I thought it was clear from the output (therefore I used ?. in the testcases) that the order of the input array should not be altered. That was the constraint you were missing.
R.E. Boss -----Original Message----- From: Programming <programming-boun...@forums.jsoftware.com> On Behalf Of Raul Miller Sent: donderdag 20 mei 2021 16:33 To: Programming forum <programm...@jsoftware.com> Subject: Re: [Jprogramming] ups & downs I could use some additional details. I mean... it seems to me that Foo=:<@/:~ would minimally satisfy the requirements which have been stated so far. But, presumably, there's some kind of "cost function" which we are trying to minimize, and presumably that has something to do with how pairs are handled? Or, perhaps, you have a constraint that no more than three of any given number may appear in any box, and I think I see a constraint that adjacent boxes must alternate their order. But perhaps there are also similar additional metrics or constraints? Thanks, -- Raul On Thu, May 20, 2021 at 6:43 AM R.E. Boss <r.e.b...@outlook.com> wrote: > > Given an array of numbers, like > > ?.@#~20 > 14 16 8 6 5 8 6 16 16 19 13 12 3 1 9 12 17 0 9 5 > > there is always a sequence of (non-strict) ups & downs, like > > 14 16;16 8 6 5;5 8;8 6;6 16 16 19;19 13 12 3 1; 1 9 12 17;17 0;0 > 9;9 5 > +-----+--------+---+---+----------+------------+---------+----+---+---+ > |14 16|16 8 6 5|5 8|8 6|6 16 16 19|19 13 12 3 1|1 9 12 17|17 0|0 9|9 > |5| > +-----+--------+---+---+----------+------------+---------+----+---+---+ > > Well, this is the way I prefer to have the ups & downs, where they share > their border terms. > Which verb makes this transformation? > Elegance, as always, is appreciated, correctness is a must, efficiency a > blessing. > > Some testcases: > > Foo ?.@#~25 > +----+---+---+-------+-----+-----+----+---+---+----+-------+----+----+-------+----+----+----+----+------+---+ > |19 6|6 8|8 6|6 10 23|23 16|16 21|21 1|1 9|9 8|8 22|22 13 1|1 14|14 > |2|2 17 20|20 9|9 15|15 7|7 22|22 4 2|2 9| > +----+---+---+-------+-----+-----+----+---+---+----+-------+----+----+-------+----+----+----+----+------+---+ > Foo ?.@#~30 > +--------+------+----+--------+--------+---------+----+-----+-----+----+----+-----+-----+----+-------+-------+-------+--------+-----+-----+ > |24 26 28|28 6 5|5 28|28 16 16|16 16 26|26 19 3 2|2 13|13 11|11 19|19 > |2|2 27|27 10|10 19|19 5|5 17 27|27 19 7|7 24 28|28 27 14|14 22|22 21| > +--------+------+----+--------+--------+---------+----+-----+-----+----+----+-----+-----+----+-------+-------+-------+--------+-----+-----+ > > > R.E. Boss > ---------------------------------------------------------------------- > 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
