Circular Queue

import java.util.*;

public class CircularQueue

{

    int front,rear,size=5;

    int a[]=new int[size];

    CircularQueue()

    {

        front=rear=size-1;

    }

    void Insert(int n)

    {

        Ins:

        {

        if(rear==size-1)

            rear=0;

        else rear++;

        if(rear==front)

        {

            System.out.println("Overflow");

            break Ins;

        }

        a[rear]=n;

        }

    }

    void Remove()

    {

    if(front==size-1)

        front=0;

    else ++front;

    if(front==rear)

        System.out.println("Queue Empty");

    }

    void Display()

    {

        System.out.print("Back -> ");

        int n=front+1;

        if(n==size)

            n=0;

        while(n<=rear)

        {

            System.out.print(a[n++] + " -> ");

            if(n==size)

                n=0;

        }

        System.out.println("Front");

    }

    public static void main(String[] args)

    {

        CircularQueue a=new CircularQueue();

        Scanner in=new Scanner(System.in);

        int val,ch;

        while (true)

        {

            System.out.println("Enter your Choice");

            System.out.println("\n-------------------------------------");

            System.out.println("1 : Add\t2 : Del\t3 : Display\t4 : Exit");

            ch=in.nextInt();

            switch(ch)

            {

                case 1:

                {

                    System.out.println("Enter Value To Insert");

                    val=in.nextInt();

                    a.Insert(val);

                    break;

                }

                case 2:

                {

                    a.Remove();

                    break;

                }

                case 3:

                {

                    a.Display();

                    break;

                }

                case 4: System.exit(0);

                default: continue;

            }

        }

    }

}