
I think after reading lot of technical stuff in my blog you want something more exciting . 
So here are my life experiences when I stay alone in my home .
After a few paranormal activities in my home recently in past two years I have started believing in
spirits . May be its not over when some one leaves the world and there is life after death . The senior roaming
spirit didn't harm me but I could definitely feel its presence . So be good to others and be truthful to your self . 
If you also had same experiences in life then please share it with me . 

<style>
.iframe-container {
position: relative;
width: 100%;
padding-bottom: 56.25%; /* 16:9 ratio (9/16 = 0.5625) */
height: 0;
overflow: hidden;
border-radius: 8px;
}

.iframe-container iframe {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
border: 0;
}
</style>


## Paranormal activity 1
Paranormal activity when I was alone and when I was cooking for my self in kitchen I saw a heavy plate fell on its own behind me .

<div class="iframe-container">
<iframe width="560" height="315" src="https://www.youtube.com/embed/XwR8VHZdoKE?si=kOlAafvJo35ooyxb" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
</div>


## Paranormal activity 2
Paranormal activity when I was alone  in my home and when I was cooking for my self in kitchen I saw a plastic cover fell by itself  beside me .
<div class="iframe-container">
<iframe width="560" height="315" src="https://www.youtube.com/embed/gdoLshsHAjE?si=OeLsmyOEILRtw-cy" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
</div>


Paranormal activity


I hope you liked my post on [Bellman ford graph algorithm implementation in Java.](https://myblog-flame527.vercel.app/posts/graphs-using-linked-lists)
With slight changes to my existing code I have recently implemented the Unweighted Graph using linked lists algorithm in Java .
You can add additional weight field to the Edge class in case if you want to implement the minimum spanning tree algorithm using linked lists .

```java

/* copyright information 
   Author Name - Raj Gopal Bhallamudi
   Email - flame527@yahoo.com , rajgopal527@gmail.com
   Facebook - facebook.com/r5274
   Instagram - instagram.com/bhrajgopal
   */
   
   
import java.util.LinkedList;
import java.util.LinkedHashMap;
import java.util.Set;
import java.util.Iterator;
import java.util.Scanner;
import java.util.InputMismatchException;


	

class Edge {
	String edge;
}

class Graph {
	LinkedHashMap<String, LinkedList<Edge>> H = new LinkedHashMap<>();
	
}

public class Example {
	
	static int vertexCount=0;
	static int edgeCount=0;

	public static void main(String[] args) {
		
		Runtime runtime = Runtime.getRuntime();

      
        runtime.gc();
        long before = runtime.totalMemory() - runtime.freeMemory();

		Graph graphObject = null;
		bellmanFord(graphObject);
		
		runtime.gc();
        long after = runtime.totalMemory() - runtime.freeMemory();

        System.out.println("\n \n Total Memory used in bytes " + (after - before) );

	}

	static void bellmanFord(Graph graphObject) {
		Scanner scan = new Scanner(System.in);

		if (graphObject == null)
			graphObject = new Graph();

		int input = 0;
		
		

		do {
			System.out.println(
					"\n\n\n\n 1.create graph  2.print graph   3.insert vertex  4.insert edge\n 5.delete vertex   6.delete edge   7.search vertex   8.search edge \n 9.Delete graph 10.completed ");

			try {
			input = scan.nextInt();
			}
			catch (InputMismatchException e) {
	            scan.nextLine(); 
	        }
			
			switch (input) {

			case 1:
				if (graphObject.H.size() > 0)
					System.out.println("Graph already created");
				else
					creategraph(graphObject, scan);
				break;

			case 2:
				if (graphObject.H.size() > 0)
					display(graphObject);
				else
					System.out.println("Graph is empty");
				break;

			case 3:
				if (graphObject.H.size() > 0)
					insertvertex(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 4:
				if (graphObject.H.size() > 0)
					insertedge(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 5:
				if (graphObject.H.size() > 0)
					deletevertex(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 6:
				if (graphObject.H.size() > 0)
					deleteedge(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 7:
				if (graphObject.H.size() > 0)
					searchvertex(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 8:
				if (graphObject.H.size() > 0)
					searchedge(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 9:
				if (graphObject.H.size() > 0)
					del(graphObject);
				else
					System.out.println("Graph is empty");
				break;

			case 10:
				break;

			default:
				System.out.println("Invalid input received please try again");
				break;
			}
		} while (input != 10);
		 
		

	}

	static void display(Graph graphObject) {
		System.out.println("\n CREATED GRAPH IS \n");
		for (String vertex : graphObject.H.keySet()) {
			LinkedList<Edge> edges = graphObject.H.get(vertex);
			if (edges.size() > 0) {
				for (Edge edge : edges)
					System.out.print("(" + vertex + "," + edge.edge + ")"+ " ");
				System.out.println();
			} else {
				System.out.print("(" + vertex + ")");
				System.out.println();
			}	
		}
		System.out.println("\n\n Total number of vertices = "+vertexCount);
		System.out.println(" Total number of edges = "+edgeCount);
	}



	

	static void creategraph(Graph obj, Scanner scan) {
		String input, invalid = "END";
		LinkedList<String> vertex = new LinkedList<>();
		do {
			System.out.println("enter a vertex else type END");
			input = scan.next();
			if (!(input.equals(invalid)))
				if (!(vertex.contains(input))) {
					vertex.add(input);
					vertexCount++;
				} else {
					System.out.println("Duplicate vertex not allowed");
				}
		} while (!input.equals(invalid));

		for (int current = 0; current < vertex.size(); current++) {
			String currentVertex = vertex.get(current);
			LinkedList<Edge> edgeList=edgelistinsert(obj,currentVertex,vertex,scan);
			obj.H.put(currentVertex, edgeList);
		}
	}

	

	static void insertvertex(Graph obj, Scanner sc) {
		String currentVertex;
		System.out.println("Enter a vertex");
		currentVertex = sc.next();
		if (obj.H.containsKey(currentVertex))
			System.out.println("vertex already present");
		else {
			LinkedList<String> vertex = new LinkedList<>(obj.H.keySet());
			LinkedList<Edge> edgeList = edgelistinsert(obj,currentVertex,vertex,sc);
			obj.H.put(currentVertex , edgeList);
			vertexCount++;
		}

	}

	static void insertedge(Graph obj, Scanner sc) {
		String firstVertex, secondVertex;
		int duplicateFlag;
		System.out.println("Enter first end vertex");
		firstVertex = sc.next();
		if (obj.H.containsKey(firstVertex)) {
			System.out.println("Enter second end vertex");
			secondVertex = sc.next();
			if (obj.H.containsKey(secondVertex)) {
				LinkedList<Edge> edgeList = obj.H.get(firstVertex);
				duplicateFlag = search(obj, firstVertex, secondVertex);
				if (duplicateFlag == 1) {
					System.out.println("edge already present");
				} else {
						 Edge temp2 = new Edge();
						 temp2.edge = secondVertex;
						 edgeList.add(temp2);
						 insideinsert(obj,secondVertex,firstVertex);
						 edgeCount=edgeCount+2;
				     }
			} else {
				System.out.println("invalid second end vertex");
			}

		} else {
			System.out.println("invalid first end vertex");
		}
	}

	static void searchedge(Graph obj, Scanner sc) {
		String firstVertex, secondVertex;
		int flag = 0;
		System.out.println("Enter first end vertex");
		firstVertex = sc.next();
		if (obj.H.containsKey(firstVertex)) {
			System.out.println("Enter second end vertex");
			secondVertex = sc.next();
			if (obj.H.containsKey(secondVertex)) {
				flag = search(obj, firstVertex, secondVertex);
				if (flag == 1) {
					System.out.println("edge is present");
					return;
				}
			} else {
				System.out.println("Invalid second vertex");
				return;
			}
		} else {
			System.out.println("Invalid first vertex");
			return;
		}
		 if (flag == 0) {
			System.out.println("edge is not present");
		}
	}


	static void searchvertex(Graph obj, Scanner sc) {
		String vertex;
		System.out.println("Enter a vertex");
		vertex = sc.next();
		if (obj.H.containsKey(vertex)) {
			System.out.println("vertex present");
		} else {
			System.out.println("vertex not present");
		}

	}

	static void deletevertex(Graph obj, Scanner sc) {
		String vertex;
		System.out.println("Enter a vertex");
		vertex = sc.next();
		if (obj.H.containsKey(vertex)) {
			
			LinkedList<Edge> edge =obj.H.get(vertex);
			edgeCount = edgeCount - edge.size();
			
			
			Iterator<Edge> str = edge.iterator();
			while (str.hasNext()) {
				LinkedList<Edge> edgeList = obj.H.get(str.next().edge);
				iteratoredgedelete(edgeList,vertex);
				str.remove();
			}
			
			obj.H.remove(vertex);
			
			vertexCount--;

		} else {
			System.out.println("vertex not present");
		}
	}

	static void deleteedge(Graph obj, Scanner sc) {
		String firstVertex, secondVertex;
		System.out.println("Enter first end vertex");
		firstVertex = sc.next();
		if (obj.H.containsKey(firstVertex)) {
			System.out.println("Enter second end vertex");
			secondVertex = sc.next();
			if (obj.H.containsKey(secondVertex)) {

				int flag = search(obj, firstVertex, secondVertex);
				if (flag == 1) {
					LinkedList<Edge> edgeList = obj.H.get(firstVertex);
					iteratoredgedelete(edgeList,secondVertex);
					edgeList = obj.H.get(secondVertex);
					iteratoredgedelete(edgeList,firstVertex);
					
				} else {
					System.out.println("edge not present");
				}
			} else {
				System.out.println("invalid second vertex");
			}
		} else {
			System.out.println("invalid first vertex");
		}

	}

	static void del(Graph obj) {
		Set<String> vertices = obj.H.keySet();
		for (String vertex : vertices)
			obj.H.remove(vertex);
	}


	static int search(Graph obj, String firstVertex, String secondVertex) {
		int flag = 0;
		LinkedList<Edge> edgeList = obj.H.get(firstVertex);
		for (Edge edge : edgeList) {
			if (edge.edge.equals(secondVertex)) {
				flag = 1;
				break;
			}
		}
		return flag;
	}
	
	static LinkedList<Edge> edgelistinsert(Graph obj,String  currentVertex, LinkedList<String> vertex,   Scanner scan)
	{
		int flag = 0;
		String input,secondVertex;
		LinkedList<Edge> edgeList;
		
		if(obj.H.get(currentVertex)  !=null)
		{
			edgeList=obj.H.get(currentVertex);
		}
		else {
			edgeList=new LinkedList<>();
		}
		
		
		do {
			System.out.println("Is There any vertex coming out from vertex " + currentVertex + " press Y or N");
			input = scan.next();
			if (input.equals("Y")) {
				System.out.println("enter the other end vertex coming out from " + currentVertex);
				secondVertex = scan.next();
				flag=checkduplicate(edgeList,secondVertex);
				if (flag != 1) {
					if (vertex.contains(secondVertex)) {
							Edge temp2 = new Edge();
							temp2.edge = secondVertex;
							edgeList.add(temp2);
							insideinsert(obj,secondVertex,currentVertex);
							edgeCount=edgeCount+2;
					} else {
						System.out.println("Invalid vertex");
					}
				} else
					System.out.println("Duplicate vertex not allowed");
			}

		} while (!(input.equals("N")));
		
		return edgeList;
	}
	
	static int checkduplicate(LinkedList<Edge> edgeList, String edge)
	{
		for (Edge temp : edgeList) {
			if (temp.edge.equals(edge)) {
				return 1;
			}
		}		
		return 0;
	}
	
	static void iteratoredgedelete(LinkedList<Edge> edgeList,String vertex)
	{
		
		Iterator<Edge> iterator = edgeList.iterator();
		while (iterator.hasNext()) {
			if (iterator.next().edge.equals(vertex)) {
				iterator.remove();
				edgeCount--;
				break;
			}
		}
		
	}
	
	static void insideinsert(Graph obj,String secondVertex ,String currentVertex ) {
		if(obj.H.containsKey(secondVertex) ) {
			
			Edge edge = new Edge();
			edge.edge= currentVertex;
			obj.H.get(secondVertex).add(edge);
		}
		else {
			
			LinkedList<Edge> insideEdge = new LinkedList<>();
			Edge edge = new Edge();
			edge.edge= currentVertex;
			insideEdge.add(edge);
			obj.H.put(secondVertex, insideEdge);
			
		}
		
		
	}

}
```

Unweighted Graphs Using Linked Lists


A decade ago I was asked to find all possible permutations of a given string in
a software company interview . There were plenty of solutions available in various other blogs but nothing
was perfect and I felt that something could be improved in those existing algorithms . Although I was not able to give the right answer in the interview but  I want to share my thoughts on how to solve this complex problem in a unique manner. The question was tough and it requires lot of thought process to write the code for this given problem . Thank you for testing my IQ again and again . 

That's why I have written my own non recursive as well as recursive algorithm to solve this complex problem . I hope the solution is very clear and my algorithm is different and it does not do any swap operations  because it is not a sorting problem and neither my algorithm converts string to array which can be done with  StringBuilder() in Java or String split() in Javascript . It also handles strings with duplicate characters .


```javascript

/*

   Find permutations of a given string in recursive way original source code written by me 
   copyright information
   Author Name - Raj Gopal Bhallamudi
   Email - flame527@yahoo.com , rajgopal527@gmail.com
   Facebook - facebook.com/r5274
   Instagram - instagram.com/bhrajgopal
   Date - 26th June 2025

   */



let startsWith=[];


function permutationRecursive(start) {

    let newString, newRemainingString , length=start.length;

    for(let counter = 0; counter < length; counter++) {
        newString = start.charAt(counter);
        newRemainingString = start.substring(0, counter)+start.substring(counter + 1, length);
        if(startsWith.indexOf(newString) === -1) {
            permutationSubString(newString, newRemainingString);
            startsWith.push(newString);
        }

    }

}

function  permutationSubString(start, remainingString) {

    let newString, newRemainingString , length=remainingString.length;

    if(remainingString===""){
        console.log(start);
        return
    }

    for(let counter = 0; counter < length; counter++) {
        newString = start + remainingString.charAt(counter);
        newRemainingString = remainingString.substring(0, counter)+remainingString.substring(counter + 1, length);
        if(startsWith.indexOf(newString) === -1) {
            permutationSubString(newString, newRemainingString);
            if(newRemainingString!=="")
                startsWith.push(newString);
        }

    }



}

permutationRecursive("XYZ");



/*


    Author Name - Unknown 

   */


let startsWith=[];

function permutationRecursive(start, remainingString) {

    let newString, newRemainingString , length=remainingString.length;

    if(remainingString.length === 0 ) {
       console.log(start);
       return;
    }

    for(let counter = 0; counter < length; counter++) {
        newString = start + remainingString.charAt(counter);
        newRemainingString = remainingString.substring(0, counter)+remainingString.substring(counter + 1, length);
        if(startsWith.indexOf(newString) === -1) {
            permutationRecursive(newString, newRemainingString);
            if(newRemainingString.length!==0)
                startsWith.push(newString);
        }

    }


}

permutationRecursive("","XYZ")



/*
    Toughest Programming  Challenge
    Find permutations of a given string in non  recursive way including duplicate characters 
    copyright information
    Author Name - Raj Gopal Bhallamudi
    Email - flame527@yahoo.com , rajgopal527@gmail.com
    Facebook - facebook.com/r5274
    Instagram - instagram.com/bhrajgopal
    Date - 26th June 2025

 */

const startsWith = [];
const stack = [];
let result = ""

function permutationNonRecursive(start) {

    let firstChar,newString, newRemainingString, stringLength = start.length, length;

    for (let counter = 0; counter < stringLength; counter++) {

        firstChar = newString = start.charAt(counter);
        newRemainingString = start.substring(0, counter) + start.substring(counter + 1, stringLength);

        if (startsWith.indexOf(newString) === -1) {

            stack.unshift({newString, newRemainingString});
            while (stack.length > 0) {
                let {newString: start, newRemainingString: remainingString} = stack.shift();
                length = remainingString.length;
                    for (let innerCounter = 0; innerCounter < length; innerCounter++) {
                        newString = start + remainingString.charAt(innerCounter);
                        newRemainingString = remainingString.substring(0, innerCounter) +
                                                  remainingString.substring(innerCounter + 1, length);
                            if (newRemainingString.length === 0) {
                               result = result + newString + " ";
                               } else {
                            if (startsWith.indexOf(newString) === -1){
                                stack.unshift({newString, newRemainingString});
                                startsWith.push(newString);
                            }
                        }
                    }
            }
            startsWith.push(firstChar);
        }
    }

}


let string = "XYZ";

permutationNonRecursive(string);
console.log(result);





```


Permutations of given string



I have great experience in Full Stack developement . I have gained significant exposure
in NextJs framework for building fullstack react applications & I am capable of building
large scale web apps which look great , performance efficient and are very secure in nature . I can be the 
backbone of your trillion dollar business by becoming the Manager with main focus on building the front end user interface of 
your companies website and attract valuable clients with in minutes. Let it be any business the front end developers generate most of the revenue for any company by creating good looking websites  .  With many recent advancements in Reactjs library this technology is the most popular and almost used by many top companies in the world to create handsome websites. 

The blog that you are currently viewing is an outcome of my past two decades  day and night hardwork , 19 years ago I purchased a computer and started to learn programming , going through the painful online learning process , giving certification exam , continuosly learning new technologies and framework , preparing for interviews , which increased my weight by 20 kilos 🐘 . Nowadays I am focusing more on my health and fitness , trying to reduce my weight , in the past 6 months I have reduced my weight by 7 kilos .

Merely getting a first class computer science college degree from a well known university was not enough so I decided to build a big project , The actual developer journey starts after getting the graduation and post graduation degree . I worked like a machine with continues effort and focus on each and every big change that is required to make this existing project even more better , I finally feel that the blog now looks like a masterpiece .  I hope that my code base is completly safe and secure in Github repository and is not disclosed to anyone including my family members at any cost .



## Technical Specs

## Full stack framework Nextjs

## App router in Nextjs apps
- React server & client components , Working with server action , Triggering cache revalidations
- Setting Up & Using Parallel Routes , Working with Parallel Routes & Nested Routes , Intercepting Navigation & Using Interception Routes
- Combining Parallel & Intercepting Routes , Using & Understanding Route Groups , Performing Optimistic Updates With NextJS
- Understanding & Configuring Caching , Using the NextJS Image Component , User Authentication with Lucia
## File based routing in Nextjs apps
- Page pre rendering and data fetching for faster loading of nextjs apps and for search engine optimization
- Adding backend code with the help of api routes 
- Performance optimization of react & next apps
- Application wide state management with help of context api , react redux toolkit & custom hooks
- Working with forms and user input
- Working with nosql database Mongodb
- Deploying NextJs Apps to vercel 
- Adding Authentication to NextJs Apps using NextAuth

## Reactjs
- [Reactjs version 18.2](https://legacy.reactjs.org/docs/hooks-reference.html) , React router version 5 , React redux toolkit ,Framer motion

## Frontend 
- Styling react component using css modules 
- Styling react component using Tailwindcss


## Programming languages
Modern Javascript & Core Java 

## Backend
- Mysql
- Mongodb

## Work Experience 

- Company - [Cognizant](https://www.cognizant.com/)   \
  Client - [British Airways](https://www.britishairways.com)  \
  Year - 2013-2014  \
  Role - Backend developer

- Company - [Infosys](https://www.infosys.com)    \
  Client - [Oversea Chinese Banking Corporation Limited](https://www.ocbc.com)  \
  Year - 2021-2022  \
  Role - Front end developer 
  


## Education 

- [Masters](../images/posts/about-myself/mtech.jpeg) in computer science from [CBIT](https://www.cbit.ac.in) \
  affiliated to [OU](https://www.osmania.ac.in)  \
  year  2011-2013   \
  aggregate 70% 

- [Bachelors](../images/posts/about-myself/btech.jpeg) in computer science from [TKREC](https://tkrec.ac.in)  \
  affiliated to [JNTUH](https://www.jntuh.ac.in) \
  year  2006-2010 \
  aggregate 67% 

- Andhra Pradesh Board of Intermediate \
  Sri Chaitanya Junior College Asilmetta Visakhapatnam, Andhra Pradesh  \
  year 2003-2005 \
  aggregate 87% \
  Maths Physics Chemistry \
  11th & 12th standard [Intermediate](../images/posts/about-myself/inter.jpeg)
   
  

- Central Board Of Secondary Education \
  Kendriya Vidyalaya Central Reserve Police Force Barkas Hyderabad , Telangana  \
  year 2002-2003 \
  aggregate 63%  \
  10th standard  [Tenth](../images/posts/about-myself/tenth.jpeg)
  



## Birthplace
4 September 1988 \
St. Joseph's Hospital Bobbili, Vizianagaram , Andhra Pradesh


## Resume
- [Resume](../images/posts/about-myself/Raj.pdf) 

## Video profile


<style>
.iframe-container {
position: relative;
width: 100%;
padding-bottom: 56.25%;
height: 0;
overflow: hidden;
border-radius: 8px;
}

.iframe-container iframe {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
border: 0;
}
</style>

<div class="iframe-container">
<iframe width="560" height="315" src="https://www.youtube.com/embed/zPV_-MjZ3XY?si=zGHMZpfHEVGXcSaQ" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
</div>




About Myself


## Nextjs React full stack developer

In last three years since covid lockdown 2020 , I planned my future and I decided to start my software career as a React NextjS full stack developer & achieved my goal of becoming a full stack developer in 2023 . I decided to start my career as [React and Nextjs](https://nextjs.org) software developer because these are the frameworks and libraries built & supported by tech giants like Meta . 
This course is developed by the best instructor in world [Maximilian Schwarzmüller](https://www.udemy.com/user/maximilian-schwarzmuller/) who explained all the features of React and Nextjs framework in great detail with many projects included in it which helps to gain real time experience . Maximilian is helping many students to earn a living by teaching all the hotcake technologies  so that students can get  job as a web developer in big tech companies  . 

A decade ago when I completed my graduation there were no popular libraries like Reactjs and neither there were any full stack framework like Nextjs to simplify developers life  that avoids all the unnecessary work done by javascript developer &  upgrading my skillset was the biggest challenge for me in past few years since covid lockdown . 

Learning Nextjs was challenging because I had to learn Reactjs first and then I started learning Nextjs fullstack framework built on Reactjs . If you want to have mastery in backend and want to learn how to work with both sql and no-sql database then this course is 
great choice . I dont believe in showing fake experience & bluffing and this blog is a solid proof of my mastery in full stack web development and I alone can become top level Manager and can handle a team size of many members to build large scale web applications   .  



![Certification](Nextjs.png)

[NextJS React Certified Developer](https://www.udemy.com/certificate/UC-06308dc9-8bfa-4624-a74f-975301bdad9b/).

[Meet thousands of beautiful websites built with Next.js by Vercel](https://nextjs.org/showcase)

## Css developer (incl. Flexbox, Grid & Sass)

I really enjoyed the course and there were many things that I found helpful . Here I learned how to build a
website from scratch .I learned  how to create a web hosting website with the help of Flexbox and also 
all the core concepts of webdesign like positioning, sizes and units , adding  responsiveness ,Animation , Grids & Sass  were covered . Learning web design is the most challenging thing and  Web design  is a must for any  front end developer . You can learn all the basics required to build great looking decent modern websites but not the cartoon network butterfly pokemon stuff , nor the scalable vector graphics  animation and filter- with HTML, CSS & Javascript. I know the changes that I have made are a bit more advanced but I feel that the changes did not cross its limits and the blog which I have built looks decent and simple without much complication . I have limited the usage of [framer motion](https://youtu.be/ILxNdOtKbNQ) library to draw lines , [to animate text](https://www.josephcollicoat.com/articles/animating-text-with-the-intersection-observer-api-and-framer-motion)  , to add parallax effect  and control the appearence and disappearence of elements on web page  . 

One thing I really liked in this course is that there are lot of quizzes in the modules  for filteration purpose & performance evaluation and I could also compare my answers with the actual answer after completing the project assignments. This certificate is the proof of my mastery in front end web development . Css developers are high in demand because whatever may be the framework React, Vue ,Angular , or websites that dont even use any framework or front end libraries all the projects heavily rely on the CSS developer to design their web application . Css developers dont write unnecessary code & have complete control when compared to Bootstrap or Tailwindcss developers

![Certification](Css.jpg)

[Css developer (incl. Flexbox, Grid & Sass)](https://www.udemy.com/certificate/UC-773da908-9792-43c3-9723-fddc64ec721e/).








Certifications


One may feel that it's really difficult to create a graph in runtime but now this difficult problem
is solved . Now a graph can be created in runtime and I have written a Java code to implement 
Bellman ford algorithm using linked lists . I preferred Java over other programming languages because Java has support for powerful collections framework , Java does not use pointers but written in C , Java program can be converted to C program , let it be any programming language the logic is always the same I hope you got my point ,  Java comes with power of Hadoop which can process terrabytes of data , Java is platform independent and its more convenient to write complex  logic in Java  ,Java is used in Billions of devices and if each device pays me minimum 4 dollars for using my algorithm then I would become a Billionaire and reach my destination .  I hope this post on Graphs using Linked Lists will clear all the doubts of how to create a Linked List and how to implement any graph algorithm using Linked Lists . 


I did lot of hardwork approximately 4 years research work and came up with 
the solution for the most difficult problem in the field of Graph Theory . With Array based implementation
its not possible to add & remove vertices or edges inside Graph but with Linked lists its possible to add and remove 
vertices or edges and apply Graph algorithm . [Here are some of the important Graph Theory applications in day to day life](https://en.wikipedia.org/wiki/Graph_theory#Applications) .


To minimize LinkedHashMap & HashMap resizing:
Set an appropriate initial capacity if you know the expected number of entries.
Adjust the load factor if needed 


```java

/* copyright information 
   Author Name - Raj Gopal Bhallamudi
   Email - flame527@yahoo.com , rajgopal527@gmail.com
   Facebook - facebook.com/r5274
   Instagram - instagram.com/bhrajgopal
   */


import java.util.LinkedList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Set;
import java.util.Iterator;
import java.util.Scanner;
import java.util.InputMismatchException;


	

class Edge {
	String edge;
	int weight;
}

class Graph {
	LinkedHashMap<String, LinkedList<Edge>> H = new LinkedHashMap<>();
	HashMap<String, LinkedList<String>> inside = new HashMap<>();
	HashMap<String, Integer> D = new HashMap<>();
	HashMap<String, String> P = new HashMap<>();
}

public class Example {
	
	static int vertexCount=0;
	static int edgeCount=0;

	public static void main(String[] args) {
		
		Runtime runtime = Runtime.getRuntime();

      
        runtime.gc();
        long before = runtime.totalMemory() - runtime.freeMemory();

		Graph graphObject = null;
		bellmanFord(graphObject);
		
		runtime.gc();
        long after = runtime.totalMemory() - runtime.freeMemory();

        System.out.println("\n \n Total Memory used in bytes " + (after - before) );

	}

	static void bellmanFord(Graph graphObject) {
		Scanner scan = new Scanner(System.in);

		if (graphObject == null)
			graphObject = new Graph();

		int input = 0;
		
		

		do {
			System.out.println(
					"\n\n\n\n 1.create graph  2.print graph   3.insert vertex  4.insert edge\n 5.delete vertex   6.delete edge   7.search vertex   8.search edge \n 9.Bellman ford  10.Delete graph 11.completed ");

			try {
			input = scan.nextInt();
			}
			catch (InputMismatchException e) {
	            scan.nextLine(); 
	        }
			
			switch (input) {

			case 1:
				if (graphObject.H.size() > 0)
					System.out.println("Graph already created");
				else
					creategraph(graphObject, scan);
				break;

			case 2:
				if (graphObject.H.size() > 0)
					display(graphObject);
				else
					System.out.println("Graph is empty");
				break;

			case 3:
				if (graphObject.H.size() > 0)
					insertvertex(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 4:
				if (graphObject.H.size() > 0)
					insertedge(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 5:
				if (graphObject.H.size() > 0)
					deletevertex(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 6:
				if (graphObject.H.size() > 0)
					deleteedge(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 7:
				if (graphObject.H.size() > 0)
					searchvertex(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 8:
				if (graphObject.H.size() > 0)
					searchedge(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 9:
				if (graphObject.H.size() > 0)
					Mainbell(graphObject, scan);
				else
					System.out.println("Graph is empty");
				break;

			case 10:
				if (graphObject.H.size() > 0)
					del(graphObject);
				else
					System.out.println("Graph is empty");
				break;

			case 11:
				break;

			default:
				System.out.println("Invalid input received please try again");
				break;
			}
		} while (input != 11);
		 
		

	}

	static void display(Graph graphObject) {
		System.out.println("\n CREATED GRAPH IS \n");
		for (String vertex : graphObject.H.keySet()) {
			LinkedList<Edge> edges = graphObject.H.get(vertex);
			if (edges.size() > 0) {
				for (Edge edge : edges)
					System.out.print("(" + vertex + "," + edge.edge + ")=" + edge.weight + " ");
				System.out.println();
			} else {
				System.out.print("(" + vertex + ")");
				System.out.println();
			}	
		}
		System.out.println("\n\n Total number of vertices = "+vertexCount);
		System.out.println(" Total number of edges = "+edgeCount);
	}

	static void iss(String s, Graph obj) {
		Set<String> vertices = obj.H.keySet();

		for (String vertex : vertices) {
			obj.D.put(vertex, Integer.MAX_VALUE);
			obj.P.put(vertex, "NIL");
		}
		obj.D.put(s, 0);
	}

	static void relax(String u, String v, Graph obj, int weight) {

		int uValue = obj.D.get(u);
		int vValue = obj.D.get(v);
		int total  = uValue + weight ;
		
		if ( (uValue !=  Integer.MAX_VALUE ) && (vValue > total)) {
			obj.D.put(v, total);
			obj.P.put(v, u);
		}
		
	}

	static int cycletest(String u, String v, Graph obj, int weight) {
		
		if ( (obj.D.get(u) !=  Integer.MAX_VALUE ) && ( obj.D.get(v) > obj.D.get(u) + weight)) {
			return 0;
		}

		return 1;
	}

	static int bell(String s, Graph obj) {
		int k = 1;
		iss(s, obj);
		Set<String> vertices = obj.H.keySet();
		

		if (!obj.H.get(s).isEmpty()) {
			for (int i = 0; i < vertices.size() - 1; i++) {
				
				for (String u : vertices) {
					LinkedList<Edge> edges = obj.H.get(u);
					for (Edge edge : edges) {
						relax(u, edge.edge, obj, edge.weight);
					}
				}
			}

			for (String vertex : vertices) {
				if (k != 0) {
					LinkedList<Edge> edges = obj.H.get(vertex);
					for (Edge edge : edges) {
						k = cycletest(vertex, edge.edge, obj, edge.weight);
						if (k == 0)
							break;
					}
				}
			}
		}
		return k;
	}

	static void printpath(String s, String v, Graph obj) {
		if (s.equals(v))
			System.out.print(s);
		else {
			if (obj.P.get(v).equals("NIL"))
				System.out.println("No path exists from " + s + " to " + v);
			else {
				printpath(s, obj.P.get(v), obj);
				System.out.print(" " + v);
			}
		}
	}

	static void mindis(Graph obj, String s) {
		Set<String> i = obj.D.keySet();
		for (String j : i) {
			System.out.println("Minimum distance between (" + s + "," + j + ")=" + obj.D.get(j));
		}
	}

	static void creategraph(Graph obj, Scanner scan) {
		String input, invalid = "END";
		LinkedList<String> vertex = new LinkedList<>();
		do {
			System.out.println("enter a vertex else type END");
			input = scan.next();
			if (!(input.equals(invalid)))
				if (!(vertex.contains(input))) {
					vertex.add(input);
					vertexCount++;
				} else {
					System.out.println("Duplicate vertex not allowed");
				}
		} while (!input.equals(invalid));

		for (int current = 0; current < vertex.size(); current++) {
			String currentVertex = vertex.get(current);
			LinkedList<Edge> edgeList = new LinkedList<>();
			edgelistinsert(obj,currentVertex,vertex,edgeList,scan);
			obj.H.put(currentVertex, edgeList);
		}
	}

	static void Mainbell(Graph obj, Scanner sc) {
		String s, d;
		System.out.println("\n enter source vertex ");
		s = sc.next();
		
	   if(obj.H.keySet().contains(s)) {
			int k = bell(s, obj);
			if (k == 0) {
				System.out.println("-ve weight cycle");
			} else {
				mindis(obj, s);
				System.out.println("\n enter destination vertex ");
				d = sc.next();

				System.out.println("\nBellman fords shortest path between source and destination is \n");
				printpath(s, d, obj);
			}
	   }
	   else {
		   System.out.println("\n The entered source vertex doesnt exist  \n");
	   }
	}

	static void insertvertex(Graph obj, Scanner sc) {
		String currentVertex;
		System.out.println("Enter a vertex");
		currentVertex = sc.next();
		if (obj.H.containsKey(currentVertex))
			System.out.println("vertex already present");
		else {
			LinkedList<Edge> edgeList = new LinkedList<>();
			LinkedList<String> vertex = new LinkedList<>(obj.H.keySet());
			edgelistinsert(obj,currentVertex,vertex,edgeList,sc);
			obj.H.put(currentVertex , edgeList);
			vertexCount++;
		}

	}

	static void insertedge(Graph obj, Scanner sc) {
		String firstVertex, secondVertex;
		int duplicateFlag, weight=0;
		System.out.println("Enter first end vertex");
		firstVertex = sc.next();
		if (obj.H.containsKey(firstVertex)) {
			System.out.println("Enter second end vertex");
			secondVertex = sc.next();
			if (obj.H.containsKey(secondVertex)) {
				LinkedList<Edge> edgeList = obj.H.get(firstVertex);
				duplicateFlag = search(obj, firstVertex, secondVertex);
				if (duplicateFlag == 1) {
					System.out.println("edge already present");
				} else {
					System.out.println(" enter the weight of (" + firstVertex + "," + secondVertex + ")");
					try {
						 weight = sc.nextInt();
						 Edge temp2 = new Edge();
						 temp2.edge = secondVertex;
					     temp2.weight = weight;
						 edgeList.add(temp2);
						 insideinsert(obj,secondVertex,firstVertex);
						 edgeCount++;
					}
					 catch (InputMismatchException e) {
			                System.out.println("Invalid input! Please enter a valid integer.");
			                sc.nextLine();
			            } 
					
				}
			} else {
				System.out.println("invalid second end vertex");
			}

		} else {
			System.out.println("invalid first end vertex");
		}
	}

	static void searchedge(Graph obj, Scanner sc) {
		String firstVertex, secondVertex;
		int flag = 0;
		System.out.println("Enter first end vertex");
		firstVertex = sc.next();
		if (obj.H.containsKey(firstVertex)) {
			System.out.println("Enter second end vertex");
			secondVertex = sc.next();
			if (obj.H.containsKey(secondVertex)) {
				flag = search(obj, firstVertex, secondVertex);
				if (flag == 1) {
					System.out.println("edge is present");
					return;
				}
			} else {
				System.out.println("Invalid second vertex");
				return;
			}
		} else {
			System.out.println("Invalid first vertex");
			return;
		}
		 if (flag == 0) {
			System.out.println("edge is not present");
		}
	}


	static void searchvertex(Graph obj, Scanner sc) {
		String vertex;
		System.out.println("Enter a vertex");
		vertex = sc.next();
		if (obj.H.containsKey(vertex)) {
			System.out.println("vertex present");
		} else {
			System.out.println("vertex not present");
		}

	}

	static void deletevertex(Graph obj, Scanner sc) {
		String vertex;
		System.out.println("Enter a vertex");
		vertex = sc.next();
		if (obj.H.containsKey(vertex)) {
			
			LinkedList<Edge> edge =obj.H.get(vertex);
			edgeCount = edgeCount - edge.size();
			
			obj.H.remove(vertex);
			LinkedList<String> vertices = obj.inside.get(vertex);
			
			Iterator<String> str = vertices.iterator();
			while (str.hasNext()) {
				LinkedList<Edge> edgeList = obj.H.get(str.next());
				iteratoredgedelete(edgeList,vertex);
				str.remove();
			}
			
			
			if(obj.inside.containsKey(vertex)) 
				obj.inside.remove(vertex);
			if (obj.D.containsKey(vertex))
				obj.D.remove(vertex);
			if (obj.P.containsKey(vertex))
				obj.P.remove(vertex);
			
			vertexCount--;

		} else {
			System.out.println("vertex not present");
		}
	}

	static void deleteedge(Graph obj, Scanner sc) {
		String firstVertex, secondVertex;
		System.out.println("Enter first end vertex");
		firstVertex = sc.next();
		if (obj.H.containsKey(firstVertex)) {
			System.out.println("Enter second end vertex");
			secondVertex = sc.next();
			if (obj.H.containsKey(secondVertex)) {

				int flag = search(obj, firstVertex, secondVertex);
				if (flag == 1) {
					LinkedList<Edge> edgeList = obj.H.get(firstVertex);
					iteratoredgedelete(edgeList,secondVertex);
					obj.inside.get(secondVertex).remove(firstVertex);
					
				} else {
					System.out.println("edge not present");
				}
			} else {
				System.out.println("invalid second vertex");
			}
		} else {
			System.out.println("invalid first vertex");
		}

	}

	static void del(Graph obj) {
		Set<String> vertices = obj.H.keySet();
		for (String vertex : vertices)
			obj.H.remove(vertex);
	}


	static int search(Graph obj, String firstVertex, String secondVertex) {
		int flag = 0;
		LinkedList<Edge> edgeList = obj.H.get(firstVertex);
		for (Edge edge : edgeList) {
			if (edge.edge.equals(secondVertex)) {
				flag = 1;
				break;
			}
		}
		return flag;
	}
	
	static void edgelistinsert(Graph obj,String  currentVertex, LinkedList<String> vertex, LinkedList<Edge> edgeList , Scanner scan)
	{
		int flag = 0,weight=0;
		String input,secondVertex;
		do {
			System.out.println("Is There any vertex coming out from vertex " + currentVertex + " press Y or N");
			input = scan.next();
			if (input.equals("Y")) {
				System.out.println("enter the other end vertex coming out from " + currentVertex);
				secondVertex = scan.next();
			
				flag=checkduplicate(edgeList,secondVertex);
				
				if (flag != 1) {
					if (vertex.contains(secondVertex)) {
						System.out.println("enter weight of edge(" + currentVertex + "," + secondVertex+ ")");
						try {
							weight = scan.nextInt();
							Edge temp2 = new Edge();
							temp2.edge = secondVertex;
							temp2.weight = weight;
							edgeList.add(temp2);
							insideinsert(obj,secondVertex,currentVertex);
							edgeCount++;
						}
						catch (InputMismatchException e) {
			                System.out.println("Invalid input! Please enter a valid integer.");
			                scan.nextLine(); 
			            } 
					} else {
						System.out.println("Invalid vertex");
					}
				} else
					System.out.println("Duplicate vertex not allowed");
			}

		} while (!(input.equals("N")));
	}
	
	static int checkduplicate(LinkedList<Edge> edgeList, String edge)
	{
		for (Edge temp : edgeList) {
			if (temp.edge.equals(edge)) {
				return 1;
			}
		}		
		return 0;
	}
	
	static void iteratoredgedelete(LinkedList<Edge> edgeList,String vertex)
	{
		
		Iterator<Edge> iterator = edgeList.iterator();
		while (iterator.hasNext()) {
			if (iterator.next().edge.equals(vertex)) {
				iterator.remove();
				edgeCount--;
				break;
			}
		}
		
	}
	
	static void insideinsert(Graph obj,String secondVertex ,String currentVertex ) {
		if(obj.inside.containsKey(secondVertex) ) {
			obj.inside.get(secondVertex).add(currentVertex);
		}
		else {
			LinkedList<String> inside = new LinkedList<>();
			inside.add(currentVertex);
			obj.inside.put(secondVertex, inside);
		}
	}

}




```


Graphs Using Linked Lists


Dear friends if you are preparing for product based companies interview then 
this tough question may be asked in the interview . The requirement is that you will 
be given a linked lists and you will  be asked to reverse the linked lists by 
breaking it into smaller chunks . 

For example if I have a linked list with 11 items 

1 2 3 4 5 6 7 8 9 10 11

and if  list is divided into 3 size chunk then
we will get the following output 

3 2 1 6 5 4 9 8 7 11 10


Dont get tensed  because even I was not able to give the right 
answer in the interview but later I came up with a solution with the help 
of my subconscious mind and which is easy to remember  . I have written
a java code to solve this problem using java collection framework . 
I have written a non recursive solution to solve this problem and I hope
you will like this solution .








```java

/* copyright information 
   Author Name - Raj Gopal Bhallamudi
   Email - flame527@yahoo.com , rajgopal527@gmail.com
   Facebook - facebook.com/r5274
   Instagram - instagram.com/bhrajgopal
   */
   
   

import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

class Oracle {
    public static void main(String[] args) {

      List<Integer> list = new LinkedList<Integer>();

        list.add(1);
        list.add(2);
        list.add(3);
        list.add(4);
        list.add(5);
        list.add(6);
        list.add(7);
        list.add(8);
        list.add(9);
        list.add(10);
        list.add(11);
        
        int listSize=list.size();
        int k = 3; // chunk size
        
        for (int i = 0; i < listSize; i += k) {
        if(i+k<=listSize)
            Collections.reverse(list.subList(i, i + k));
                else
            Collections.reverse(list.subList(i, listSize));
        }
        System.out.println(list);
    }
}
   
   
   
```


Paranormal activity 1

Paranormal activity 2

Unweighted Graphs Using Linked Lists

Permutations of given string

About Myself

Certifications

Graphs Using Linked Lists

Reverse Kset Linked Lists