In the simple queue we can insert the element only at the rear end and delete the element from the front end.
We are going to create a menu based program .In which we have three options one for insert element second for delete element and last for display elements of queue.
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#define max 5
int queue[max];
int rear,front;
rear=-1;
front=-1;
// function for insert element into queue
void insert()
{
int element;
if(rear==max-1)
printf("\nqueue is overflow");
else
{
if(front==-1)
front=0;
printf("\nEnter a value");
scanf("%d",&element);
rear+=1;
queue[rear]=element;
}
}
// function for delete element from the queue
void delete()
{
int element;
if(front==-1||front>rear)
printf("\nEnter underflow condition");
else
{
element=queue[front];
front+=1;
printf("%d is deleted\n",element);
}
}
// function for display all the element of the queue
void display()
{
int i;
if(front==-1|| front>rear)
printf("Underflow condition\n");
else
{
for(i=front;i<=rear;i++)
printf("%d\n",queue[i]);
}
}
// Driver function
void main()
{
int ch;
printf("1. insert element\n");
printf("2. delete element\n");
printf("3. display element\n");
printf("4. exit\n");
while(1)
{
printf("Enter your choice\n");
scanf("%d",&ch);
switch(ch)
{
case 1: insert();
break;
case 2: delete();
break;
case 3: display();
break;
case 4: exit(0);
default: printf("\nWrong key");
}
}
}
Output:-
1.insert element
2. delete element
3. display element
4. exit
Enter your choice
1
Enter a value 12
Enter your choice
2
12 is deleted
Enter your choice
1
Enter a value 23
Enter your choice
3
23
Enter your choice
4
