Write a C program to implement the concept of CIRCULAR QUEUE

PROGRAM:-

#include<stdio.h>
#define MAX 5
int f=-1,r=-1,cq[MAX];
void ins(); void delt(); void dis();

//this program is developed by thezenithcoder.blogspot.com

void main()
{ int cho=123;
  while(cho<4||cho==123)
  {printf("1.INSERT\n2.DELETE\n3.DISPLAY\n4.EXIT\n");
   printf("Enter your choice:");
   scanf("%d",&cho);
   switch(cho)
   {case 1: ins(); printf("\n"); break;
    case 2: delt(); printf("\n"); break;
case 3: dis(); printf("\n"); break;
default:printf("\nThank You.\nHave a Nice day.\n");
   }
  }

}

//this program is developed by thezenithcoder.blogspot.com

void ins()
{ if((f==0 && r==MAX-1)||(f==r+1)) printf("Circuler Queue is full.\n");
  else{ if(f==-1){ f=0; } else if(r==MAX-1){ r=-1; }
        printf("Enter your item to insert:");
r++; scanf("%d",&cq[r]);  } 
}

//this program is developed by thezenithcoder.blogspot.com

void delt()
{ int item;
  if(f==-1) printf("Circuler Queue is empty.\n");
  else{ if(f==r){ r=0; f=0; } else if(f==MAX-1){ f=0; }
        item=cq[f]; printf("%d is deleted.\n",item); f++;}
}

//this program is developed by thezenithcoder.blogspot.com

void dis()
{ int i;
  if(f==-1) printf("Circuler Queue is empty.\n");
  else{ if(f<=r) { for(i=0;i<MAX;i++){ if(i>=f && i<=r) printf(" %d ",cq[i]);
                                       else printf(" __ "); } }
        else{ for(i=0;i<=r;i++) printf(" %d ",cq[i]);
              for(i=r+1;i<f;i++) printf(" __ ");
      for(i=f;i<MAX;i++) printf(" %d ",cq[i]); }
      }
  printf("\n");

}

OUTPUT:-

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:1

Enter your item to insert:1

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:1

Enter your item to insert:3

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:1

Enter your item to insert:5

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:1

Enter your item to insert:7

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:1

Enter your item to insert:9

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:3

 1  3  5  7  9

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:2

1 is deleted.

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:2

3 is deleted.

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:3

 __  __  5  7  9

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:1

Enter your item to insert:2

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:3

 2  __  5  7  9

1.INSERT

2.DELETE

3.DISPLAY

4.EXIT

Enter your choice:4

Thank You.

Have a Nice Day.