Question

**I asked this question once, and the answer completely ignored a majority of the rules listed on this. PLEASE read what is necessary before giving an answer.

**NEITHER answer when searching for this question has a ParityChain class, a ParityChainDemo class or even include some of the stated requirements (such as hasError method).

**Parity bit was specified by instructor to be LEFT most bit in chain

Done in Java using Apache NetBeans IDE 11.2 -- Objectives: To create a data structure with underlying linked chain; To utilize and implement code dealing with parity big codes for error detection; To read data from file

**The other answer when searching for this question does not have a ParityChain class, a ParityChainDemo class or even include some of the stated requirements (such as hasError method).

**Parity bit was specified by instructor to be LEFT most bit in chain

In this project, you will read bits (0s and 1s) from a file. On each line there will be 8 bits. You must read them into memory and store each bit in a node in a linked chain.

We will use an error detection technique called parity bits. We will specifically use even parity. So, 7 bits represent data and one bit represents the parity. What this means is if there are, for example, an odd number of 1s in the actual data, the parity bit (first bit) is set to 1 to make the number of 1s even. If there is an even number of 1s in the actual data, then we set the parity bit (first bit) to 0.

We know there is an error if the byte (8 bits) we receive ever has an odd number of ones in it, because there should be an even number.

So the input on a single line might contain the following:

0 1 1 1 1 1 0 1

Since we read this and found six 1s, this byte is assumed to be error free (in our scheme.)

But if we read the following:

1 1 1 0 1 1 1 1

By the time we get it, there are seven 1s, so that’s an odd number of 1s. This means there must be an error somewhere.

Your assignment does not require you to fix the errors. However, your ParityChain class must know if it has an error or not (hasError method, which returns true or false). Also, you should be able to tell the chain to print out its bits.

You must read an arbitrary number of bytes (lines of 8 bits with spaces in between) from file. Each “firstNode” may be placed into an ArrayList, but the enter chain itself must be linked, and made manually by you (with nodes.)

Answer 1

Problem statement:

Your assignment does not require you to fix the errors. However, your ParityChain class must know if it has an error or not (hasError method, which returns true or false). Also, you should be able to tell the chain to print out its bits.

You must read an arbitrary number of bytes (lines of 8 bits with spaces in between) from file. Each “firstNode” may be placed into an ArrayList, but the enter chain itself must be linked, and made manually by you (with nodes.)

Explanation:

A Node.java class has been created for each bit of the byte. An arraylist is used to keep track of the arbitrary number of bytes that have to be read from the file.

The implementation for the linked node is there in the StackLinkedList.java class. It also calculates and error in the method hasError method, which returns true or false.

For the sake of test a file input.txt has been used.

The java classes and the input file and the outputs have been given below. Please feel free to reach out if you have questions.

Java classes

##############################################################################

Node.java

public class Node {

   int data;

   Node link;

   public Node () {

   }

   public Node(int data, Node link) {

   this.data = data;

   this.link = link;

   }

}

##############################################################################

StackLinkedList.java

public class StackLinkedList {

Node top;

StackLinkedList() {

   this.top = null;

}

public void push(int x) {

   Node node = new Node();

   node.data = x;

   node.link = top;

   top = node;

}

public boolean isEmpty() {

   return top == null;

}

public int peek() throws Exception {

   if (!isEmpty()) {

   return top.data;

   }

   else {

   throw new Exception();

   }

}

public void pop() {

   if (top == null) {

   System.out.print("\nStack Underflow");

   return;

   }

   top = (top).link;

}

public void displayChain() {

   if (top == null) {

   System.out.println("[]");

   }

   else {

   Node temp = top;

   String str = "[";

   while (temp != null) {

   str += temp.data + ", ";

   temp = temp.link;

   }

   str = str.trim();

   str = str.substring(0,str.length()-1);

   str += "]";

   System.out.println(str);

   }

}

public int size() {

int count = 0;

Node temp = top;

   while (temp != null) {

   temp = temp.link;

   count++;

   }

return count;

}

public boolean hasError() {

int count = 0;

Node temp = top;

   while (temp != null) {

   if(temp.data == 1)

   count++;

   temp = temp.link;

   }

return count%2 == 1;

}

}

##############################################################################

ParityChain.java

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Scanner;

public class ParityChain {

static ArrayList<StackLinkedList> list = new ArrayList<StackLinkedList>();

public static void main(String[] args) throws IOException {

File file = new File("input.txt");

Scanner sc = new Scanner(file);

while (sc.hasNextLine()) {

String input = (sc.nextLine());

StackLinkedList stack = new StackLinkedList();

for(int i=0;i<input.length();i++) {

if(input.charAt(i) != ' ') {

stack.push(Integer.parseInt(String.valueOf(input.charAt(i))));

}

}

list.add(stack);

}

displayErrors();

}

public static void displayErrors() {

for(int i = 0; i<list.size(); i++) {

StackLinkedList linkedList = list.get(i);

linkedList.displayChain();

System.out.println("Does bytes have error : " + linkedList.hasError() + "\n");

}

}

}

Input file

##############################################################################

input.txt

0 1 1 1 1 1 0 1

1 1 1 0 1 1 1 1

1 1 0 0 1 1 1 1

1 1 1 1 1 1 1 1

1 0 1 0 1 0 1 1

0 1 0 0 1 0 1 1

##############################################################################

Output:

[1, 0, 1, 1, 1, 1, 1, 0]

Does bytes have error : false

[1, 1, 1, 1, 0, 1, 1, 1]

Does bytes have error : true

[1, 1, 1, 1, 0, 0, 1, 1]

Does bytes have error : false

[1, 1, 1, 1, 1, 1, 1, 1]

Does bytes have error : false

[1, 1, 0, 1, 0, 1, 0, 1]

Does bytes have error : true

[1, 1, 0, 1, 0, 0, 1, 0]

Does bytes have error : false

##############################################################################

Screenshots:

A Problems @ Javadoc Declaration Console X <terminated> Parity Chain [Java Application] /Library/Java/JavaVirtual Machines/jdk-11.0.1.jdk/Contents/Home/bin/java (23-Mar-2020, 2:08:15 am) [1, 0, 1, 1, 1, 1, 1, 0] Does bytes have error : false [1, 1, 1, 1, 0, 1, 1, 1] Does bytes have error : true [1, 1, 1, 1, 0, 0, 1, 1] Does bytes have error : false [1, 1, 1, 1, 1, 1, 1, 1] Does bytes have error : false [1, 1, 0, 1, 0, 1, 0, 1] Does bytes have error : true [1, 1, 0, 1, 0, 0, 1, 0] Does bytes have error: false