#include<stdio.h>
#include<stdlib.h>
#define max 5
typedef struct Queue {
int val[max];
int rear, front;
}
qu;
void enque(qu * , int);
int deque(qu * );
int peek(qu);
int isempty(qu);
int isfull(qu);
void disp(qu);
void main() {
qu q;
int g, v;
q.rear = q.front = -1;
while (1) {
printf("\n1) Insert\n2) Delete\n3) Peek\n4) Display\n5) Exit");
printf("\n Enter your choice :");
scanf("%d", & g);
switch (g) {
case 1:
printf("\n Enter the value");
scanf("%d", & v);
if (!isfull(q))
enque( & q, v);
else
printf("\nNo more space");
break;
case 2:
if (!isempty(q))
printf("\nDeleted element is %d", deque( & q));
else
printf("\nNothing to delete");
break;
case 3:
if (!isempty(q))
printf("\n value at front %d", peek(q));
else
printf("\n Nothing in the front");
break;
case 4:
if (!isempty(q)) {
printf("\nValues int queue : ");
disp(q);
} else
printf("\nNothing to display");
break;
case 5:
exit(0);
default:
printf("\n wrong choice");
}
}
}
void enque(qu * q, int p) {
if (q -> rear == -1)
q -> rear = q -> front = 0;
else if (q -> rear == max - 1)
q -> rear = 0;
else
q -> rear++;
q -> val[q -> rear] = p;
}
int deque(qu * q) {
int g;
g = q -> val[q -> front];
if (q -> front == q -> rear)
q -> rear = q -> front = -1;
else if (q -> front == max - 1)
q -> front = 0;
else
q -> front++;
return g;
}
int peek(qu q) {
return q.val[q.front];
}
int isempty(qu q) {
if ((q.front == -1 && q.rear == -1))
return 1;
else
return 0;
}
int isfull(qu q) {
if ((q.front == 0 && q.rear == max - 1) || q.front == q.rear + 1)
return 1;
else
return 0;
}
void disp(qu q) {
int i;
if (q.front > q.rear) {
for (i = q.front; i <= max - 1; i++)
printf("%d,", q.val[i]);
for (i = 0; i <= q.rear; i++)
printf("%d,", q.val[i]);
} else
for (i = q.front; i <= q.rear; i++)
printf("%d,", q.val[i]);
}
