ep=:,~:/ NB. Build even parity op=:,[:-.~:/ NB. Build odd parity ep 1 1 1 ep 1 1 1 1 0 op 1 1 0 op 1 1 1 1 1 ep 0 0 0 op 0 0 1
On Tue, Oct 31, 2017 at 4:12 PM, Raul Miller <[email protected]> wrote: > I am not sure that if there's a better approach, though obviously we > could rephrase your approach slightly. > > For example: > > nextrow=: [ ~: 3 ~:/\ 0,],0: > grow=: , _2&{ nextrow {: > paritypattern=: 1 }. [ grow@:]^:([-1:) 0 ,: ] > > I hope this helps... > > -- > Raul > > > On Tue, Oct 31, 2017 at 5:05 PM, Ivan S <[email protected]> wrote: > > https://oeis.org/A118141 > > > > "A parity pattern is a matrix of 0's and 1's with the property that > every 0 is adjacent to an even number of 1's and every 1 is adjacent to an > odd number of 1's." > > > > As a J exercise, I've defined a verb that creates a parity pattern when > given its height and the first row. > > > > tripsums=: 3: +/\ (0&, @: ,&0) > > nextrow=: 2: | (+ tripsums) > > grow=: , _2&{ nextrow {: > > addzeros=: ,:~ ~:~ > > paritypattern=: ([: }. grow@:]^:(<: @: [)) addzeros > > 4 paritypattern 0 0 1 1 > > 0 0 1 1 > > 0 1 0 0 > > 1 1 0 1 > > 0 1 0 1 > > > > I would love to see other approaches to this problem. > > > > - Ivan > > ---------------------------------------------------------------------- > > 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
