Example Perfect2

Jan Burse, created Mar 08. 2019
/**
* Prolog code for the parallel search example.
*
* Perfect numbers were deemed to have important numerological
* properties by the ancients, and were extensively studied
* by the Greeks, including Euclid.
* http://mathworld.wolfram.com/PerfectNumber.html
*
* Warranty & Liability
* To the extent permitted by applicable law and unless explicitly
* otherwise agreed upon, XLOG Technologies GmbH makes no warranties
* regarding the provided information. XLOG Technologies GmbH assumes
* no liability that any problems might be solved with the information
* provided by XLOG Technologies GmbH.
*
* Rights & License
* All industrial property rights regarding the information - copyright
* and patent rights in particular - are the sole property of XLOG
* Technologies GmbH. If the company was not the originator of some
* excerpts, XLOG Technologies GmbH has at least obtained the right to
* reproduce, change and translate the information.
*
* Reproduction is restricted to the whole unaltered document. Reproduction
* of the information is only allowed for non-commercial uses. Selling,
* giving away or letting of the execution of the library is prohibited.
* The library can be distributed as part of your applications and libraries
* for execution provided this comment remains unchanged.
*
* Restrictions
* Only to be distributed with programs that add significant and primary
* functionality to the library. Not to be distributed with additional
* software intended to replace any components of the library.
*
* Trademarks
* Jekejeke is a registered trademark of XLOG Technologies GmbH.
*/
:- use_module(library(advanced/arith)).
:- use_module(library(advanced/aggregate)).
Y is X//2,
aggregate_all(sum(Z), ( between(1, Y, Z),
X rem Z =:= 0), X).
%%% single CPU
% ?- use_module(library(advanced/arith)).
% ?- time((between(1,20000,X), perfect2(X), fail; true)).
% % Up 10,940 ms, GC 74 ms, Thread Cpu 10,859 ms (Current 03/05/19 02:40:06)
% Yes
%%% multi CPU
% ?- use_module(library(runtime/distributed)).
% ?- time((balance((between(1,20000,X), perfect2(X))), fail; true)).
% % Up 6,372 ms, GC 47 ms, Thread Cpu 0 ms (Current 03/04/19 22:35:07)
% Yes

Comments