// Suppose t != null.
TreapNode <T> RemoveTarget(TreapNode <T> t, T item)
{
if (t.TypedLeft == null && t.TypedRight == null)
{
--Count;
return(null);
}
if (t.TypedRight == null)
{
return(t.TypedLeft);
}
if (t.TypedLeft == null)
{
return(t.TypedRight);
}
if (t.TypedLeft.Priority > t.TypedRight.Priority)
{
t = t.RotateToRight() as TreapNode <T>;
}
else
{
t = t.RotateToLeft() as TreapNode <T>;
}
return(Remove(t, item));
}
TreapNode <T> Add(TreapNode <T> node, T item, int priority)
{
if (node == null)
{
++Count;
return(new TreapNode <T> {
Key = item, Priority = priority
});
}
var d = compare(item, node.Key);
if (d == 0)
{
return(node);
}
if (d < 0)
{
node.TypedLeft = Add(node.TypedLeft, item, priority);
if (node.Priority < node.TypedLeft.Priority)
{
node = node.RotateToRight() as TreapNode <T>;
}
}
else
{
node.TypedRight = Add(node.TypedRight, item, priority);
if (node.Priority < node.TypedRight.Priority)
{
node = node.RotateToLeft() as TreapNode <T>;
}
}
return(node);
}