Hi David, This seems to need BINARY_DATA Linda
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of David Lambert Sent: Thursday, March 06, 2014 9:27 AM To: programming Subject: Re: [Jprogramming] a good bar bet! NB. In c I'd use an algorithm such as BS =: 8 NB. block size BLOCK =: 2^BS NB. convert to blocks with padding BLOCKED_DATA =: BS (#.\~ -)~ BINARY_DATA count_bits =: +/"1@:#: assert 0 1 5-:count_bits 2b0 2b1000 2b110010010100 NB. crucial idea, use known time for bit counting COUNTS =: ([: count_bits i.) BLOCK HIGHS =: BLOCKED_DATA ([: +/ {) COUNTS NB. Maybe we're just looking for HIGHS =: +/BINARY_DATA LOWS =: (HIGHS -~ #) BINARY_DATA SORTED_BINARY_DATA =: (LOWS , HIGHS) # 0 1 On 03/06/2014 07:00 AM, [email protected] wrote: > Date: Wed, 5 Mar 2014 20:52:35 -0800 > From: Roger Hui<[email protected]> > To: Programming forum<[email protected]> > Subject: Re: [Jprogramming] a good bar bet! > Message-ID: > <camz_i_byhhgpqkvmbufbfx3g9292sc2xvhzkqjcovhhwbdi...@mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > How about an extreme version of the sort problem. Suppose x is a vector of > bits (such as they have in APL). How do you sort x? > > This would have been one way to solve the sorting small integers problem: > figure out how to sort 0-1 vectors and then work your way up from that. I > once posed the 88 Hats > Problem<http://www.jsoftware.com/jwiki/Essays/88_Hats>to a very smart > and very persistent intern. He solved it by generalizing a > solution to the 2 Hats problem. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
