public TreapNode Remove(K key)
{
int b = key.CompareTo(this.key);
if (b == 0)
{
return((left == null) ? (right != null ? new TreapNode(right) : null) : left.Merge(right));
}
if (b < 0)
{
return(new TreapNode(this, left != null ? left.Remove(key) : null, right));
}
else
{
return(new TreapNode(this, left, right != null ? right.Remove(key) : null));
}
}