Program in C to implement Queue operation (insert, delete, travers) using linear array

#include<stdio.h>
#include<conio.h>
int que[5];
int front=-1,rear=-1;
void insert(int);
int del();
void disp();
void main()
{
int ch,item;
clrscr();
while(1)
{
printf("\n\n1....Insert\n2....Delete\n3.....Display\n4....Exit");
printf("\nEnter Ur Choice: ");
scanf("%d",&ch);
switch(ch)
{
case 1:
printf("\nEnter Item:");
scanf("%d",&item);
insert(item);
break;
case 2:
item=del();
if(item!=-1)
printf("\nItem deleted= %d",item);
break;
case 3:
disp();
break;
case 4:
printf("\program terminating...\nPress any key to continue...");
exit(0);
default:
printf("\nEnter correct choice");
}
}}
void insert(int item)
{
if (rear==4)
{
printf("\nQueue overflow");
return ;
}
if (front==-1)
{
front=0;
rear=0;
}
else
{
rear=rear+1;
}
que[rear]=item;
}
int del()
{
int item;
if(front==-1)
{
printf("\nQueue Underflow");
return (-1);
}
item=que[front];
if(front==rear)
{
front=-1;
rear=-1;
}
else
front++;
return (item);
}
void disp()
{
int i;
if(front==-1)
{
printf("\nQueue Underflow");
return ;
}
printf("\nQueue is:");
for(i=front;i<=rear;i++)
printf("\n%d",que[i]);
}

 
Output: