Question

A Queue is a linear data structure in which the operations are performed based on FIFO (First In First Out).

Define a class Queue with the following details:

Class name	Queue
Data member/instance variable:
dat[ ]	array to hold the integer elements
cap	stores the maximum capacity of the queue
front	to point the index of the front
rear	to point the index of the rear
Member functions/methods:
Queue(int max)	constructor to initialize the data member cap = max, front = rear = 0 and create the integer array
void add_dat(int v)	to add integers from the rear index if possible else display the message(“Queue full”)
int pop_dat( )	to remove and return elements from front, if any, else returns -999
void display()	to display elements of the queue

Specify the class Queue giving the details of void add_dat(int) and int pop_dat( ). Assume that the other functions have been defined.

The main( ) function and algorithm need NOT be written.

Answer 1

import java.util.*;
class Queue
{
int dat[];
int cap, front, rear;
public Queue( int max)
{
cap=max;
dat = new int[ cap];
front=rear=0;
}
public void add_dat(int v)
{
if(rear=cap-1)
{
System.out.println("Queue full");
return;
}
dat[rear++]=v;
}
public int pop_dat()
{
if(front=rear)
{
System.out.println("Queue empty");
retum -999;
}
else
return dat[front++];
}
public void display()
{
for(int i=front; i<rear; i++)
{
System.out.print(dat[i]+" ");
}
}
}