Re: sorting large numbers of large records

["Matthew Heaney" <matthewjheaney@earthlink.net>]

"Brien L. Christesen" <blchrist@rac2.wam.umd.edu> wrote in message
news:bg3fgg$qig$1@grapevine.wam.umd.edu...
>
> Does anyone know of a good way to do this kind of sort?  Thanks in advance
> for any responses.

The list containers in the Charles library have a (quick)sort operation.
You could read the records into a singly-linked list container, and then
sort that.  Lists allow the sort to be done without copying elements, by
exchanging pointers.

Alternatively, you could use a vector or array, and then use the generic
sort algorithm (also part of the library) to sort that.  A vector is more
space efficient, but a sort requires copying of elements.

Another option is to read the records into a set, which automatically sorts
elements as they are inserted into the container.  (Sets and maps are
implemented using a balanced tree.)

A set is probably overkill, though, because you don't need do lookups or
anything.  If all you want to do is sort, then try using a list.

The Charles library is available from my website.

http://home.earthlink.net/~matthewjheaney/charles/

Look for a new release of Charles in the next few days.  I am currently
synchronizing the interfaces of the hashed vs. sorted associative
containers.

Send me email if you have any specific library questions.

-Matt