Question

Using java Create a simple queue class and a simple stack class. The queue and stack should be implemented as a linked list.

Create three functions that utilize these data structures

Write a function that opens a text file and reads its contents into a stack of characters. The program should then pop the characters from the stack and save them in a second text file. The order of the characters saved in the second file should be the reverse of their order in the first file.

Write a function that opens a text file and reads its contents into a queue of characters. The program should then dequeue each character, convert it to uppercase, and store it in a second file.

Write a function that opens two text files and reads their contents into two separate queues. The program should then determine whether the files are identical by comparing the characters in the queues. When two nonidentical characters are encountered, the program should display a message indicating that the files are not the same. If both queues contain the same set of characters, a message should be displayed indicating that the files are identical. Create a driver program to test the functions.

Answer 1

Note: Please make sure that the files are saved with the correct name as mentioned below.

Program screenshots:

Node.java // Define the Node class. public class Node // Declare the variables. public char info; public Node next; // Define the default constructor. public Node() info = ''; next = null; // Define the parameterized constructor. public Node (char ch) { info = ch; next = null;

Stack.java // Define Stack class. public class Stack // Declare the private members. private Node head; // Define the default constructor. public Stack() head = null; // Define a method to insert an element // in the stack. public void push(char ch) // Create a new node if the head is null. if(head == null) head = new Node(ch; // Otherwise, create a new node and add // it at the head position. else Node temp = new Node(ch); temp.next = head; head = temp;

// Define a method to remove an element from // the stack. public void pop() . // Return if the head is null. if(head == null) { return; // Otherwise, move the head to the next node. else head = head.next; // Define a method to display the stack. public void display ( ) { Node temp = head; // Start a loop to traverse the list. while(temp != null) System.out.print(temp.info); temp = temp.next; System.out.println(); // Define a method to return the // top element of the stack. public char top() return head.info; // Define a method to check if the // stack is empty or not. public boolean isempty() return head == null;

Queue.java // Define the class Queue. public class Queue // Declare the private members. private Node head; // Define the default constructor. public Queue () head = null; // Define a method to insert an element // in the queue. public void enqueue (char ch) // Create a new node if the head is null. if(head == null) head = new Node(ch); // Otherwise, move to the end of the list // and add a new node. else { Node temp = head; while(temp.next != null) temp = temp.next; temp.next = new Node(ch); // Define a method to remove an element // from the queue. public void dequeue () // Return if the head is null. if(head == null) return;

// Otherwise, move the head to the // next node else head = head.next; // Define a method to display the queue. public void display ( ) Node temp = head; // Start the loop to traverse the list. while(temp != null) System.out.print(temp.info); temp = temp.next; System.out.println(); // Define a method to return the front // element of the queue. public char front() { return head.info; // Define a method to check if the // queue is empty or not. public boolean isempty(). return (head == null);

Main.java // Import the required packages. import java.io.*; import java.util.Scanner; // Define the Main class. public class Main { // Define a method to copy the content of one file // into another using a stack. public static void parti() throws Exception // Create a stack. Stack myStack = new Stack(); // Open the input file in read mode. File input = new File("input.txt"); Scanner infile = new Scanner(input); // Start the loop to read the file. while(infile.hasNextLine()) // Store the line in a string. String line = infile.nextLine(); // Start the loop to travese the line. for(char ch: line.toCharArray ( ) // Push the character in the stack. myStack.push(ch); // Add a new line character in the stack. if(infile.hasNextLine()). myStack.push('\n'); // close the input file. infile.close(); // Open the file in write mode. FileWriter output = new FileWriter("part1_output.txt"); BufferedWriter outfile = new BufferedWriter(output);

// Start the loop to traverse the stack. while(!my Stack.isempty()) // Write the top character of the stack // in the file. outfile.write(myStack.top()); // Remove the element from the stack. myStack.pop(); // Close the output file. outfile.close(); // Define a method to convert all the characters // of a file to uppercase using a queue. public static void part2() throws Exception // Create a queue. Queue my Queue = new Queue (); // Open the file in read mode. File input = new File("input.txt"); Scanner infile = new Scanner(input); // Start the loop to read the file. while(infile.hasNextLine()). { // Store the line in a string. String line = infile.nextLine(); // Start the loop to traverse the string. for(charch: line.toCharArray()) // Insert the character in the queue. my Queue. enqueue (ch); // Add a nextline character in the queue. if(infile.hasNextLine()). { my Queue. enqueue ('\n'); // Close the input file. infile.close();

// Open the file in write mode. FileWriter output = new FileWriter("part2_output.txt"); BufferedWriter outfile = new BufferedWriter(output); // Start the loop to traverse the queue. while( ! myQueue. i sempty()) // Store the first element. char ch = myQueue. front(); // If the current character is a letter, // convert it to uppercase and write it // in the file. if(Character.isLetter(ch)) outfile.write(Character.toUpperCase(ch)); // Otherwise, write the character in the file. else { outfile.write(ch); // Remove the character from the queue. my Queue. dequeue(); // Close the output file. outfile.close(); // Define a method to compare the content of // 2 files using a queue. public static void part3() throws Exception // Create 2 queues. Queue myQueue1 = new Queue (); Queue myQueue2 = new Queue (); // Open the file in read mode. File input = new File("part3_input1.txt"); Scanner infile = new Scanner(input);

// Start the loop to store the content // of the file in the first queue. while(infile.hasNextLine()). { String line = infile.nextLine(); for(charch: line.toCharArray ( )) my Queuel.enqueue(ch); } if(infile.hasNextLine()) my Queuel.enqueue('\n'); infile.close(); // Open the second file in read mode. input = new File("part3_input2.txt"); infile = new Scanner(input); // Start the loop to store the content // of the file in the second queue. while(infile.hasNextLine()) String line = infile.nextLine(); for(char ch: line.toCharArray ( ) w my Queue 2.enqueue(ch); if(infile.hasNextLine()) myQueue 2.enqueue('\n'); infile.close();

// Start the loop to traverse both the queue. while( ! myQueuel.isempty() || ! myQueue2.isempty()) // Display the error message if the characters // does not match. if(my Queuel. front() != myQueue2.front()) System.out.println("The files are not the same."); return; // Remove the character from both the queue. my Queuel.dequeue(); my Queue2. dequeue(); // Display the result. System.out.println("The files are identical."); // Define the main() method. public static void main(String[] args) throws Exception // Call the methods to test. part1(); part2(); System.out.print("Result for part 3: "); part3();

Sample output:

Result for part 3: The files are identical.

Sample output files:

part1_output.txt:

54321 .enil elpmas a si siht

part2_output.txt:

THIS IS A SAMPLE LINE. 12345

Node.java

// Define the Node class.

public class Node

{

    // Declare the variables.

    public char info;

    public Node next;

    // Define the default constructor.

    public Node()

    {

        info = ' ';

        next = null;

    }

    // Define the parameterized constructor.

    public Node(char ch)

    {

        info = ch;

        next = null;

    }

}

Stack.java

// Define Stack class.

public class Stack

{

    // Declare the private members.

    private Node head;

    // Define the default constructor.

    public Stack()

    {

        head = null;

    }

    // Define a method to insert an element

    // in the stack.

    public void push(char ch)

    {

        // Create a new node if the head is null.

        if(head == null)

        {

            head = new Node(ch);

        }

        // Otherwise, create a new node and add

        // it at the head position.

        else

        {

            Node temp = new Node(ch);

            temp.next = head;

            head = temp;

        }

    }

    // Define a method to remove an element from

    // the stack.

    public void pop()

    {

        // Return if the head is null.

        if(head == null)

        {

            return;

        }

        // Otherwise, move the head to the next node.

        else

        {

            head = head.next;

        }

    }

    // Define a method to display the stack.

    public void display()

    {

        Node temp = head;

        

        // Start a loop to traverse the list.

        while(temp != null)

        {

            System.out.print(temp.info);

            temp = temp.next;

        }

        System.out.println();

    }

    // Define a method to return the

    // top element of the stack.

    public char top()

    {

        return head.info;

    }

    // Define a method to check if the

    // stack is empty or not.

    public boolean isempty()

    {

        return head == null;

    }

}

Queue.java

// Define the class Queue.

public class Queue

{

    // Declare the private members.

    private Node head;

    // Define the default constructor.

    public Queue()

    {

        head = null;

    }

    // Define a method to insert an element

    // in the queue.

    public void enqueue(char ch)

    {

        // Create a new node if the head is null.

        if(head == null)

        {

            head = new Node(ch);

        }

        // Otherwise, move to the end of the list

        // and add a new node.

        else

        {

            Node temp = head;

            while(temp.next != null)

            {

                temp = temp.next;

            }

            temp.next = new Node(ch);

        }

    }

    // Define a method to remove an element

    // from the queue.

    public void dequeue()

    {

        // Return if the head is null.

        if(head == null)

        {

            return;

        }

        // Otherwise, move the head to the

        // next node.

        else

        {

            head = head.next;

        }

    }

    // Define a method to display the queue.

    public void display()

    {

        Node temp = head;

        // Start the loop to traverse the list.

        while(temp != null)

        {

            System.out.print(temp.info);

            temp = temp.next;

        }

        System.out.println();

    }

    // Define a method to return the front

    // element of the queue.

    public char front()

    {

        return head.info;

    }

    // Define a method to check if the

    // queue is empty or not.

    public boolean isempty()

    {

        return (head == null);

    }

}

Main.java

// Import the required packages.

import java.io.*;

import java.util.Scanner;

// Define the Main class.

public class Main

{

    // Define a method to copy the content of one file

    // into another using a stack.

    public static void part1() throws Exception

    {

        // Create a stack.

        Stack myStack = new Stack();

        // Open the input file in read mode.

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

        Scanner infile = new Scanner(input);

        // Start the loop to read the file.

        while(infile.hasNextLine())

        {

            // Store the line in a string.

            String line = infile.nextLine();

            // Start the loop to travese the line.

            for(char ch: line.toCharArray())

            {

                // Push the character in the stack.

                myStack.push(ch);

            }

            // Add a new line character in the stack.

            if(infile.hasNextLine())

            {

                myStack.push('\n');

            }

        }

        // Close the input file.

        infile.close();

        // Open the file in write mode.

        FileWriter output = new FileWriter("part1_output.txt");

        BufferedWriter outfile = new BufferedWriter(output);

        // Start the loop to traverse the stack.

        while(!myStack.isempty())

        {

            // Write the top character of the stack

            // in the file.

            outfile.write(myStack.top());

            // Remove the element from the stack.

            myStack.pop();

        }

        // Close the output file.

        outfile.close();

    }

    // Define a method to convert all the characters

    // of a file to uppercase using a queue.

    public static void part2() throws Exception

    {

        // Create a queue.

        Queue myQueue = new Queue();

        // Open the file in read mode.

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

        Scanner infile = new Scanner(input);

        // Start the loop to read the file.

        while(infile.hasNextLine())

        {

            // Store the line in a string.

            String line = infile.nextLine();

            // Start the loop to traverse the string.

            for(char ch: line.toCharArray())

            {

                // Insert the character in the queue.

                myQueue.enqueue(ch);

            }

            // Add a nextline character in the queue.

            if(infile.hasNextLine())

            {

                myQueue.enqueue('\n');

            }

        }

        // Close the input file.

        infile.close();

        // Open the file in write mode.

        FileWriter output = new FileWriter("part2_output.txt");

        BufferedWriter outfile = new BufferedWriter(output);

        // Start the loop to traverse the queue.

        while(!myQueue.isempty())

        {

            // Store the first element.

            char ch = myQueue.front();

            // If the current character is a letter,

            // convert it to uppercase and write it

            // in the file.

            if(Character.isLetter(ch))

            {

                outfile.write(Character.toUpperCase(ch));

            }

            // Otherwise, write the character in the file.

            else

            {

                outfile.write(ch);

            }

            // Remove the character from the queue.

            myQueue.dequeue();

        }

        // Close the output file.

        outfile.close();

    }

    // Define a method to compare the content of

    // 2 files using a queue.

    public static void part3() throws Exception

    {

        // Create 2 queues.

        Queue myQueue1 = new Queue();

        Queue myQueue2 = new Queue();

        // Open the file in read mode.

        File input = new File("part3_input1.txt");

        Scanner infile = new Scanner(input);

        // Start the loop to store the content

        // of the file in the first queue.

        while(infile.hasNextLine())

        {

            String line = infile.nextLine();

            for(char ch: line.toCharArray())

            {

                myQueue1.enqueue(ch);

            }

            if(infile.hasNextLine())

            {

                myQueue1.enqueue('\n');

            }

        }

        infile.close();

        // Open the second file in read mode.

        input = new File("part3_input2.txt");

        infile = new Scanner(input);

        // Start the loop to store the content

        // of the file in the second queue.

        while(infile.hasNextLine())

        {

            String line = infile.nextLine();

            for(char ch: line.toCharArray())

            {

                myQueue2.enqueue(ch);

            }

            if(infile.hasNextLine())

            {

                myQueue2.enqueue('\n');

            }

        }

        infile.close();

        // Start the loop to traverse both the queue.

        while(!myQueue1.isempty() || !myQueue2.isempty())

        {

            // Display the error message if the characters

            // does not match.

            if(myQueue1.front() != myQueue2.front())

            {

                System.out.println("The files are not the same.");

                return;

            }

            // Remove the character from both the queue.

            myQueue1.dequeue();

            myQueue2.dequeue();

        }

        // Display the result.

        System.out.println("The files are identical.");

    }

    // Define the main() method.

    public static void main(String[] args) throws Exception

    {

        // Call the methods to test.

        part1();

        part2();

        System.out.print("Result for part 3: ");

        part3();

    }

}

Sample input files:

input.txt:

This is a sample line.

12345

part3_input1.txt:

line 1

line 2

line 3

part3_input2.txt:

line 1

line 2

line 3