struct node
{
	int number;
	struct node * next;
	struct node * prev;
};

struct node *insert_node( struct node **head, int *value )
{
	struct node *new_node = NULL;
	struct node *cur_node = NULL;
	int found; /* 1 means found a place to insert the new node in, 0 means not*/
	new_node = (struct node *)malloc(sizeof(struct node));
	if(new_node == NULL)
	{
		printf("memory problem\n");
		exit(1);
	}
	new_node->number = *value;
/* If the first element */
	if (*head == NULL)
	{
		new_node->next = new_node->prev = new_node;
		*head = new_node;
	}
	else if (new_node->number < (*head)->number)
	{
		new_node->next = *head;
		new_node->prev = (*head)->prev;
		(*head)->prev = new_node;
		*head = new_node;
		(*head)->prev->next = *head;
	}
	else
	{
		cur_node = *head;
		found = 0;
		do
		{
			if( new_node->number < cur_node->number )
			{
				found = 1;
				break;
			}
			else
			{
//				last_node = cur_node;
				cur_node = cur_node->next;
			}
		}
		while ( cur_node != *head );
/* We got the right place to insert our node */
		if( found == 1 )
		{
			new_node->next = cur_node;
			new_node->prev = cur_node->prev;
			cur_node->prev->next = new_node;
			cur_node->prev = new_node;
		}
/* Insert at the tail of the list */
		else
		{
			new_node->next = *head;
			new_node->prev = (*head)->prev;
			(*head)->prev->next = new_node;
			(*head)->prev = new_node;
		}
	}
	return *head;
}