public void delete_rear(out double d)
{
if (rear == null)
throw new InvalidOperationException("no elements to remove");
d = rear.value;
rear = rear.next;
if (rear != null)
rear.prev = null;
else
front = null;
}
public void delete_front(out double d)
{
if (front == null)
throw new InvalidOperationException("no elements to remove");
d = front.value;
front = front.prev;
if (front != null)
front.next = null;
else
rear = null;
}
public void add_front(double p)
{
double_node newfront = new double_node(p);
if (front == null && rear == null)
rear = front = newfront;
else
{
front.next = newfront;
newfront.prev = front;
front = newfront;
}
}
public void add_rear(double p)
{
double_node newrear = new double_node(p);
if (front == null && rear == null)
rear = front = newrear;
else
{
rear.prev = newrear;
newrear.next = rear;
rear = newrear;
}
}
public double_dutor(double p)
{
rear = front = new double_node(p);
}
