#include<stdio.h>
#include<stdlib.h>
#define max 50
typedef struct Queue {
int val[max];
int front, rear;
}
qu;
void enqueu(qu * , int);
int dequeu(qu * );
int peek(qu);
int isempty(qu);
int isfull(qu);
void disp(qu);
int main() {
int ch, v;
qu q;
q.front = q.rear = -1;
while (1) {
printf("\n1) Insert \n2) Delete \n3) Front value\n4) Display\n5) Exit");
printf("\n\nEnter the choice : ");
scanf("%d", &ch);
switch (ch) {
case 1:
if (!isfull(q)) {
printf("\n Enter the value : ");
scanf("%d", & v);
enqueu( & q, v);
} else
printf("\nNo more space");
break;
case 2:
if (!isempty(q)) {
v = dequeu( & q);
printf("\nThe deleted value from the front is %d", v);
} else
printf("\nNothing to delete");
break;
case 3:
if (!isempty(q)) {
printf("\nThe Value at the front is %d", peek(q));
} else
printf("\nNothing in the queue");
break;
case 4:
if (!isempty(q)) {
printf("\nValues are");
disp(q);
} else
printf("\nNothing in the queue");
break;
case 5:
exit(1);
default:
printf("\nNot in the menu");
}
}
}
void enqueu(qu * q, int f) {
int i;
if (q -> front == -1)
q -> front = q -> rear = 0;
else if (q -> rear == max - 1) {
for (i = q -> front; i <= q -> rear; i++)
q -> val[i - (q -> front)] = q -> val[i];
q -> rear = i - (q -> front);
q -> front = 0;
} else
q -> rear++;
q -> val[q -> rear] = f;
}
int dequeu(qu * q) {
int g;
g = q -> val[q -> front];
if (q -> front == q -> rear)
q -> front = q -> rear = -1;
else
q -> front++;
return g;
}
int peek(qu p) {
return p.val[p.front];
}
int isempty(qu p) {
if (p.front == -1)
return 1;
else
return 0;
}
int isfull(qu q) {
if (q.front == 0 && q.rear == max - 1)
return 1;
else
return 0;
}
void disp(qu q) {
int g;
g = q.front;
for (; g <= q.rear; g++)
printf("\n%d", q.val[g]);
}
