Implementation of Queue ADT using java

Here's another /*ADT that we would like to implement and thats the queue.Here's a simple program for the implementation of a queue.


Program For Implementation Of Queue ADT


/*program for Queue implementation*/

import java.util.Scanner;
class Queue
{
/*array is used to hold queue elements*/
/*two integer variables are used for front and rear pointers*/
    int items[]=new int[10];
    int front,rear;

    Queue()
    {/*create queue*/
        front=0;
        rear=-1;
    }/*end createqueue*/

    void insert(int e)
    {/*if queue is not full insert new element at rear end of queue*/
        if(rear==9)
            System.out.println("Queue overflow");
        else
        {

            items[++rear]=e;
        }
    }/*end insert*/


    int empty()
    {/*Return 1 if queue is empty and 0 otherwise*/

        return(rear<front? 1:0);
    }/*end empty*/

    void remove()
    {/*if queue is not empty remove one element from front */
        if(empty()==1)
            System.out.println("Queue Underflow");
        else
            System.out.println("Removed element : "+items[front++]);
        /*end else*/
    }/*end rem*/

    void display()
    {/*Display all elements from front to rear end of queue*/
        if(empty()==0)
        {
            System.out.print("Queue : ");
            int t=front;
            while(t<=rear)
                System.out.print(" "+items[t++]);
            System.out.println();

        }
    }/*end display*/

}


class QSimple
{
public static void main(String args[])
{
    Scanner sc = new Scanner(System.in);
    Queue q=new Queue();
    int ch,n;
    while(true)
    {
        System.out.println("\n\tQUEUE");
        System.out.println("1.Insert");
        System.out.println("2.Remove");
        System.out.println("3.Exit");
        System.out.print("Enter your choice : ");
        ch=sc.nextInt();
        switch(ch)
        {
            case 1:System.out.print("Enter Number : ");
                   n=sc.nextInt();
                   q.insert(n);
                   q.display();
                   break;
            case 2:q.remove();
                   q.display();
                   break;
            case 3:return;
        }
    }


}/*end main*/
}

We will be further implementing more  such programs on our blog .Please Keep visiting and Suggest programs that you need.