DES Algorithm

 DES Algorithm

Complete playlist on Network Security

EJB 2.0 in details

1. Introduction to EJB 2.0
   
2. EJB APIs
   
3. EJB Roles
   
4. Transaction Management 
5. Implementing a basic EJBObject
   
6. Implementing a session bean
   
7. Implementing Entity beans
   

Implementing a basic EJBObject

 Implementing a basic  EJBObject

How do free Android Apps makes money

 This is how-to-make-money-from-free-apps.

Advanced JDBC

 Advanced JDBC concepts video series

What is Transactions in JDBC/EJB/Hibernate

 Transaction is based on the concept of ALL OR NONE

A Transaction must fulfill ACID properties.

Features of an Enterprise Application

 What's an enterprise application means and what are its characterstics

How are enterprise built and what are its basic components

Global variables in Python

 https://www.programiz.com/python-programming/global-keyword

Recursive problems: Example solutions

Problem 1:

'n' number of people are standing in a queue. People standing on even positions are selected. Of the selected people a queue is formed and again out of these only people on even position are selected. This continues until we are left with one person. Find out the position of that person in the original queue.

Solution:

#Python code

#declare a Global variable to store the last base case value of the recursion in it.

h = []

# The recursive function definition

def rec(l):

    global h

    m = []

    #see the list after each recursive call

    print(l)

    #see the size of the new list after each recursive call

    print(len(l))

    

    #base case

    if len(l) == 1:

        h = l

         

        

    if len(l)>1:

        #Getting the even indexed elements of the list

        for i in range(0,len(l)):

            if (i+1) %2 == 0:

                m = m + [l [i]]

# The above three lines can be replaced by following single line

# m = l[1::2] , this puts all the even indexed elements of list l in m. This also significantly improve #performance. Similarly, we can get odd indexed element with m = l[::2]

        rec(m)

    

    return h

# end of the recursive function

    

n=19

k = list(range(1,n+1))

#Call the recursive function

a = rec(k)

#Convert the only element in the list returned by the recursive function into a string

s = str(a[0])

print("Answer is " + s)

-------------------------------------------------------------------------

Output:

Problem 2

Print a sequence of numbers starting with a positive number N, recursively, such that  A[i+1] = A[i] - 5, as long as  A[i]>0. Once A[i] becomes negative, then  A[i+1]=A[i] + 5,  repeat it until A[i]=N.

Solution:

#Python code

def rec(n):

    print(n,end=" " )

    if n>0:

        n = n - 5

        rec(n)

        n = n + 5

        print(n,end=" ")

# end of recursive function definition

  

n = int(input("Enter the value of n :"))

rec(n)

--------------------------------------------------------------------------

Sample output:

Kaggle Learn

 Learn and practice how to build Machine Learning models for Data Science https://www.kaggle.com/learn/intro-to-machine-learning

Java EE architecture

 Java EE architecture video

Web server Vs Application server

 

Follwing vidoes explans the differences  between a web server and application server

1. https://www.youtube.com/watch?v=WkaLSZ888as
   
2. https://www.youtube.com/watch?v=ATObcDPLa40
   
3. https://www.youtube.com/watch?v=bgqtxlp7ftc
   

Python Essentials

 Great link to Python http://projectpython.net/chapter00/

Core concepts in Java Beans

 JavaBean concepts explained

How to create an installer for your desktop Java application

 You can build an installer (setup file) for your Java app like this creating-an-installer-for-java-desktop-application.

How to build Java executable

 To create executable Java file how-do-i-create-executable-java-program.

How to build Python executable

 Build Python executable from your .py file to run it on Windows without requiring to install Python on your computer py2exe

Cohen Sutherland Clipping Algorithm

 Explanation of clipping algorithm Cohen Sutherland Clipping Algorithms

Object Serialization in Java

 This video illustrates the concept of the 'Serializable Interface' and its use Why to implement Serializable interface

Accessing a Java Bean from a JSP file

 This video illustrates how to invoke a JavaBean class from inside a JSP file Accessing a Java Bean from JSP

The EJB Architecture

 The  EJB Architecture is based on the Java RMI Technology

Video series on EJB coding

Java Bean and EJB

 What is a Java bean Java Bean Video

The complete playlist on Advanced Java Advanced Java - Java as a Programming Suite

Online BSc in Computer Science from IIT Madras

https://www.onlinedegree.iitm.ac.in/academics.html

Program Execution (control flow) in a double recursive call

If a function calls itself twice recursively, its tracing tree (program execution/control flow) will be a binary tree

//Understanding double recursion part 1
#include<stdio.h>
//Global variable
int level = 0;
/*
split a list in two equal halves recursively,
and print the level of the binary tree for each node(function call) value pair.

This is the same function used in the DIVIDE & CONQUER technique (splitting
a list from mid recursive ) of  Merge Sort.
*/
void split(int low, int high)
{
    level++; //increment the level each step downwards journey of program execution
    int mid;
    //printf("low = %d High = %d Level = %d\n",low,high,level);
    printf("%d %d Level = %d\n",low,high,level);
    if(low<high)
    {
        mid = (low + high)/2;
        split(low,mid);               //split the left half recursively
        split(mid + 1,high);       //split the right half recursively
    }
    level--; //decrement level as retrace each step upwards the tree, of program execution.
}
int main(void)
{
    printf("For input 1 and 8\n"); // A list of 8 elements, index starting from 1
    split(1,8);
    printf("For input 1 and 16\n"); // A list of 16 elements, index starting from 1
    split(1,16);
    return 0;
}

Output:

/*
Understanding double recursion part 2
Making both the recursive calls in the
SAME line (return statement) also produces
the same result.
The only difference now is that you need to pass
the level as the third argument to the function.
*/
#include<stdio.h>
//Global variable
int level = 0;
/*
split a list in two equal halves recursively,
and print the level of the binary tree for each node(function call) value pair.
*/
int split(int low, int high, int height)
{
    height++; //increment the level each step down
    int mid;
    printf("%d %d Level = %d\n",low,high,height);
    //base condition
    if(low == high)
    {
        return 1;
    }
    if(low<high)
    {
        mid = (low + high)/2;
        return split(low,mid,height) + split(mid + 1,high,height);// The recursive calls in the SAME line
    }
    height--; //decrement level as retrace each step upward
}
int main(void)
{
    printf("For input 1 and 8\n");
    printf("%d \n",split(1,8,level));
    printf("For input 1 and 16\n");
    printf("%d \n",split(1,16,level));
    return 0;
}

Ouput: