Queue Operations using Single Linked List

Queue Operations using Single Linked List

#include<stdio.h>
#include<conio.h>
#include <stdlib.h>    

struct node
{
int data;
struct node *next;
};
struct node *front=NULL,*rear=NULL;

void insert()
{
int item;
struct node *temp,*tempe;

printf("\nEnter the Number : ");
scanf("%d",&item);
temp=(struct node *) malloc(sizeof(struct node));

temp->data=item;
temp->next=NULL;

if(rear==NULL)
{
front=temp;
rear=temp;
}
else
{
rear->next=temp;
rear=temp;
}
}



void del()
{


if(front==NULL)
printf("\Queue is Empty ");
else if(rear==front)
front=rear=NULL;
else
{
printf("%d is Deleted ",front->data);
front=front->next;
}
}

void display()
{
struct node *temp;

if(front==NULL && rear==NULL)
printf("\nQueue is Empty");
else
{
temp=front;
printf("\n Elements are : ");
while(temp->next!=NULL)
{
printf("%d\t",temp->data);
temp=temp->next;
}
printf("%d",temp->data);
}
}

void main()
{
int ch;
while(1)
{
printf("\n1.Insert\n2.Delete\n3.Display\n4.Exit");
printf("\nEnter your Choice : ");
scanf("%d",&ch);
switch(ch)
{
case 1:  insert();break;
case 2:  del();break;
case 3:  display();break;
case 4: exit(0);break;
            default: printf("\nYour Choice is Woring");
}
}

}