Question

public class CharNode{

private CharNode link;

private char info;

public CharNode(char info)

{

this.info = info;

this.link = null;

}

public CharNode(char c, CharNode link)

{

this.info = info;

this.link = link;

}

public CharNode getLink() {

return link;

}

public void setLink(CharNode link) {

this.link = link;

}

public char getInfo() {

return info;

}

public void setInfo(char info) {

this.info = info;

}

}

//Remember Queue is a first-in-first-out data structure

public class CharQueue {

// front is an element that is put into queue the earliest.

CharNode front;

// the number of element in this queue should not exceed max_size

private int max_size;

public CharQueue(int max_size){

this.front = null;

this.max_size = max_size;

}

// Throws OverflowException if this queue is full;

// otherwise, adds element to the rear of this queue.

public void enqueue(char c){

/* 1. fill your code here */

/* 1. end your code */

}

// Throws UnderflowException if this queue is empty;

// otherwise, removes front element from this queue and returns it.

public char dequeue(){

/* 2. fill your code here */

/* 2. end of your code here */

}

// Returns true if this queue is empty; otherwise, returns false.

public boolean isEmpty(){

/* 3. fill your code here */

/* 3. end your code */

}

// Returns true if current size is equal to max_size; otherwise return false;

public boolean isFull(){

/* 4. fill your code here */

/* 4. end your code */

}

// Returns the number of elements in this queue.

public int size(){

/* 5. fill your code here */

/* 5. fill your code here */

}

// transfer the queue to a string and return it.

// if the queue is 'a', 'b', 'c' from the front to rear, the string will be "abc"

public String toString() {

String result = "";

CharNode pointer = this.front;

while(pointer != null) {

result += pointer.getInfo();

pointer = pointer.getLink();

}

return result;

}

}

PLEASE DO NOT INITIALIZE "REAR" OUTSIDE OF THE BLOCKS. ALSO, PLEASE DO NOT ADD ANY ATTRIBUTES TO THE CLASS.

Answer 1

ANSWER:-

CODE:-

import java.lang.*;
class CharNode{

   private CharNode link;

   private char info;

   public CharNode(char info)

   {

       this.info = info;

       this.link = null;

   }

   public CharNode(char c, CharNode link)

   {

       this.info = info;

       this.link = link;

   }

   public CharNode getLink() {

       return link;

   }

   public void setLink(CharNode link) {

       this.link = link;

   }

   public char getInfo() {

       return info;

   }

   public void setInfo(char info) {

       this.info = info;

   }

}

//Remember Queue is a first-in-first-out data structure

public class CharQueue {

   // front is an element that is put into queue the earliest.

   CharNode front;

   // the number of element in this queue should not exceed max_size

   private int max_size;

   public CharQueue(int max_size){

       this.front = null;

       this.max_size = max_size;

   }

   // Throws OverflowException if this queue is full;

   // otherwise, adds element to the rear of this queue.

   public void enqueue(char c){

   /* 1. fill your code here */

   /* 1. end your code */
       try{
           if (isFull()) {
               throw new Exception("Queue is full");
           }
           CharNode node = new CharNode(c);
           if(front == null){
               front = node;
               return ;
           }
          
           CharNode temp = front;
           while (temp.getLink()!=null) {
               temp = temp.getLink();
           }
           temp.setLink(node);
       }catch (Exception e) {
           System.out.println(e);
       }
   }

   // Throws UnderflowException if this queue is empty;

   // otherwise, removes front element from this queue and returns it.

   public char dequeue(){

   /* 2. fill your code here */

   /* 2. end of your code here */
       char ch = ' ';
       try{
           if(isEmpty())
               throw new Exception("Queue is empty");
           ch = front.getInfo();
           front = front.getLink();
       }catch (Exception e) {
           System.out.println(e);
       }
       return ch;
   }

   // Returns true if this queue is empty; otherwise, returns false.

   public boolean isEmpty(){

   /* 3. fill your code here */

   /* 3. end your code */
       return front == null;

   }

   // Returns true if current size is equal to max_size; otherwise return false;

   public boolean isFull(){

   /* 4. fill your code here */

   /* 4. end your code */
       return this.size() == this.max_size;
   }

   // Returns the number of elements in this queue.

   public int size(){
       int count = 0;
       CharNode temp = front;
       while (temp!=null) {
           count++;
           temp = temp.getLink();
       }
       return count;
   }

   // transfer the queue to a string and return it.

   // if the queue is 'a', 'b', 'c' from the front to rear, the string will be "abc"

   public String toString() {

       String result = "";

       CharNode pointer = this.front;

       while(pointer != null) {

           result += pointer.getInfo();

           pointer = pointer.getLink();

       }

       return result;

   }

   public static void main(String[] args) {
       CharQueue queue = new CharQueue(4);
       queue.enqueue('a');
       queue.enqueue('b');
       queue.enqueue('c');
       queue.enqueue('d');
       System.out.println(queue);
       System.out.println(queue.dequeue()+" is popped.");
       System.out.println("Now, queue is "+queue);
   }
}

NOTE:- If you need any modifications in the code,please comment below.Please give positive rating.THUMBS UP.

             THANK YOU!!!

OUTPUT:-