#define SIZE 5            /* Size of Circular Queue */
int CQ[SIZE],f=-1,r=-1;       /* Global declarations */

CQinsert(int elem)
{                       /* Function for Insert operation */
    if( CQfull()) printf("\n\n Overflow!!!!\n\n");
    else
    {
        if(f==-1)f=0;
        r=(r+1) % SIZE;
        CQ[r]=elem;
    }
}
int CQdelete()
{                      /* Function for Delete operation */
    int elem;
    if(CQempty()){ printf("\n\nUnderflow!!!!\n\n");
    return(-1); }
    else
    {
        elem=CQ[f];
        if(f==r){ f=-1; r=-1;} /* Q has only one element ? */
        else
            f=(f+1) % SIZE;
        return(elem);
    }
}
int  CQfull()
{                     /* Function to Check Circular Queue Full */
    if( (f==r+1) || (f == 0 && r== SIZE-1)) return 1;
    return 0;
}

int CQempty()
{                    /* Function to Check Circular Queue Empty */
    if(f== -1) return 1;
    return 0;
}

display()
{        /* Function to display status of Circular Queue */
    int i;
    if(CQempty()) printf(" \n Empty Queue\n");
    else
    {
        printf("Front[%d]->",f);
        for(i=f;i!=r;i=(i+1)%SIZE)
            printf("%d ",CQ[i]);
        printf("%d ",CQ[i]);
        printf("<-[%d]Rear",r);
    }
}

main()
{                         /* Main Program */
    int opn,elem;
    do
    {
        clrscr();
        printf("\n ### Circular Queue Operations ### \n\n");
        printf("\n Press 1-Insert, 2-Delete,3-Display,4-Exit\n");
        printf("\n Your option ? ");
        scanf("%d",&opn);
        switch(opn)
        {
        case 1: printf("\n\nRead the element to be Inserted ?");
            scanf("%d",&elem);
            CQinsert(elem); break;
        case 2: elem=CQdelete();
            if( elem != -1)
                printf("\n\nDeleted Element is %d \n",elem);
            break;
        case 3: printf("\n\nStatus of Circular Queue\n\n");
            display(); break;
        case 4: printf("\n\n Terminating \n\n"); break;
        default: printf("\n\nInvalid Option !!! Try Again !! \n\n");
            break;
        }
        printf("\n\n\n\n  Press a Key to Continue . . . ");
        getch();
    }while(opn != 4);
}

The post C Program for Circular QUEUE Operations – using Array first appeared on Student Projects.

#include
#define max 3
int q[10],front=0,rear=-1;
void main()
{
    int ch;
    void insert();
    void delet();
    void display();
    clrscr();
    printf("\nCircular Queue operations\n");
    printf("1.insert\n2.delete\n3.display\n4.exit\n");
    while(1)
    {
        printf("Enter your choice:");
        scanf("%d",&ch);
        switch(ch)
        {
        case 1: insert();
            break;
        case 2: delet();
            break;
        case 3:display();
            break;
        case 4:exit();
        default:printf("Invalid option\n");
        }
    }
}

void insert()
{
    int x;
    if((front==0&&rear==max-1)||(front>0&&rear==front-1))
        printf("Queue is overflow\n");
    else
    {
        printf("Enter element to be insert:");
        scanf("%d",&x);
        if(rear==max-1&&front>0)
        {
            rear=0;
            q[rear]=x;
        }
        else
        {
            if((front==0&&rear==-1)||(rear!=front-1))
                q[++rear]=x;
        }
    }
}
void  delet()
{
    int a;
    if((front==0)&&(rear==-1))
    {
        printf("Queue is underflow\n");
        getch();
        exit();
    }
    if(front==rear)
    {
        a=q[front];
        rear=-1;
        front=0;
    }
    else
        if(front==max-1)
        {
            a=q[front];
            front=0;
        }
        else a=q[front++];
        printf("Deleted element is:%d\n",a);
}

void display()
{
    int i,j;
    if(front==0&&rear==-1)
    {
        printf("Queue is underflow\n");
        getch();
        exit();
    }
    if(front>rear)
    {
        for(i=0;i<=rear;i++)
            printf("\t%d",q[i]);
        for(j=front;j<=max-1;j++)
            printf("\t%d",q[j]);
        printf("\nrear is at %d\n",q[rear]);
        printf("\nfront is at %d\n",q[front]);
    }
    else
    {
        for(i=front;i<=rear;i++)
        {
            printf("\t%d",q[i]);
        }
        printf("\nrear is at %d\n",q[rear]);
        printf("\nfront is at %d\n",q[front]);
    }
    printf("\n");
}
getch();

The post C program to implement Circular Queue operations first appeared on Student Projects.

#include
#include
#include
using namespace std;
class cqueue
{
   int q[5],front,rare;
   public:
      cqueue()
      {
	 front=-1;
	 rare=-1;
      }
      void push(int x)
      {
	 if(front ==-1 && rare == -1)
	 {
	   q[++rare]=x;
	   front=rare;
	   return;
	 }
	 else if(front == (rare+1)%5 )
	 {
	    cout <<" Circular Queue over flow";
	    return;
	 }
	 rare= (rare+1)%5;
	 q[rare]=x;
     }

     void pop()
     {
	if(front==-1 && rare==	-1)
	{
	  cout <<"under flow";
	  return;
	}
	else if( front== rare  )
	{
	  front=rare=-1;
	  return;
	}
	front= (front+1)%5;
     }
   



 void display()
    {
      int i;
      if( front <= rare)
      {
	for(i=front; i<=rare;i++)
	cout << q[i]<<" ";
      }
      else
      {
	 for(i=front;i<=4;i++)
	 {
	   cout <> ch;
switch(ch)
{
case 1: cout<<"enter element";
	cin >> ch;
	q1.push(ch); break;

case 2: q1.pop(); break;
case 3: q1.display(); break;
case 4: exit(0);
}
}
}

OUTPUT

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice1
enter element4

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice1
enter element5

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice1
enter element3

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice3
4 5 3

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice2

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice3
5 3

1.INSERT 2.DELETE 3.DISPLAY 4.EXIT
Enter ur choice4

The post C++ program to implement circular queue ADT using an array first appeared on Student Projects.