#include<stdio.h>
#define MAX 4
int queue_array[MAX];
int rear=-1;
int front=-1;
int main()
{
    int choice;
    while (1)
    {
        printf("1.Insert element to queue \n");
        printf("2.delete element to queue \n");
        printf("3.display element to queue \n");
        printf("4.Exit\n");
        printf("Enter your choice :\n");
        scanf("%d",&choice);
        switch(choice)
        {
        case 1:
            insert();
            break;
        case 2:
            delete();
            break;
        case 3:
            display();
            break;
        case 4:
            exit(1);
        default :
            printf("Wrong choice \n");
        }
    }
}
insert()
{
    int item;
    if(rear==MAX-1)
        printf("queue overflow\n");
    else
    {

        if (front==-1)
            front=0;
        printf("Insert the element in queue:\n");
        scanf("%d",&item);
        rear=rear+1;
        queue_array[rear]=item;
    }
}
delete()
{
    if(front==-1||front > rear)
    {
        printf("queue underflow\n");
        return;
    }
    else
    {
        printf("Element delete from queue is :%d\n",queue_array[front]);
    }
}
display()
{
    int i;
    if(front==-1)
        printf("queue is empty\n");
    else
    {
        printf("queue is:\n");
        for(i=front; i<=rear; i++)
            printf("%d\n",queue_array[i]);
        printf("\n");
    }
}