🚀 Programming Example
C Program of the circular queue
C Program of the circular queue
/*Program of circular queue*/
#include<stdio.h>
#include<stdlib.h>
#define MAX 10
int cqueue_arr[MAX];
int front=-1;
int rear=-1;
void display( );
void insert(item);
int del();
int peek();
int isEmpty();
int isFull();
main()
{
int choice,item;
while(1)
{
printf("1.Insert\n");
printf("2.Delete\n");
printf("3.Peek\n");
printf("4.Display\n");
printf("5.Quit\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1 :
printf("Input the element for insertion : ");
scanf("%d",&item);
insert(item);
break;
case 2 :
printf("Element deleted is : %d\n",del());
break;
case 3:
printf("Element at the front is : %d\n",peek());
break;
case 4:
display();
break;
case 5:
exit(1);
default:
printf("Wrong choice\n");
}/*End of switch*/
}/*End of while */
}/*End of main()*/
void insert(int item)
{
if( isFull() )
{
printf("Queue Overflow\n");
return;
}
if(front == -1 )
front=0;
if(rear==MAX-1)/*rear is at last position of queue*/
rear=0;
else
rear=rear+1;
cqueue_arr[rear]=item ;
}/*End of insert()*/
int del()
{
int item;
if( isEmpty() )
{
printf("Queue Underflow\n");
exit(1);
}
item=cqueue_arr[front];
if(front==rear) /* queue has only one element */
{
front=-1;
rear=-1;
}
else if(front==MAX-1)
front=0;
else
front=front+1;
return item;
}/*End of del() */
int isEmpty()
{
if(front==-1)
return 1;
else
return 0;
}/*End of isEmpty()*/
int isFull()
{
if((front==0 && rear==MAX-1) || (front==rear+1))
return 1;
else
return 0;
}/*End of isFull()*/
int peek()
{
if( isEmpty() )
{
printf("Queue Underflow\n");
exit(1);
}
return cqueue_arr[front];
}/*End of peek()*/
void display()
{
int i;
if(isEmpty())
{
printf("Queue is empty\n");
return;
}
printf("Queue elements :\n");
i=front;
if( front<=rear )
{
while(i<=rear)
printf("%d ",cqueue_arr[i++]);
}
else
{
while(i<=MAX-1)
printf("%d ",cqueue_arr[i++]);
i=0;
while(i<=rear)
printf("%d ",cqueue_arr[i++]);
}
printf("\n");
}/*End of display() */
1.Insert
2.Delete
3.Peek
4.Display
5.Quit
Enter your choice : 1
Input the element for insertion : 12
1.Insert
2.Delete
3.Peek
4.Display
5.Quit
Enter your choice : 3
Element at the front is : 12
1.Insert
2.Delete
3.Peek
4.Display
5.Quit
Enter your choice : 1
Input the element for insertion : 13
1.Insert
2.Delete
3.Peek
4.Display
5.Quit
Enter your choice : 4
Queue elements :
12 13
1.Insert
2.Delete
3.Peek
4.Display
5.Quit
Enter your choice : 5
Press any key to continue . . .
First understand the algorithm carefully. Then study the program line-by-line and compare it with the output. Finally, review the explanation section to strengthen your logic and programming understanding.
Rewrite the program without looking at the code. Modify values, conditions or logic and run it again. This helps improve confidence and strengthens coding skills much faster.