Queue implemented using Linked list in C.

queueImplementation.c

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

struct Node 
{
	int data;
	struct Node* next;
};

int count = 0;

struct Node* front = NULL;
struct Node* rear = NULL;
struct Node* temp;

void display()
{
	temp = front;
	if((front == NULL) && (rear) == NULL)
	{
		printf("\nQueue is Empty!");
		return;
	}
	printf("\nThere are currently %d items:-\n", count);
	while(temp != rear)
	{
		printf("%d ", temp->data);
		temp = temp->next;
	}
	if(temp == rear)
	{
		printf("%d", temp->data);
	}
	printf("\n");
}

void insert(int el)
{
	if(rear == NULL)
	{
		rear = (struct Node*)malloc(sizeof(struct Node));
		rear->next = NULL;
		rear->data = el;
		front = rear;
	}
	else
	{
		temp = (struct Node*)malloc(sizeof(struct Node));
		rear->next = temp;
		temp->data = el;
		temp->next = NULL;
		rear = temp;
	}
	count++;
	display();
}

void delete()
{
	temp = front;
	if(temp == NULL)
	{
		printf("\nQueue is Empty!\n");
		exit(1);
	}
	else
	{
		if(temp->next != NULL)
		{
			temp = temp->next;
			printf("\nElement removed is %d\n", front->data);
			free(front);
			front = temp;
		}
		else
		{
			printf("\nElement removed is %d\n", front->data);
			free(front);
			front = rear = NULL;
		}
	}
	count--;
	display();
}

int main()
{
	int choice, el;
	while(1)
	{
		printf("\n1.Insert\n2.Delete\n3.Display\nChoice: ");
		scanf("%d", &choice);
		switch(choice)
		{
			case 1:
				printf("\nElement to insert: ");
				scanf("%d", &el);
				insert(el);
				break;
			case 2:
				delete();
				break;
			case 3:
				display();
				break;	
			default:
				printf("\nInvalid Choice!");		
		}
	}		
	return 0;
}