Implementing Circular Queue using Dynamic Memory Allocation

#include <stdio.h>

#include <stdlib.h>

#define MAX 5

struct Q

{

          int elements[MAX], front, rear;

};

void enq(struct Q *);

void display(struct Q *);

main()

{

int n,i;

struct Q *qptr=(struct Q *)malloc(sizeof(struct Q *));

qptr->front=-1;

qptr->rear=-1;

printf("enter the number of elements");

          scanf("%d",&n);

          for(i=1;i<=n;i++)

                    enq(qptr);

 display(qptr);

}

void enq(struct Q *qptr)

{

          int val;

 if((qptr->front == 0 && qptr->rear == MAX-1)||(qptr->front == qptr->rear+1))

          {

                   printf("Queue full");

                    return;

          }

          else if(qptr->front == -1 && qptr->rear == -1)

          {

                   qptr->front = 0;

                   qptr->rear=0;

 }

 else if(qptr->rear == MAX-1)

                   qptr->rear== 0;

 else

                   qptr->rear=qptr->rear+1;

printf("enter the data to be entered\n");

scanf("%d",&val);

qptr->elements[qptr->rear]=val;

}

void display(struct Q *qptr)

{

int i;

for(i=qptr->front;i<=qptr->rear;i++)

 printf("%d\t",qptr->elements[i]);

}

Output: