A queue based on the linked list : Queue « Data Structure « C Tutorial

1. C Tutorial
2. Data Structure
3. Queue

# include <stdio.h>
# include <stdlib.h>
struct node
{
   int data;
   struct node *link;
};

void insert(struct node **front, struct node **rear, int value)
{
   struct node *temp;
   temp=(struct node *)malloc(sizeof(struct node));
   if(temp==NULL)
   {
      printf("No Memory available Error\n");
      exit(0);
   }
   temp->data = value;
   temp->link=NULL;
   if(*rear == NULL)
   {
      *rear = temp;
      *front = *rear;
   }
   else
   {
      (*rear)->link = temp;
      *rear = temp;
   }
}

void delete(struct node **front, struct node **rear, int *value)
{
   struct node *temp;
   if((*front == *rear) && (*rear == NULL))
   {
      printf(" The queue is empty cannot delete Error\n");
      exit(0);
   }
   *value = (*front)->data;
   temp = *front;
   *front = (*front)->link;
   if(*rear == temp)
   *rear = (*rear)->link;
   free(temp);
}

void main()
{
   struct node *front=NULL,*rear = NULL;
   int n,value;

   insert(&front,&rear,1);
   insert(&front,&rear,2);  
   insert(&front,&rear,3);
   insert(&front,&rear,4);

   delete(&front,&rear,&value);
   printf("The value deleted is %d\n",value);

   delete(&front,&rear,&value);
   printf("The value deleted is %d\n",value);

   delete(&front,&rear,&value);
   printf("The value deleted is %d\n",value);

}

The value deleted is 1
The value deleted is 2
The value deleted is 3