topN using a heap

[Andrei Alexandrescu via Digitalmars-d]

On 01/17/2016 03:32 PM, Ivan Kazmenko wrote:
> Here is a more verbose version.

OK, very nice. Thanks! I've modified topN to work as follows. In a loop:

* If nth <= r.length / log2(r.length)^^2 (or is similarly close to 
r.length), use topNHeap with one heap and stop
* If nth <= r.length / log2(r.length) (or is similarly close to 
r.length), use topNHeap with two heaps and stop
* Take a quickselect step, adjust r and nth, and continue

That seems to work nicely for all values involved.

All - let me know how things can be further improved. Thx!


Andrei