Queue Using Array

Program : Queue Using Array

import java.io.*; // importing input/output package

class queues // class definition

{
int data[]=new int[10]; // initializing array
int top,i=0;
int n=0,k=0; // initializing variables

queues() // constructor
{
top=-1;
n=10;
}

void create(int item) // create function
{
if (top>n) // conditional statement
{
System.out.print("OVERFLOW"); // print statement
return;
}
else
{
top=top+1; // incrementing top
data[top]=item;
}
}

void pop() // pop function

{

if (top==-1)
{
System.out.print("EMPTY"); // print statement
return;
}
else
{
data[k]=0;
k++;
}
}

void display() // display function

{
for(i=k;i<=top;i++) // looping structure

{
System.out.print("_\t"+data[i]+"\t_");
}
if (top==-1)
{
System.out.println("EMPTY");
}
}
}

class queue

{
public static void main(String args[]) throws IOException
// main function
{
int x,y,z,d,p;
DataInputStream a=new DataInputStream(System.in);
// invoking input class
queues t=new queues(); // object decleration
int exit=0;
while (exit==0)
{
System.out.println("\t\t\nMENU\n1.PUSH\n2.POP\n3.DISPLAY\n4.QUIT");
System.out.println("Enter your choice:");
x=Integer.parseInt(a.readLine()); // converting input received to integer
switch (x) // switching cases
{

case 1:

{
System.out.println("ENTER ELEMENT:");
p=Integer.parseInt(a.readLine());
t.create(p); // calling create function
}
break;


case 2:

{
y=0;
t.pop(); // calling pop function
}
break;

case 3:

{
t.display(); // calling display function
}
break;

case 4:

{
exit=1; // exit program
}
break;
}
}
}
}