Connect to Oracle database through Unix

Due to my professional requirements nowadays I use Oracle most of the time and sometimes I need to use Oracle through Linux environment. Today I am going to discuss the basics of connecting to Oracle database through Linux. For this purpose Oracle provided us a pretty cool utility with a basic command line interface. Yes, SQL*Plus is the utility I am talking about.

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Many times I have availed the Cab facility of my office whenever I got late for project work. But yesterday I got a new idea from some guys traveling with me in the same cab. In my office when I am availing cab service, its cost is going to be added on your project cost.

Introduction to Quantum Cryptography

Imagine you want to send some message to your friend and you don't want others to peek on your message. So you lock your message in a box using a key and send the box to your friend and your friend also have a key to unlock the box so he can easily unlock  the box and read the message. In general this is the technique used by any cryptographic algorithm. Locking up the message in  the box is called Encryption and Unlocking is called Decryption. Before message being sent to the receiver the data is encrypted using an encryption algorithm and a secret key. On the receiver side the encrypted data is decrypted using the reverse encryption algorithm. Classical cryptographic algorithms mostly rely on mathematical approaches to secure key transmission. The security  they offer is based upon unproven assumptions and depends on the technology available to an eavesdropper. But rapidly growing parallel technology and Quantum technology may be a threat to these classical cryptography in near future. One of the solutions of these threats is Quantum Cryptography. Now what is Quantum Cryptography? Quantum cryptography is a complex topic because it brings in to play something most people find hard to understand -- quantum mechanics. Now lets focus on some basic quantum physics that we must know to understand this article.

Searching an element in a row and column wise sorted matrix

First let me state the problem we will discuss in this post:  You are given a 2-D array of  nXn size with all the elements sorted in descending order row and column wise. You need to find a particular element in that array.
There may be lots of ways to solve this problem. I will discuss three ways to solve this problem using a
(i)linear search,
(ii)binary search,
(iii) binary search graph [ I know its bit confusing. Don't  go on the name ]

Use Indent to indent your C-code

I myself not very much expert in writing indented code and code without indentation looks just horrible. Of course you will not have same feelings if you are using an IDE with auto indentation facility and of course if you know how to write indented code. For this purpose I found Indent command very useful in linux. One thing you should remember that this command is only for C code.
Actually not me, one of my friend Arjun Pakrashi informed me about this command.

Iterative Quick sort

I am not going to state basic Quick sort algorithm or its implementation. We all know about these stuffs. Today I am going to focus on Iterative Quick sort implementation in C. We know that Quick sort is recursive in nature. So we need a stack data structure. For that purpose we may use recursive function or use an external stack data structure to simulate recursive functions.  Throughout the post I am going to use the leftmost element as the pivot element and we are only concerned about array implementation. 

Simple Power Set Generator

Currently I was trying to code some algorithm that one of my friend told me to do. In that algorithm I needed the code of a power-set generator. I first tried to code in my own way but it proved to be not so much simple. Then I found another simple logic to generate power-set. Logic is simple if you want the power-set of a set with n number of elements then just generate all the combination of n boolean variables.