more achievement of ACM to brag about!! :D

Shitikanth was the second member. He topped the IIT-JEE 2008 examination (AIR-1). He is a regular codechef member too.

Utkarsh Lath is also a codechef member and much higher placed than his colleague Shitikanth.

With such great coders IIT Kanpur really deserved to win the world finals berth.

Later in the prize distribution ceremony, I was pleased to see my friend Rahul Gulati (Team name: HyperHexagon) secure the tenth place. We (with Prateek Gupta and Ankit Jain as my team-mates) were amongst the honourable mentioned ones as we managed to solve more than one question. With more than half a dozen of certis we bid IIT Kanpur adieu.

Summing up the entire event.. it was really an amazing ACM experience.. :)

* * * * *

My Stackoverflow Badge

2010-09-26T07:54:00.000-07:00

This is my Stackoverflow badge. Stackoverflow, as most of you would be knowing, is a website part of the Stack Exchange Network featuring questions and answers on a wide range of topics in computer programming.

I have earned these many points asking questions and posting some quality answers on topics ranging from c/c++ programming, asp. net, Eclipse and Android.

* * * * *

My Project Euler Badge

2010-09-07T13:35:00.001-07:00

Above is my Project Euler Badge. It shows my username and the number of questions I have solved. It keeps on changing dynamically.

* * * * *

Getting started with Linux File System

2010-08-21T12:40:00.000-07:00

via my friend Prateek Gupta ...

For those of you coming from windows background, the way the linux filesystem is laid out may seem confusing at first glance…. but that is where this article comes in !

The first thing you should know when working with linux, is that everything is treated as either a file or directory. Yep thats right, even hardware is considered a file by linux, and, speaking of hardware… all your hardware devices are located in the /dev directory, but more on that... later.

Another thing that confuses windows users, is the fact that linux dosen’t use drive letters to distinguish between different partitions and devices. that is to say in linux, the “root” of your filesystem is / whereas in windows it would most probably be C:\ . Drives in linux are “mounted” to directories where their data can then be accessed, so for instance, if you needed to use your thumbdrive, you would plug it into your computer, and then mount it using the “mount” command, which specifies the path to the device ( something like /dev/sdb or /dev/sdc ) and the directory to mount it to (usually /mnt or /media), then you can happily access your drive from the /mnt or /media folder.

Sounds strange right? well yes it does if you come from a windows environment, where the entire operating system is consolidated onto a single drive. However, with linux and the ability to mount devices as directories, it gives the end user much greater flexibility in splitting up their operating system over several drives or partitions.

To understand what I mean when I say that this approach in mounting drives grants flexibility, I must first explain the different folders in linux and what they store / this is the root folder, all other folders come under root.. think of it as C:\ in a Windows context.

/bin this folder contains all the user-essential binaries (programs) that are needed to administer and run your linux system… delete this folder and your system is broken.

/boot as the name suggests, this folder contains configuration files and other necessary files that are needed by the bootloader

/dev this folder contains device files (remember, these files represent physical devices, so be careful when working with them)

/etc this folder contains all the configuration files used by the system, you can also start and stop services (daemons ) from here

/home this folder contains the home folders of all the normal (non – root ) users on the system .. think of it as my documents in windows

/lib this folder contains software libraries

/media this is a mount point for removable devices… this is where you would usually mount your thumbdrives … etc

/mnt this is a temporary mount point

/opt this folder contains add on software (extra software)

/sbin this folder contains binaries that can only be run as the root user (”superuser”)

/tmp this folder contains temporary files that are erased upon reboot

/usr this folder and its subfolders contains user installed programs and utilities and libraries

/var this folder contains files that change alot (”Variable files”)

/root this folder contians the root user’s files

/proc this is a psuedo folder, that contains information about the linux kernel and hardware that is updated in realtime.

Now back to how mounting grants flexibility…

You see, how the different folders all contain parts of the operating system? Well we can actually mount a seperate hard drive for each of this folders. for example, your /home folder can be put on another harddrive than your / which means that you can easily recover your personal files if the harddrive on / fails because the harddrive mounted to your /home folder is seperate from the one that is mounted to your /

So there you have it, you now know a lttle bit more about the nuts and bolts of linux based operating systems.

* * * * *

My Android Applications

2010-07-25T05:41:00.000-07:00

During the summer internship I learned about interesting and innovative work of Android Application Development. I have already posted about getting started with it and some important links in my earlier posts. In this post I m going to discuss some of the applications I built.

Info Displayer:

Info displayer is a simple and light application. No doubt, it was my first app :). The application fetches some important information about your Android Device, such as, the device number, the hardware, the Manufacturer, Product, Model, Time etc. The application used "build" library and its functions to fetch the information.

Webber:

Webber claims to be the world's simplest browser. It just has a text box to write a URL and the view below it, which fetches the web-page. It doesn't allow the default browser to hinder its working. I used an EditText and a WebView to present this app. Other stuff was just a cake walk.

Sleek Feed:

Sleek Feed is an application that displays the feeds of the saved URL. The application parses the XML file, and gets the titles of the latest feeds and displays it onto the screen. The URL is feeded by the user himself through the admin panel. The main feature of the application is the fact that it saves the previous URL feeded in the admin panel.

To view its complete working see the video here on youtube.

One thing I learned while building these apps that "it's not knowledge, but it's innovation, that matters a lot while completing an entire project."

* * * * *

Some useful links for building Android Apps

2010-07-15T07:38:00.000-07:00

Working on Android Application Development I came across some very useful links that every Android App Developer must follow. Here is my "Delicious.com" account, you can look for all the bookmarks I have saved.

In this post I am recommending some of the important Android forums and websites. By this time you must obviously be familiar with the official Android Developer Website where you can find the entire documentation of the project. Do add yourself to the Android Google Group for asking all your queries. For hosting your applications access its Official Marketplace.

Besides these regular sites which everyone accesses, I m here to share some more websites that can help novice get started and go on further with the Android App development.

(Click the titles for opening the pages)..

Getting started:

Here's Lars Vogel with his tutorial for getting started with Android App Development. Besides getting started, it also teaches to build a hello world app, demonstrates how to build menus and work with preferences, a nice content provider example and how to make a file browser. At last it demonstrates how to deploy your app onto a real device.

Marakana Tutorials:

This is one of my best recommendations. Some very nice demo projects are hosted on the site. Studying Motto Twitter project can help understand the concepts in depth. Certain API's have also been explained in the tutorials. The use of bluetooth and camera may become very clear refering to their API tutorials.

Androidians:

Nice tutorials by Nithin Warreir. The blog contains some code snippets that help during development of big projects. One can learn implementation of various tools of Android development easily here. I have even added the admin to my gmail contacts and regularly ask him to review my applications.

Android Forum:

Anddev forum is pretty famous for having a large number of online users everytime. For any query you can easily post a question in this forum. Wait for the help that comes in just a few minutes. One can also use the android tag of Stackoverflow, but mind you, it's lame..!! Too slow responses and you'll end answering your own question later which doesn't contribute to the repo at all.. :P

SlideME Android Market Place (Free for developers):

Besides the Official Marketplace, this is another marketplace that hosts developer's applications. For registering as developer in the official marketplace, one needs to pay $25, here lies the advantage of joining SlideMe, it is free..!!

Register yourself and deploy all your apps. The apps may be free or paid. The paid apps can only be downloaded from Android Phone through SlideMe market app. The website asks for copies of your project's ".apk" file and forms an inventory and on downloads you need to generate an invoice to redeem the money. Here is link for viewing my apps.

Happy developing ;)

* * * * *

Getting started on Android Application Development

2010-06-02T11:06:00.000-07:00

Working as an intern at webkul, I set up Android on my PC. Here's the entire documentation I submitted.

Simple Steps for getting started with the Android Application Development on Windows:

Step-1: Downloads

Download the Eclipse IDE for Java EE Developers (it's 163 MB). (http://www.eclipse.org/downloads)
Download the Android SDK. Once the SDK is downloaded, unzip the SDK into a folder.

Step-2: Configure Ellipse

Start Eclipse
Goto to Help->Install New Software.
Hit Add.
For the name, type “Android” and set the link to “https://dl-ssl.google.com/android/eclipse/” (if this doesn’t work, try it with http:// instead of https://).
Click OK.

Step-3: Add ADT (Android Development Tools)

Download the tools from http://developer.android.com/sdk/index.html

Step-4: Configure Android SDK

Start SDK Setup.exe.
Install all the packages needed.
SDK Manager installs the tools.

Step-5: Set up Android Virtual Device

Click on Virtual Devices in SDK Manager.
It creates an Android device that will test run the programs.
In the name field: “any name”
In target field: “Android 2.2 – API Level 8”
Select Size as 20.
Hit create.
Select AVD from list
Hit Start

Step-6: Configure Eclipse again

Open Eclipse
Goto Window->Preferences
Select the Android tab.
Browse to the location of your Android SDK
Hit Apply.
Hit OK.

Step-7: Create a new Project

Goto File->New->Projects
Select Android Projects.
Fill the required fields.
Hit Finish
Start Coding.

Step-8: Run Your Program

Press F11.
Hit Save.

* * * * *

Google Code Jam - 2010

2010-05-26T01:51:00.000-07:00

It was during GCJ 2009 when I got myself more involved in coding stuff. I still remember my last year's post about my performance at GCJ 2009. I can happily and proudly say that yes this year I showed some improvement..!!

Qualification Round:

The round started early morning and made me code even when the semesters were approaching..!! Nevertheless I went on for the third problem (Theme Park) first as it seemed much easier than others. Here's my code which I submitted for the correct submission.

#include<iostream>
#include<fstream>
#include<sstream>
#include<vector>

using namespace std;

int main()
{
   int t,i,e=0,c=0,r,k,n,x,ans=0,flag=0,j,m=0;
   vector<int> a,f;
   ifstream fin("C-small-attempt0.in");
   ofstream fout("output.in");
   //ofstream fout("output.in");
   fin>>t;
   //cout<<t<<"\n";
   while(t--)
   {
       m++;
       ans=0;
       e=0;c=0;
       a.clear();
       f.clear();
       fin>>r>>k>>n;
       for(i=0;i<n;i++)
       {
           fin>>x;
           a.push_back(x);
       }
       i=0;
       while(e!=r)
       {
           e++;
           c=0;
           f.clear();
           flag=0;
           while(c<=k)
           {
               if(i>=a.size()) break;
               c+=a[i];
               if(c>k) break;
               else
               {
                   f.push_back(a[i]);
                   ans+=a[i];
                   i++;
               }
           }
           for(j=0;j<f.size();j++)
               a.push_back(f[j]);
       }
       fout<<"Case #"<<m<<": "<<ans<<"\n";
   }
   return 0;
}

The code didn't suffice for the large test cases and I switched my attention to the first problem. After finding the logic of the problem it was a cake to write the code which even survived the large test cases and made our way to round-1 clear. Here's the code for problem-1 (Snapper Chain)


#include<iostream>
#include<fstream>
#include<math.h>

using namespace std;

int main()
{
   int t,n,k,c,s,m=0;
   ifstream fin("A-small-attempt1.in");
   ofstream fout("output1.in");
   fin>>t;
   while(t--)
   {
       m++;
       fin>>n>>k;
       c=pow(2,n)-1;
       if(k<c)
       {
           fout<<"Case #"<<m<<": "<<"OFF\n";
           continue;
       }
       else
       {
           s=c;
           while(s<k)
           {
               s+=(c+1);
           }
           //cout<<s<<" "<<k;
           if(s==k)
               fout<<"Case #"<<m<<": "<<"ON\n";
           else
               fout<<"Case #"<<m<<": "<<"OFF\n";
         
       }
   }
   return 0;
}

With 43 points I advanced to Round-1.

Round-1C

I was unable to code in round 1A and round 1B due to the sixth sem examination. Nevermind, I got my chance to survive in the last round. I successfully submitted the problem-1 (Rope Intranet) (both large and small datasets) for 22 pts. My code:

#include <iostream>
#include <fstream>
#include <algorithm>
#include <string>
#include <sstream>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <queue>
#include <deque>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <math.h>
#include <cctype>
#include <iterator>
#include <utility>

using namespace std;

int main()
{
   int m,t,ans,i,j,n,a,b;
   vector<int> b1,b2;
   ifstream fin("A-small-attempt0.in");
   ofstream fout("o.out");
   fin>>t;
   for(m=1;m<=t;m++)
   {
       ans=0;
       fin>>n;
       for(i=0;i<n;i++)
       {
           fin>>a>>b;
           b1.push_back(a);
           b2.push_back(b);
       }
       for(i=0;i<b1.size();i++)
       {
           for(j=0;j<b1.size();j++)
           {
               if(i==j) break;
               if((b1[i]<b1[j])&amp;&amp;(b2[i]>b2[j]))
                   ans++;
               else if((b1[i]>b1[j])&amp;&amp;(b2[i]<b2[j]))
                   ans++;
           }
       }
       b1.clear();
       b2.clear();
       fout<<"Case #"<<m<<": "<<ans<<"\n";
   }
}

Problem-2 (Load Testing) was really hard to understand and so was problem-3. After the competition ended I found myself placed at 1,950th position and losing the match by 950 ranks. Here's my complete performance.. GCJ-2010.
Khair, m happy but not satisfied. Will definitely improve the next time. Waiting for GCJ-2011 desperately..!! :)

* * * * *

Getting started with Programming Contest Control (PC2)

2010-03-29T23:29:00.000-07:00

After a grand success of JSSATEN techno-cult fest Zealicon '10, I wanted to redirect myself to blogging. So, here I m with another post in which I would like to share my experience with Programming Contest Control (PC2) software.

PC2 is a dynamic, distributed real-time system designed to manage and control Programming Contests. PC2 operates using a client-server architecture. Logging into a client using one of several different types of PC2 accounts (Administrator, Team, Judge, or Scoreboard) enables that client to perform common contest operations associated with the account type, such as contest configuration and control (Administrator), submitting contestant programs (Team), judging submissions (Judge), and maintaining the current contest standings (Scoreboard).

Here are the steps to begin with PC2 software:

Install Java (version 1.3.1 or greater).
Donwnload PC2 software from here ( I prefer version 8 ).
Edit the pc2v8.ini file to point servers and clients to the server IP:port and put the modified .ini file on every server and client machine.
Start a PC2 server by running “pc2server.bat” and answer the prompted question as "no".
Start a PC2 Admin client by running “pc2admin.bat” and login using the name “root” and password “root”.
Do not forget to change the username and login after that.
Configure the Admin.
Admin: Generate the number of teams, judges, admins, scoreboards you need.
Admin: Add the problems from the problem tab.
Admin: Define the languages allowed in your competition from the language tab.
Admin: Configure the clock from the Time/Reset tab. You can start and stop the contest from this tab.
Start all PC2 Judge clients by running “pc2judge.bat” and login ( for judge1 ) using the name “judge1” and password “judge1” and hence for other judges.
Judge: Judge receives all the source codes submitted by the teams and has to judge them right or wrong.
Start all PC2 Team client running “pc2team.bat” and login ( for team1 ) using the name “team1” and password “team1” and hence for other teams.
Team: The teams can send their source code by browsing it, selecting the problem and selecting the language.
Team: Teams get prompted whenever a decision is made about their source code and the scoreboard automatically updates as a team succesfully submits a problem.

So, here is the minimal use of PC2 software. For running a multisite contest or automated compilation of source code please refer the its documentation.
Happy coding..!!

* * * * *

Algothematics.. All the Mathematics you missed

2010-03-15T00:04:00.000-07:00

Algothematics is a new event being introduced in Zealicon '10 (annual TechFest of JSS Academy of Technical Education, Noida). The event will be conducted online. All programmers across the world are, hence, invited.

The event comprises of 15 levels. Each level has an ad-hoc mathematical problem which can either be solved manually (using pen and paper) or by conceiving certain algorithm. The submission requires only the answer to the question. Submission of source-code is not required.

Other tools can also be used for solving the problems. Spreadsheet, PARI-GP, MATLAB are among them. Besides all these we always have GOOGLE with us... :)

Besides all this, Zealicon forum will contain an "Algothematics" thread under "online events" where all sorts of problems and their hints will be discussed. No questions extraneous to the event will be entertained.
LeaderBoard will be available at the home page itself, so that you can constantly check your position among others.

Please do not ruin the basic purpose of event by any hacking stuff. Those not conforming to the rules and regulations will be banned without prior information. Decision of Algothematics Team will be the last.

First two teams reaching the final level will be adjudged victorious..

So pull up your socks, hone your programming skills.. Algothematics is about to begin..!!! (17th March, 00:00)

* * * * *

cmath v/s math.h

2010-02-19T04:20:00.000-08:00

Here's a problem with pow() function in cmath and math.h:

With gcc set up, math.h just contains the the usual C function pow(double, double) - so all the functions work because with pow(int, int) both ints get promoted to double by compiler and all is OK.
cmath in more than a wrapper for math.h. First it includes math.h and then undefines a whole lot of stuff that math.h defined, and substitutes the c++ versions.
This includes the pow function declaration.
As the c++ overloaded functions (same as any other c++ compiler), you will get the ambiguity problem - when using pow(int, int).

P.S. - The ambiguity occurs with pow(int, int) because integers can be promoted to floats or doubles, which means that pow(int, int) can fit the so overloaded c++ pow function - so the compiler gets confused.

* * * * *

How to make a good Website..

2010-02-11T08:55:00.000-08:00

Answering the question "how" to make a Website is an easy task for many of us but the question which really puzzles us is "what" makes a good Website. We all visit many sites daily while surfing the net but there are a very few of them which leave an impression in our mind. Many sites are technically fine but fail on aesthetic grounds.

What makes a good WEBSITE:

Content:
The most important element of a website is its content. An interesting, informative and dynamic (updated frequently) content makes people visit the site again and again. The flashy colours or animated images look good at first but they never compell us to visit a site again and again. Only good content can do that.
Web is primarily a visual medium and its quite cumbersome to read text screen after screen. Try to keep the content to the point. Never elaborate.

Visuals:
Try not to Bold and Italicise the text too much, it gives an ameturish touch to your website. Sometimes underlined text get users confused with a hyperlink. Try avoiding it too. Make sure that the font size is even throughout. Do not wildly vary the size unless required.
Leave lots of blank spaces. Text on computer screens is hard to read, so don't cram up your text. Start lots of new paragraphs, and leave plenty of spaces between words and objects. Headings or horizontal rules are a good way to do this.
Do not use flashy colours as explained above. Try to select a good and readable combination of colour scheme. White text on black background may look classy but its difficult to read specially when text size is small.

Technicalities:
There are many things that make your web page look a bit different as what you expected:

Different browsers may show your web page differently. Try using a javascript available on net that kills this variation.
Sometimes web page view gets distorted on lower resolutions. Give a message on your website as "Website is best viewed in 1024X768" or anything like that.
The person viewing the web page may have certain settings different from yours.

Some tips:

To prevent your sites to look weird on text-only browsers you can add 'ALT' tags to ALL your images. If there is no alternative text that makes sense, use alt="" - this will help text-only browsers more than you will believe.
You can add a site search to your site. This will allow users to search your entire site easily and quickly.
Make sure that wherever your visitor is in your site, they can get to any other area. Also make sure they know where they are!!

As earlier said making a website is not a difficult task, it is designing and making people visit it again and again that makes it difficult. You need to make your website pretty different from all the other billions, floating on the internet.

* * * * *

My way of writing a Quine

2010-02-04T02:41:00.000-08:00

Here I m presenting a Quine written by me few days before. A Quine is a program that prints its own source code. In my source code user has an option of printing the source code n number of times.

Here is the code written in c:

#include < stdio.h >
int main()
{
 int n;
 char c;
 FILE *f;
 f=fopen(__FILE__,"r");
 scanf("%d",&n);
 while(n--)
 {
  while((c=getc(f))!=EOF)
  putchar(c);
  fseek(f,0,0);
 }
 return 0;
}

Here is the code written in c++:

#include <fstream>
#include<iostream>
#include <cstdio>
using namespace std;
int main()
{
    int n;
    string a;
    cin>>n;
    while(n--)
    {
        ifstream fin(__FILE__);
        while(!fin.eof())
        {
             getline(fin,a,'\n');
             cout<<a><<"\n";           
                }      
           }      
     return 0;
 }

* * * * *

Configuring IIS Web Server

2010-01-27T07:16:00.000-08:00

The ASP .NET pages can also be hosted through apache but it requires a hell lot of configurations and changes. An alternate version is IIS web server that comes already installed with your windows OS.
Vista OS has an already installed IIS web sever. One just needs to turn the feature on, through control panel. In XP OS you need to install it through XP CD.

Never try to configure IIS on Vista Basic you will land no where in the end. The OS is not provided with the complete package. ISAPI filters cannot be installed correctly on Vista Basic. Certain features of ISAPI filters need to be checked while hosting the website. The safest option is to configure the server on XP.

The steps for configuring it are:

Turn the IIS feature on through control panel.
Check installation by typing 'http://localhost:80/' in your browser. IIS page will appear.
Goto run and type inetmgr. This makes a window pop up. Window is that of IIS Manager.
The next step would be to create a virtual directory for an existing physical directory. For this you need to expand the Web Sites item in the IIS tree, right-click the Default WebSite item and choose New -> Virtual Directory from the menu.
Then comes the virtual directory creation wizard. The first step in the wizard is to choose an alias. The alias is the name, a user will use, in his URL to access the files in this virtual directory.
The next step in the wizard is to provide an existing physical directory to which the virtual directory will point to. So, this physical directory will be exposed as a virtual directory through its alias.
The final step in this wizard is to choose your permissions for the virtual directory. Usually, to host an ASP.NET application, read and execute permissions are enough. Of course, in order to fulfill your needs you can choose other permissions too.

* * * * *

My submissions to SPOJ problem- TEST

2010-01-21T07:02:00.000-08:00

My interest lies in programming languages. Actually, I have a bad habit of trying every type of weird thing and this time I came up with the idea of trying a simple problem in every possible programming language I know. I tried to solve the first problem of SPOJ named Test. Here are my codes:

C:

#include < stdio.h >

int main()
{
int n;
scanf("%d",&n);
while (n!= 42) {
printf(""%d", n);
scanf("%d",&n);
}
return 0;
}

C++:

#include < iostream >
using namespace std;

int main()
{
int n;
cin>>n;
while (n!= 42) {
cout<>n;
}
return 0;
}

C#:

using System;
public class Test
{
public static void Main()
{
int n;
while ((n = int.Parse(Console.ReadLine()))!=42)
Console.WriteLine(n);
}
}

Java:

public class Main
{
public static void main (String[] args) throws java.lang.Exception
{
java.io.BufferedReader r = new java.io.BufferedReader (new java.io.InputStreamReader (System.in));
String s;
while (!(s=r.readLine()).startsWith("42"))
System.out.println(s);
}
}

Python:

n = input()
while n != 42:
print n
n = input()

PHP:

< ? php while(1) { fscanf(STDIN,"%d",$n); if ($n == 42) break; print "$n\n"; } ? >

BrainF*ck:

>+[>>,----------[>,----------]+++++[<-------->-]<[>>-<]>+[
-<+++++++[<------>-]<[>>-<]>+[
-<<[>>-<]>+[<<->>->]>
]<+++++++[<++++++>-]>>
]<++++++++[<+++++>-]< [<]<[>>[++++++++++.>]++++++++++.[[-]<]]<]

* * * * *

Introduction to various programming languages

2010-01-15T01:16:00.000-08:00

Hey folks, I recently researched about various Programming Languages. Here I m going to discuss certain attributes of each language.

Basic
Year Introduced: 1964
Paradigm: Imperative, Procedural
Standardization: Yes, ANSI, ISO
Type Strength: Varies by dialect
Intended Use: Application, Education

C
Year Introduced: 1972
Paradigm: Imperative
Standardization: Yes, ANSI C89, ISO C90/C99
Type Strength: Weak
Intended Use: System

C++
Year Introduced: 1979
Paradigm: Imperative, Procedural, Object-oriented, Generic
Standardization: Yes, ISO
Type Strength: Strong
Intended Use: Application, System

C#
Year Introduced: 2000
Paradigm: Imperative, Object-oriented, Functional, Generic, Reflective
Standardization: Yes, ECMA, ISO
Type Strength: Strong
Intended Use: Application, Web

Haskell
Year Introduced: 1990
Paradigm: Functional, Generic, Lazy evaluation
Standardization: Yes, Haskell 98
Type Strength: Strong
Intended Use: Application

Java
Year Introduced: 1995
Paradigm: Imperative, Object-oriented, Generic, Reflective
Standardization: No
Type Strength: Strong
Intended Use: Application, Web

Perl
Year Introduced: 1987
Paradigm: Imperative, Procedural, Reflective, Functional, Object-oriented, Generic
Standardization: No
Type Strength: Weak
Intended Use: Application, Text processing, Scripting, Web

PHP
Year Introduced: 1995
Paradigm: Imperative, Procedural, Object-oriented, Reflective
Standardization: No
Type Strength: Weak
Intended Use: Web, Server-side

Python
Year Introduced: 1989
Paradigm: Imperative, Object-oriented, Functional, Aspect-oriented, Reflective
Standardization: No
Type Strength: Strong
Intended Use: Application, Scripting, Web

Scala
Year Introduced: 2003
Paradigm: Object-oriented, Functional, Generic, Lazy evaluation, Imperative
Standardization: No
Type Strength: Strong
Intended Use: Application, distributed computing

* * * * *

Why, what n how to Blog..

2010-01-06T01:54:00.000-08:00

Why to Blog?
My Blogging habit commenced from January 2009 and I still love it a lot..!! I have a second blog running parallely. Here is its URL.
Blog is something that displays your thoughts to the outer world. Whatever is in your mind, you can deploy that on your blog, as its all yours. Many use blog for helping others, many use it for storing memoirs, many use them for technical discussions and many for fun and money. If you are addicted to writing.. blogging is your domain for sure.

What to Blog?
Its Important to know where your interest spans. A personal blog may contain all the happenings in your life and pictures to display them. A technical blog may contain certain useful information which you found out recently or which is the latest trend. A news blog may contain all recent updates about world, movies, sports, music etc. The thing that matters is your interest.
The second most important aspect of blogging is the content of your posts. The content must be precise, interesting and informative. For attracting more traffic to your blog you need to get a nice title to your posts. These titles get Googled frequently and increase the page rank of your post.

How to Blog?
There are many sites that offer you space to make your own blog. Some famous ones are Blogger, Wordpress, Tumblr, Procetours. I chose Blogger just because I was not having any idea about the others at that time!! I dont want to shift my blog now because then I will have to compromise with my page rank. Certain pre-built tools and gadgets are provided to the bloggers free from these sites. Javascripts may be used to build own tools.
Now, here are some tips from my side that can help bloggers in monitoring their blog and see who visits them.

Google Analytics: Its Google again :).. The analytics gives you a huge amount of information about the visitors of the blog viz the page they visit, amount of time they spend, the area from where they belong, the site from where they refer, how often they visit, even the operating system they use and the browser too..!! :p Visit Google Analytics, register yourself and your blog and enjoy tracing back your visitors. It will ask to add certain Javascrpit onto your home page and some other operations which can easily be done.

Feedjit: FeedJit is a cool tool. It displays the visitor on your blog in a real time basis. The visitors' location will be displayed on the blog itself at whichever corner you wish to place the tool. On clicking the real time display, it shows every visitor location, the sites from where they referred your blog and the keyword they typed in if they Googled your blog and also to which page did they exit. Go for it.. its free.. at least for now..!! :p

Google Feedburner: Recently added to Google. It allows you to generate feeds and sends them to each of your blog's subscriber. RSS feeds or ATOM, anyone can be chosen to begin with.

If you are interested in money making and have a decent regular traffic, you can add Google Adsense onto your blog. Google provides you with some advertisements of other companies which when clicked by a visitor lets you make money. The advertisements are mostly related to the content of your blog.

All these may help you in forming and maintaining your blog. If you have more information.. comments are surely invited..!!
HAPPY BLOGGING..

* * * * *

Some more problems of SPOJ...

2009-12-15T23:46:00.000-08:00

I recently breached into the top 1200 ranks in the world, but sad news is, soon I'll be thrown out too. The points keep on decreasing on a regular basis. Never mind this works as an incentive to work on more and more problems. :)
So, m writing this post for some more problems of SPOJ. The problems I m going to discuss are of an average level.

BISHOPS: Its an easy problem, if we try verbally. The answer is (2*n-2) i.e. equal to the number of diagonals. But the difficulty lies in the range of the inputs. N<=10^100..!! OMG!!.. :).. Try strings..

MINCOUNT: Actually what I did.. I tried it out for certain test cases and found that the answer is.. (n*(n+1)/2)/3.. i.e. the total number of coins in the triangle divided by 3. But why its so.. its still unanswered for me.. kindly post the explanation if you get one..!! :)

HUBULLU: Same mincount type problem here too.. seeing the discussion in the forum I got some hints that who so ever plays first wins.. So, it became a very very easy question for me to crack but why it happens is yet not understood by me..

TRICOUNT: Its another mathematics problem.. try it for sometime with all yours geometrical anlysis and at one time you will definitely come out with a solution that is much like (t*(t+2)*(2*t+1))/8.. where t is the level of triangle. Try it now yourself..!!

SAMER08F: Another age old problem of how many squares are there in a given bunch of squares?? Answer lies in the sum all squared numbers till the number of squares in each side of the grid i.e. if N=8 then answer= (1*1) + (2*2) + ... + (8*8).

Seeing my last three posts of SPOJ I think now its easy for any newbie to get started. So, no more discussing algorithms of SPOJ problems from my side. Keep practicing and who knows one day you beat [Trichromatic] XilinX..!! :p

* * * * *

SPOJ: Some very easy problems

2009-11-21T06:37:00.000-08:00

Its been a month since I have started coding in SPOJ. There are over 5000 problems present there. Its really gets very tough when one tries to get some easy problems from that lot. So, I dedicate this post to beginners. Go for the below mentioned problems.

Some very easy classical problems:

TEST- This is the first problem I solved in SPOJ. I recommend the same for you. It gives a brief introduction of the whole environment. What you need to do is to accept and print the input by the user until you come across 42. The easiest problem at SPOJ and a confidence booster to begin with..!! ;)

ADDREV- Take two numbers as input. Reverse both. Add the reversed number. Reverse again. Simple..!! The thing you need to keep in mind is that you have to provide the number of test cases first. While taking the inputs you can print the result too. You need not store them and print later.

FASHION- Quite big explanation of the problem (a bit interesting too ;) ). The only thing you need to keep in mind is that you have to sort the degree of hotness of men and women and then multiply and add them up. If you do not sort them, it will give a WA.

MIRRORED- Print "Mirrored pair" wherever you confront "bd" or "db" or "pq" or "qp", otherwise print "Ordinary pair". Don't forget to print "Ready" in the beginning. You do not have to take the test cases as input here. Just end the input when you confront two spaces. I got an AC at very first attempt..!! Hope the same for you.. :)

NSTEPS- Analize the graph properly. Whenever x and y co-ordinates are even the corresponding output is (x+y) for input (x=y) and (x=y-2). When they are odd the corresponding ouput is (x+y-1) for input (x=y) and (y=x-2). You can also do the problem with a different approach too. You can form a series for the numbers, and hence, generate the output.

OFORTUNE- Common.. don't get astonished by the enormous length of the question. Try tackling the problem. It just needs six inputs and a simple interest and compound interest formula implementation thats it.. Try it.. You will gain a hell lot of points..!!

Some very easy challenge problems:

SIZECON- The difficulty doesn't lie in the problem statement. The difficulty lies in the choice of programming language. I managed to do it in 96 characters. Best solution in c++ has 70 characters in it. Perl language wins with just 6 characters..!!

BFWRITE- I have already written a post about this problem. Try learning Brainf_ck language and solve this problem too. Here's the link to my post.

More easy problems are being searched. Kindly mention some in comments if you confront one.. Here's my SPOJ handle.. vaibhav_pandey.

* * * * *

Getting started with Project Euler

2009-11-14T22:58:00.000-08:00

Hello folks.. After getting started with SPOJ and TOPCODER, lets get started with another fine programming competition which is Project Euler.

The first question which originates is.. why Project Euler??

My answer.. why not?? If you are interested in programming.. make yourselves interested in mathematical shortcuts and logics for solving problems too. Project Euler is a site that provides you problems that bind you to explore some unexplored areas of mathematics. Now, lets get started..

Steps:

Get registered.
See the problems from problems tag. There are more than 260 problems at present.
Solving problems requires you either to build a source code that computes the asked value or to pick up pen and paper and start solving. My advice.. prefer the earlier one..!! :)

Your profile consists of the number of problems you have solved. Your ranking is based on levels. If you have successfully solved 25 questions you qualify to the level 1 and so on and so forth. On solving a problem its thread gets unlocked and you can check solutions of others in the languages they preferred. Thus, you can compare your code with others.

Your profile gets dissolved if no activity happens in 90 days of time. This happens if you are 0, 1 or 2 level programmer. Level 3 and level 4 programmers are granted immortality, thus, here lies the advantage of being superior.. 8)
So, get started with Project Euler and hone your programming skills..

To see my profile, first register to the site and then type the URL: http://projecteuler.net/index.php?section=profile&profile=vaibhav_pandey

* * * * *

My experience with BrainF_ck Programming Language

2009-11-05T09:34:00.000-08:00

Hi folks.. Last few days I worked a bit on BrainF_ck language. A nice language that may be used for encoding sort of stuff. What we code in it.. it might happen that we ourselves forget about it, such is the level of complexity of the language!!
The brilliant factor about the language is that it is just made of eight symbols in total..!! Surprised.. so was I..!! :D

Whole of the language depends on just an array. Every manipulation has to be done in the array using a memory pointer, which moves through the memory blocks of the array. Now, getting over to the practical implementation of the language. The eight symbols are:

> = increases memory pointer, or moves the pointer to the right 1 block.
< = decreases memory pointer, or moves the pointer to the left 1 block.
+ = increases value stored at the block pointed to by the memory pointer
- = decreases value stored at the block pointed to by the memory pointer
[ = like c while(currentBlockValue != 0) loop.
] = if block currently pointed to's value is not zero, jump back to [
, = like c getchar(). input 1 character.
. = like c putchar(). print 1 character to the console.
I made my first program for SPOJ challenge problem BFWRITE. Before going through the code I would give you the link of an online compiler for BrainF_ck language. I prefer BrainF interpreter. So now, here's my code:

++++++++++
[
>+++++++>++++++++++>+++<<<-
]
>+++++++++++++.
---.
-.
-----.
>>++.
<+++++.
++++++++++.
>.
<----------.
+++++.
----------.
+.
.
-.
>.
<---.
++++++++++++++++++++++.
------------------.
++++++++++++++.
----.
--.
--------.

Looks quite difficult to understand but I'll make it simpler for you.

First line assigns value 10 to a[0]
Second line begins a loop checking value of current block a[0].
Third line moves pointer ahead once(>) and assigns value 7 to a[1](++++++). The same line then again pushes pointer to a[2] and assigns value 10. 3 value is given to a[3]. The pointer returns back to a[0](<<<) and decrements the value to 9.
In the fourth line.. loop goes on until the value of a[0] exhausts.
Finally the values are.. a[0]=0, a[1]=70, a[2]=100, a[3]=30.
The sixth line decreases a[1] by 3 and makes its value equal to 67. '.' prints the value 'S', ASCII code of 67.
Likewise the further lines print the text:- 'P','O','J',' ','i','s',' ','i','n','d','e','e','d',' ','a','w','e','s','o','m','e'. Hence on our output comes as:- SPOJ is indeed awesome.

I further improved my code to 153 characters. Instead of making the array 70, 100, 30 in the beginning I made the array as 64, 32, 104, 112. Try it out yourself to optimize the code.

* * * * *

How to handle very large test cases in c++

2009-10-30T12:50:00.000-07:00

Most of us come across some c++ problems where we are asked to get some simple calculations done. For example: we can get a problem of subtracting 1 from a 100 digit number. Now, subtracting one is not a big problem for us but the problem is '100 digit number'.

None of the datatype has capacity to store such a large number. Stop thinking about unsigned long long.. even it cant..!! So, here's a short solution to this cute problemo..

We can take the input as a string and process each of its elements as in elementary mathematics i.e. if last digit is'nt 0 then reduce it by 1(dont forget it to convert to int and then back to string).. if last digit is zero then make it nine and move back to the adjacent digit following the same procedure. Simple :)

Here's the source code..

#include
using namespace std;
int main()
{
int i,t=40;
string z;
cin>>z;
i=z.size()-1;
do
{
if(z[i]!='0')
{
z[i]=int(z[i])-1;
break;
}
z[i--]=57;

}while(i>=0);

Then print the string a.

The only problem comes when we give input as 10, 100, 1000, 10000 ... the answer comes out as 09, 099, 0999, 09999... instead of normal numbers such as.. 9, 99, 999, 9999... I have resolved this problem for myself.. I'll not upload the source.. try it out yourself..!! ;)

* * * * *

Getting started with TopCoder..

2009-10-18T00:53:00.000-07:00

After successfully coding the first time in Topcoder, I really feel greatful in sharing my experience with all. Simply, it was great. Got to learn a lot of new things. I have started it too late but being in UPTU and that too in a college where seniors are not that into coding, it was still very early.. ;)

So, m writing this post to acquaint my mates with the TopCoder Competitions. What I m goin to discuss is all about the algorithm competitions.
Top Coder is a programming arena where you are given a set of problems and you have to solve them (in your preferred language) in a given amount of time. There are some simple steps to follow before starting with the coding competition:

Goto Topcoder site and get yourself registered.
Now when you are registered, download the Topcoder arena. You will need Java to be installed in your system for making the applet run.
Get yourself an editor(I use KawigiEdit). The editor helps in generating the code required for the competition. If you need help to install it.. read this.
Start the contest application and start navigating. There are practice rooms where you can practice the earlier SRM's(single round matches).

SRM are the single round matches which are organized twice every month. You are given three problems to solve. What you need to do is to generate the code using KawigiEdit and simply put your logic in the function provided.
The important point about TopCoder is that you don't use the main() method in your code. All your logic is dumped inside a function and you have to return your answer instead of printing it.
The several phases of the competition are:

Coding Phase: During this phase you are given 75mins of time to solve as many problems as you can. What you need to do is to write your code, compile it and after rigourous testing on test cases provided and some of your own test cases, "submit" it.
Intermission: 5mins intermission.. I hear a song usually.. :)
Challenge Phase: During this phase in 20mins time any of the room members can see your code or you can see theirs. If anyone finds anything wrong with anyone's code, he can simply challenge it. If he succeeds the submitted problem will be discarded and points will fall back to 0.00
System Testing Phase: After the challenge phase comes System Testing Phase. This takes a fare bit of time. After near about 20mins you can goto tools and room summary for checking whether your code passed the System Testing or not.

After about 2 hrs of play the result is out..!! If you see your name coloured (Green,Blue,Yellow,Red), feel like a champ. If you are Grey, you need to practice more and more. The colors listed above are in hierarchical order.. i mean Red is the highest pointer(2200+) whereas grey is the lowest(001-899).

Being associated with IEEE, TopCoder is a good platform for being recruited. Moreover, it hons your programming skills, giving your career a boost.

You can watch your entire TopCoder profile by just entering your username in the handle.
I m listing some of the TopCoder handles that will inspire you a lot..
Some foreigners:
ACRUSH
petr

Some Indians:
konqueror
innocentboy
vijay03
shalinmangar (from JSS.. a thing to feel proud of..)

Here's my handle.. its not that good.. I'll improve it further.. m sure..
vaibhavpandey

* * * * *

SIGSEGV error in c++ programs

2009-10-14T03:52:00.000-07:00

While solving a question TOANDFRO in spoj I was introduced to the SIGSEGV (segmentation fault) error. The very first thing, as I often do, I googled the error. The forums I visited and info I got simply did'nt tell me what exactly went wrong with my code. So, after a "deep-deep" analysis I m here to provide my readers with the solution to such an error.

There are various causes of segmentation faults, but fundamentally, you are accessing memory incorrectly. This could be caused by dereferencing a null pointer, or by trying to modify read only memory, or by using a pointer to somewhere that is not mapped into the memory space of your process.
A segfault basically means you did something bad with pointers. This is probably a segfault:

char *c = NULL;
...
*c; // dereferencing a NULL pointer

Or this:

char *c = "Hello";
...
c[10] = 'z'; // out of bounds, or in this case, writing into read-only memory

Or maybe this:

char *c = new char[10];
...
delete [] c;
...
c[2] = 'z'; // accessing freed memory

* * * * *

Getting started with SPOJ (Sphere Online Judge)

2009-10-03T11:44:00.000-07:00

After successfully getting involved in SPOJ I think I must give a little idea of it to others too. SPOJ is an online coding website for practicing ACM-ICPC style problems.
You need to join this website if you are interested in coding and have a thirst to solve new problems otherwise you can sit back and relax hearing your music stuff.. :p

To start with you can register for SPOJ here.
After getting registered you can see number of problems. Right now there are around 4K+ problems at SPOJ. For submitting a problem in whichever language you desire you can click submit and submit your file or directly the source code. One of the best things about online judges is their instant feedback. You dont have to wait for your program to get judged! The judge results are:

Accepted – The output from your program perfectly matched the required output. This problem is then added to your list of accepted problems.
Time Limit Exceeded – It means your program took too long to execute. Try optimizing your program and check for accidental infinite loops.
Wrong Answer – Your program ran on time, but it did not produce the required output.
Compile Error -Your program had some syntax error. For these errors, click on the text “Compile Error” in the judge result. It`ll take you a page which will list the compile errors and their line numbers in your program. The compilation error can also be sent to you as mail.
Runtime Error – This is usually accompanied by a code like SIGSEV. It can happen due to a lot of reasons, but the two most common are using too much memory ( you can use around 6000*6000*4 bytes of memory ) and not remembering to use int main() and return 0 in your programs. (NZEC error).

Your ranking in SPOJ arena is dynamic. More the number of users who solve the problem you'v solved lesser will be points gained. The points you gain in SPOJ come with the formula:

points= 80/(40+users successfully solved the problem)

So, more the difficult question you solve more points you get and higher is your rank. Even your institute gets ranked on your points. Check your institute's rank here.

Here is my SPOJ handle.. vaibhav_pandey

Start coding now!!!

* * * * *

SCALA programming language

2009-09-29T10:50:00.000-07:00

While coding in SPOJ. I came across a new programming language named SCALA. I searched a hell lot of things about the language.

Scala goes out of it's way to make sure you don't need to program in a functional style. This is the main criticism of Scala from functional folks, as a matter of fact: some do not consider a language functional unless it forces the programmer to write in functional style.
Scala already introduces some nice features, comparable to some stuff that's present in C++ but not Java, though they work in different fashion. In that respect, once you realize what such features are for and relate them to C++ stuff, you'll be much ahead of Java programmers, as you'll already know what to do with them.

Some of the downsides of Scala are not related at all to the relative youth of the language. After all, Scala, has about 5 years of age, and Java was very different 5 years into its own lifespan.
In particular, because Scala does not have the backing of an enterprise which considers it a strategic priority, so the support resources for it are rather lacking. For example:

* Lack of extensive tutorials
* Inferior quality of the documentation
* Non-existing localization of documentation
* Native libraries (Scala uses Java or .Net libraries as base for their own)

* * * * *

Optimization

2009-09-20T13:12:00.000-07:00

During coding, what we need to keep in our minds is optimize the code. The direct code which hits our brain at the first instance is generally not that optimized. If given a large test case to examine the code, it fails to complete the execution in time. I came to know about this while playing online a coding event in which besides code to be right one's code should run in an asked period of time. For this we need to optimize our code a great extent.
I was asked to print all the prime numbers between given two numbers. The first code that comes to our mind is to run a loop and find all the prime numbers by dividing each number with every other number. Mind you, this takes a hell lot of time. One can optimize the code easily by discluding the numbers that get divided by 2,3,5. This takes away numbers out from the loop that prevent us from checking them. The time limit set hence becomes a little reachable.
The second thing is logic. One can even look at the problem at different angle. You can yourself Google and find that there are many other good methods of finding a prime number. One method needs the loop to run only for (n)^(1/2) times. This also reduces the time a great deal.

CODE IT.. OPTIMIZE IT!!

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Back up your Gmail account

2009-09-11T03:52:00.000-07:00

Gmail doesn't have to go down globally for our email access to be cut off—our internet could go down, or our account could even be disabled. Whatever the case, it's a good idea to have a backup plan just in case the worst should happen.

They've got us covered with a number of methods for backing up our Gmail, starting with the really obvious solution of just using Thunderbird to back up our email with POP access, but we can backup our email with Fetchmail on Windows, Getmail on Linux, the standalone Gmail Backup tool, or even use Google Groups to backup your Gmail account.

So, don't think much.. just get urself backed up!!

* * * * *

Google Code Jam 2009

2009-09-03T18:29:00.000-07:00

This was the first time I registered for Google Code Jam. Researching about this great event I came to know that it gives way to free use of languages. Google allows its participants to code in any language they wish to. Starting from c, c++, java, batch files to php, perl, brainf*ck and all.

It was the qualification round in which I scratched my 'hairless' head throughout the day. The round consisted of three questions. One had to submit an output file of solution of test cases. Each question consisted of two test cases small and large. 4 minutes of time was given to a participant to upload his source code file and the output file in small test cases. Time was increased to 8 mins in case of large test cases. It was necessary to solve at least one small test case and one large test case of any question to qualify for next round. I was able to solve a small one.. :)

The question I solved was called "Alien Language". One can easily 'google' the whole question. I m giving the source code which I submitted :

using namespace std;
int change(string strConvert)
{
int intReturn;
intReturn = atoi(strConvert.c_str());
return(intReturn);
}

void main()
{
ifstream myfile("g1.txt");
ofstream opens("g2.txt");
string line;
int cases=0;
char words[800][800],letters[800][800],answers[800][800];
int L,D,N,r=0,c=0,f=0,m;
getline(myfile,line,' ');
L=change(line);
getline(myfile,line,' ');
D=change(line);
getline(myfile,line,'\n');
N=change(line);
for(long int i=0;i++)
{
getline(myfile,line,'\n');
for(int j=0;j++)
{
words[i][j]=line[j];
}
words[i][L]='\0';
}
for(int q=0;q++)
{
cases=0;
r=0;
getline(myfile,line,'\n');
f=0;
m=line.size();
while(f!=m)
{
if(line[f]=='(')
{
while(line[f]!=')')
{
f++;
if(line[f]!=')')
{
letters[r][c]=line[f];
c++;
}
}
letters[r][c]=NULL;
f++;
r++;
c=0;
}
else
{
letters[r][c++]=line[f];
letters[r][c]=NULL;
r++;
c=0;
f++;
}
}
for(long int s=0;s++)
{
f=0;
for(long int k=0;k+)
{
for(long int a=0;a++)
{
if(words[s][k]==letters[k][a])
{
f++;
break;
}
}
}
if(f==L)
cases++;
}
opens<<"Case #"<<<": "<<<"\n";

}
getch();

}

Explanation of code:

What I did in the program is that I took each word of language into a double dimension array called 'words'. Each test case was then bifercated into letters in another double dimension array called 'letters'. The first letter in words was then regularly checked in the different letters of each test case. The moment it matched the loop got broken with an increment of a flag called 'f'. The moment flag became equal to length of word it was sure that the given combination exists, hence, the case variable gets incremented which is ultimately our answer and gets written in the output file.

The only problem that came with this solution was during the execution of large test case. It would have been easily implemented through vectors but lack of time compelled me to quit upon it. Actually, due to continuous memory allocation sometimes due to large datasets, the values get written on read only part of memory which generates errors.

So, I settled with a 10 point mark.. BTW my first experience with Google Code Jam was awesome..!!

* * * * *

Installing apache on windows

2009-08-31T03:23:00.000-07:00

Instalation:

First thing you need is to download the webserver. Now for windows users you will have to go for the .exe . The apache website is www.apache.org. You have to head to the apache binaries sections for Win32. I believe it is at http://www.apache.org/dist/httpd/binaries/win32/
There you will be able to download a version of apache.

Now before you download it you have to make a folder. This folder is one which serves as the root directory. Now if you don't want to do this it's ok. You can use the default path if you want. But usually this helps in setting up other things like php, and MySQL. Most people create a folder in the C:\ directory called WWW or somthin. You can name it whatever you want.

Ok so you have downloaded the Apache Web Server and ready to go with the setup. The version I have downloaded was apache_2.0.36-win32-x86-no_ssl.msi. This was a newer version and supposedly supposed to be more secure.

The first screen you get when your in the setup is the welcome screen, we don't care much about that.

The next screen is the terms and service. And yes you are going to agree to the terms.

The next screen is some documentation. I never really read it but if you want go ahead and do it.

Now we see a screen that says enter a network domain. Erase what's in there and type localhost.

Now the next box says Servername, erace what is ever in the box and put in localhost.

The next is Administrators e-mail address. Go ahead and fill that in. But make sure to change it.

Pick radio button that best suites your needs.

Now that we got that all filled out. Hit Next and you'll go to a screen that asks you which type of install you want to do. Then hit next.

If you wanted to server out of your one special folder. Change the file location where you were going to install apache. Or just leave it as the default path. Click install and it should be on it's way. Once it's done installing hit the finish button.

The test:
First were gonna check to see if Apache installed correctly.
This is how we do it. Open up Internet Explorer and type in " http://localhost" . If everything went smooth then you should be seeing a message that looks like this" Seeing this instead of the website you expected?" Yippee!!!
Apache is working.

* * * * *

DB2 Certification

2009-08-13T01:53:00.000-07:00

A few days training and a stressfull test. All gave me an IBM DB2 associate certificate. What a relief at last!!I would like to share my experiences with the software. BTW m still learning a hell lot of things in it.
DB2 is a database handling software that helps in maintaining large databases. I learned its express-c edition which is available in market free of cost but the most eye catching was the everyplace edition that works on mobile phones. I did'nt get the chance to work on it but soon I will.The installation process though was simple yet hectic. Lots of errors.Command center, configuration assistant, task center, journals, health center, sql assist were all easy to understand. It was very much comfortable to build the sql statements on sql assist with a GUI interface. Express-c edition comes with a pure XML add-on feature. The XML datatype helps in including the XML files in a database. XML files have user defined tags which is where they differ from HTML files where the tags are pre-defined. XML files mainly find their use in transportation and storage of data.Working on sql queries was not new but that on xqueries was a new experience.
Three cheers for IBM for making us, the "UPTU's ruined geniuses", understand such a software. DB2 9.7 "VIPER2" is what I m looking ahead for.

* * * * *

The problem of fu#king "Back" button..

2009-08-07T00:28:00.000-07:00

Sorry for my indecent title but I was so irritated by this "back" button that I cud'nt stop myself.
After a user logs out himself from a web page and presses the "back" button of his browser he again gets himself logged in. The problem really makes you scratch your head sometimes. I did the same and came out with a cool solution.

The page in which you are asking user to log out just write the two statements on page load():

Response.CacheControl = "no-cache";
Response.Cache.AppendCacheExtension("no-store");

The two statements help in controlling the cache and preventing it to save the previous session.

Also make a session variable for login of a user. Make the session variable "true" whenever a user logs in and "false" when he logs out. Check on page load() of logout page, if session variable holds "false" value, direct the page to login page. Now if the user clicks back button he'll still remain in the login page or the page you wish to direct him.
My codes:

protected void Page_Load(object sender, EventArgs e)
{
Response.CacheControl = "no-cache";
Response.Cache.AppendCacheExtension("no-store");
if (Session["log"] != "true")
{
Response.Redirect("expired.aspx");
}
}

* * * * *

Cool query 'bout pointers

2009-08-06T21:51:00.000-07:00

While studying 'bout pointers I came about a cool phenomenon. Plzz don't laugh if its a but obvious thing for you. You might be a better coder than me for sure. I figured it out after a number of trials so I can't stop myself sharing it with everyone.

My question is.. Whats the difference between two statements..

int a=1;
int *p;
*p=a;//statement 1

AND

int a=1;
int *p;
p=&a;//statement 2

I played with number of printf's to come out with a simple answer. I again warn you if its a but obvious thing plzz do ignore it but it was a beautiful discovery for me though.

p=&a : in this statement, as we all know, the address of variable 'a' gets stored in pointer p and we say that pointer p points towards the variable a.

*p=a : (value of p is equal to a) in this statement, "as now I know", a new address is designated as value 1 and the pointer points to that address rather than pointing towards a. In simple words the address stored in p is not the address of a.

try two statements with..
printf("%u" "%u",p,&a);
In first you will find same address and different in the second.

* * * * *

~~`Coding Voding`~~

How to screw your telephonic interview in five simple ways !!

Algothematics.. back again !!

Getting started with USACO

an ACM experience

My Stackoverflow Badge

My Project Euler Badge

Getting started with Linux File System

My Android Applications

Some useful links for building Android Apps

Getting started on Android Application Development

Google Code Jam - 2010

Getting started with Programming Contest Control (PC2)

Algothematics.. All the Mathematics you missed

cmath v/s math.h

How to make a good Website..

My way of writing a Quine

Configuring IIS Web Server

My submissions to SPOJ problem- TEST

Introduction to various programming languages

Why, what n how to Blog..

Some more problems of SPOJ...

SPOJ: Some very easy problems

Getting started with Project Euler

My experience with BrainF_ck Programming Language

How to handle very large test cases in c++

Getting started with TopCoder..

SIGSEGV error in c++ programs

Getting started with SPOJ (Sphere Online Judge)

SCALA programming language

Optimization

Back up your Gmail account

Google Code Jam 2009

Installing apache on windows

DB2 Certification

The problem of fu#king "Back" button..

Cool query 'bout pointers

`Coding Voding`