[Python-Dev] Priority queue (binary heap) python code

[David Abrahams]

Also, in case nobody has said so, worst-case performance for insertion into
a large heap (log N) is much better than for insertion into a sorted list
(N). Of course, in practice, it takes a really large heap to notice these
effects.

-Dave

From: "Martin v. Loewis" <martin@v.loewis.de>


> Oren Tirosh <oren-py-d@hishome.net> writes:
>
> > The only advantage of a heap is O(1) peek which doesn't seem so
> > critical.  It may also have somewhat better performance by a
> > constant factor because it uses an array rather than allocating node
> > structures.  But the internal order of a heap-based priority queue
> > is very non-intuitive and quite useless for other purposes while a
> > sorted list is, umm..., sorted!
>
> I think that heaps don't allocate additional memory is a valuable
> property, more valuable than the asymptotic complexity (which is also
> quite good). If you don't want to build priority queues, you can still
> use heaps to sort a list.
>
> IMO, heaps are so standard as an algorithm that they belong into the
> Python library, in some form. It is then the user's choice to use that
> algorithm or not.
>
> Regards,
> Martin