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Re: QuickFactorInteger

  • To: mathgroup at smc.vnet.net
  • Subject: [mg93857] Re: [mg93831] QuickFactorInteger
  • From: DrMajorBob <btreat1 at austin.rr.com>
  • Date: Thu, 27 Nov 2008 05:30:51 -0500 (EST)
  • References: <gfgqib$dm1$1@smc.vnet.net> <gfh3ca$g1d$1@smc.vnet.net>
  • Reply-to: drmajorbob at longhorns.com

Yeah, <sarcasm on>, this is an easy problem; WRI chose a slow algorithm on  
purpose! <sarcasm off>

Seriously, all you must do to become astonishingly famous is JUST to solve  
this problem.

The difficulty of it is the basis of most crytographic encodings, today.

Here's a MUCH smaller problem, just to illustrate:

Times @@ Rest@NestList[NextPrime, 11^25, 2]
Timing@FactorInteger@%

11739085287969531650666654799694684820316871906575301

{13.2398, {{108347059433883722041830257,
    1}, {108347059433883722041830293, 1}}}

Two 27 digit primes.

Bobby

On Wed, 26 Nov 2008 06:22:31 -0600, Artur <grafix at csl.pl> wrote:

> Dear Mathematica Gurus,
>
> Who know how construct procedure to obtained reasonable primes divisors
> of big number in reasonable time. If number have two big primes divisors
> range 40 decimal digits Mathematica function FactorInteger working hours
> and do nothing. I want do time limit (e.g. 5 second) and received list
> of factors which was obtained after these 5 seconds or do other  trick
> to obtained partialy result of FactorInteger.
>
> Best wishes
> Artur
>



-- 
DrMajorBob at longhorns.com


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