On Mon, Aug 24, 2009 at 3:50 AM, Bo Jacoby<[email protected]> wrote: > Impressive. But, as often with J, not immediately comprehensible. ... >> Fra: Roger Hui <[email protected]> >> j #~ (j e. <:p: j) * (j e. >:*:j) * (2...@q: j) * 2...@q:@(|.&.":"0) j=: >> 1+i.1e6 >> 226 47962 95482 103042 140626 194482 370882
j=: 1+i.1e6 numbers one through one million |.&.":"0 those numbers with their digits reversed 2 = #...@q: 1 if they are the product of 2 primes, 0 if not [note that Roger's code requires that both the number and the reversed digits number be the product of 2 primes.] (j e. >:*:j) 1 if they are one plus a square number, 0 if not (j e. <:p: j) 1 if they are one less than than a prime. Roger's code looks for numbers which have all of these qualities. And... I find I can not comprehend the english I wrote any faster than I could comprehend his original code. -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
