On Mon, 20 Sep 2004, Richard Jones wrote:

> On Sun, Sep 19, 2004 at 11:02:44PM -0500, Brian Hurt wrote:
> > The code is actually fairly easy.  Take the length of the list.  Subtract
> > one for the root node.  The first (n-1)/2 elements are in the left hand
> > subtree, the last n-1-((n-1)/2) elements are in the right subtree.
>
> Wouldn't you have to iterate over the list when implementing this?
> What I mean to say is that this would work if you had a pre-sorted
> Array, but not a linked List.  ?

Did the question mention anything about the space used by the algorithm?
If one is allowed O(n) temp space, then simply converting the sorted
linked List into a temp array as the first step will keep the algorithm
O(n) (constant factors aside).  One would need a constant-time-access data
structure anyway, to build a balanced tree bottom-up in a functional way.
	Igor
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