Well... the simplest J implementation for that problem would be: 462 462
But there are other ways of getting that result: +/(* 0 = 2&|)1+i.42 462 +/(* 0 = 2&|)i.43 462 +/2*i.>:-:42 462 +/2*1+i.21 462 +/2*i.22 462 and... so on... I suppose a part of the question is: what is acceptable, to the audience, to do outside the computer implementation? (Which, in turn, can lead to forbidding all languages except the one preferred by a specific person, among other things.) Thanks, -- Raul On Mon, Aug 28, 2017 at 1:02 PM, Skip Cave <[email protected]> wrote: > A simple problem posted on Quora: > > What is the sum of all the even numbers from 2 to 42? > > My J solution: > a=:>:i.42 > +/(-.2|a)#a > 462 > > I'm sure this can be done in a single line using a hook or fork. > but I'm not clear enough with the train rules to put this all together > on a single line. > Any suggestions? > > > > > > Skip Cave > Cave Consulting LLC > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
