IMPLEMENTATION OF QUEUE USING C

SOURCE CODE:

#include<stdio.h>
#include<conio.h>
#define MAX 50
int queue_array[MAX];
int rear = - 1;
int front = - 1;
void main()
{
    int cho;
    clrscr();
    while (1)
    {
 printf("1.Insert element to queue \n");
 printf("2.Delete element from queue \n");
 printf("3.Display all elements of queue \n");
 printf("4.Quit \n");
 printf("Enter your choice : ");
 scanf("%d", &cho);
 switch (cho)
 {
     case 1:
     insert();
     break;
     case 2:
     delete();
     break;
     case 3:
     display();
     break;
     case 4:
     exit(1);
     default:
     printf("Wrong choice \n");
 }
    }
    getch();
}
insert()
{
    int add_item;
    if (rear == MAX - 1)
    printf("Queue Overflow \n");
    else
    {
 if (front == - 1)
 front = 0;
 printf("Inset the element in queue : ");
 scanf("%d", &add_item);
 rear = rear + 1;
 queue_array[rear] = add_item;
    }
}
delete()
{
    if (front == - 1 || front > rear)
    {
 printf("Queue Underflow \n");
 return ;
    }
    else
    {
 printf("Element deleted from queue is : %d\n", queue_array[front]);
 front = front + 1;
    }
}
display()
{
    int i;
    if (front == - 1)
 printf("Queue is empty \n");
    else
    {
 printf("Queue is : \n");
 for (i = front; i <= rear; i++)
     printf("%d ", queue_array[i]);
 printf("\n");
    }
}

                                OUTPUT