While your approach is certainly achieving your objective of helping you learn the ins and outs of J, it doesn't seem to be the simplest or quickest way to solve the PE13 problem.
Maybe worthwhile taking a step back? On Mon, May 22, 2017 at 9:50 PM, Lafras Uys <[email protected]> wrote: > Hi, > > I am working through Project Euler to learn J. For PE 13 I am trying to > implement a carry function. For example: > > 41 carry 35 = 39 NB. Add the tens from 41 to the ones of 35 > > This is what I have so far: > > NB. "Large" numbers > > ] T=: 6 6 $ 3 7 1 0 7 9 4 6 3 7 6 9 7 4 3 2 4 9 9 1 9 4 2 2 2 3 0 6 7 5 > 8 9 2 6 9 7 > > 3 7 1 0 7 9 > > 4 6 3 7 6 9 > > 7 4 3 2 4 9 > > 9 1 9 4 2 2 > > 2 3 0 6 7 5 > > 8 9 2 6 9 7 > > < \ S=: +/ |. "1 T NB. Suffixes of the reversed radix sums > > +--+-----+--------+-----------+--------------+-----------------+ > > |41|41 35|41 35 25|41 35 25 18|41 35 25 18 30|41 35 25 18 30 33| > > +--+-----+--------+-----------+--------------+-----------------+ > > f=: (0&{ @: ((0 10) & #:)) @: [ NB. Grab the number of tens in x > > g=: + > > h=: ] > > carry=: (f g h) > > carry/ L:0 < \ S > > +--+--+--+--+--+--+ > > |41|39|32|27|40|46| > > +--+--+--+--+--+--+ > > > My carry verb works fine for the first two numbers, however as soon as > there are three or more numbers it looks like all the "tens" from x is > added to y, e.g. 4+3+25 = 32 instead of 28. My understanding is that `/` > acts like a fold, maintaining an accumulator as in +/ 2 3 4 5 = (((2+3) + > 4) + 5) so that the left hand side is the result of the computation to > date. I'm clearly missing something important here. > > > Any comments and help is appreciated, > > > Lafras > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
