Re: True or False ?

[Martin Trenkmann <martin.trenkmann@gmail.com>]

On 06/17/2012 12:35 PM, adacrypt wrote:
> On Sunday, June 17, 2012 10:37:17 AM UTC+1, Ludovic Brenta wrote:
>> Austin writes on comp.lang.ada:
>>> Do you know if these sort programs are used in real world programming
>>> today ?
>>
>> In our two-million-line mission-critical software we use heap sort and
>> tree sort but not quick sort.
>>
>> --
>> Ludovic Brenta.
>
> Many thanks.
>
> I have never heard of heap save - is this to be found in academic books?
> I'm taking it then that there has not been any huge advance in sorting methods over the past twenty years.
>
> Could I pick your brains a bit further.
>
> My scheme is ideal for accessing vast programs of millions of lines of source code like you mentioned - I tag every variable as it is being keyed in at the outset (at creation time) and then disable it until it is needed (I comment it out ) and if I do need it I simply uncomment it for sorting by a specially developed sorting method.  The tags can be stored up front or even stored in a file in memory for systematic calling by the main program
>
> Perhaps you would have a look at this new method later when I go public.
>
> Question - would it call it a big asset to improve on sorting methods? - given that there is so much computer power available to day - poor or even bad methods are getting by without notice?
>
> Many thanks for your help again.
>
> Regards - Austin.
>

Have you done an extensive research of sorting algorithms [1] before 
inventing your scheme or any comparison regarding best/avg/worst case 
runtime complexity?

I think there is still much research in this area going on and depending 
on the real use case many hybrid algorithms exist. For example the C++ 
std::sort from GCC uses intosort [2] which is a hybrid of quicksort and 
heapsort. Python and Java 7, as far as I know, use timsort [3], a hybrid 
of merge sort and insertion sort.

So I would be careful stating that "classroom" algorithms are not used 
in industry.

Anyway, the description of your scheme is not clear to me, but it 
reminds me a bit of counting sort [4], just to be sure not to reinvent 
the wheel.

Regards -- Martin Trenkmann

[1] http://en.wikipedia.org/wiki/Sorting_algorithm
[2] http://en.wikipedia.org/wiki/Introsort
[3] http://en.wikipedia.org/wiki/Timsort
[4] http://en.wikipedia.org/wiki/Counting_sort