Yes that's more direct. The difference in time and space is less than I would have expected for "shortish" lists. (<10000) items.
On Mon, Jun 29, 2015 at 4:07 PM, Marshall Lochbaum <[email protected]> wrote: > Note that (#~/@:|:) is a much faster inverse. > > Marshall > > On Mon, Jun 29, 2015 at 04:22:08PM +0000, 'Pascal Jasmin' via Programming > wrote: > > pretty much the same as the rosettacode solution, but focused on an > internal representation rather than outputting a string > > > > torle =: (1 ,~ 2&(~:/\)) ({. , #);.2 ] > > frle =: ([: ; <@#~/"1) :.torle > > > > > > > > ----- Original Message ----- > > From: Raul Miller <[email protected]> > > To: Programming forum <[email protected]> > > Cc: > > Sent: Monday, June 29, 2015 12:04 PM > > Subject: Re: [Jprogramming] integer run length compression > > > > Perhaps http://rosettacode.org/wiki/Run-length_encoding#J > > > > Thanks, > > > > -- > > Raul > > > > > > On Mon, Jun 29, 2015 at 11:55 AM, John Baker <[email protected]> > wrote: > > > I vaguely remember reading forum traffic sometime ago about a simple > > > J based run length encoding verb for integers. > > > > > > eg: > > > > > > If you have list of integers with many runs of the same value. > > > > > > 0 0 0 0 0 0 2 4 4 4 4 2 0 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 > 2 0 2 > > > 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 > > > > > > What's a good way to compress, and decompress, this using only J? > > > > > > Just thought I would ask before rolling my own. > > > > > > -- > > > John D. Baker > > > [email protected] > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- John D. Baker [email protected] ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
