public T GetKth(uint k)
{
if (k < 0 || k >= Size)
{
throw new IndexOutOfRangeException();
}
return(root.GetKth(k).value);
}
internal TreapNode GetKth(uint k)
{
uint pos = left != null ? left.size : 0;
int b = k.CompareTo(pos);
if (b == 0)
{
return(this);
}
if (b < 0)
{
return(left.GetKth(k));
}
else
{
return(right.GetKth(k - pos - 1));
}
}