#include <stdio.h>
#define MAX 20
#include<stdlib.h>
int queue_array[MAX];
int rear = - 1;
int front = - 1;
void insert()
{
int add_item;
if (rear == MAX - 1)
printf("Queue Overflow \n");
else
{
if (front == - 1)
/*If queue is initially empty */
front = 0;
printf("\nEnter element : ");
scanf("%d", &add_item);
printf("\n%d is inserted in queue\n",add_item);
printf("------------------------------\n");
rear = rear + 1;
queue_array[rear] = add_item;
}
}
void delete()
{
if (front == - 1 || front > rear)
{
printf("Queue Underflow \n");
return ;
}
else
{
printf("\nElement deleted from queue is : %d\n", queue_array[front]);
printf("------------------------------\n");
front = front + 1;
}
}
void display()
{
int i;
if (front == - 1)
printf("Queue is empty \n");
else
{
printf("\nQueue is : ");
for (i = front; i <= rear; i++)
printf("%d ", queue_array[i]);
printf("\n------------------------------");
printf("\n");
}
}
int main()
{
printf("Perform operations on queue\n");
printf("------------------------------\n");
printf("\tMenu");
printf("\n------------------------------\n");
printf("1. Insert element \n");
printf("2. Delete element \n");
printf("3. Display queue\n");
printf("4. Exit\n");
printf("------------------------------\n");
int ch;
while (1)
{
printf("Choose operation : ");
scanf("%d", &ch);
switch(ch)
{
case 1:
insert();
break;
case 2:
delete();
break;
case 3:
display();
break;
case 4:
exit(1);
default:
printf("Invalid operation \n");
}
}
return 0;
}
