Services & ResourcesWolfram ForumsMathGroup Archive

[Date Index] [Thread Index] [Author Index]

Re: generating submultisets with repeated elements

• To: mathgroup at smc.vnet.net
• Subject: [mg103784] Re: [mg103681] generating submultisets with repeated elements
• From: David Bevan <david.bevan at pb.com>
• Date: Mon, 5 Oct 2009 13:58:10 -0400 (EDT)

Dan, Adriano, Kurt,

Thanks for the feedback.



Here are some performance results:



(* Dan *)

Length[multiSetsUpToK[Range[20],7]]//Timing

{18.14,888029}



(* Adriano *)

Length[coinSetsAdriano[Range[20],7]]//Timing

{9.516,888029}



(* Kurt *)

Length[coinSetsKurt[Range[20],7]]//Timing

Subsets::toomany: The number of subsets (189407486533) indicated by Subsets=
[{1,1,1,1,1,1,1,2,2,2,<<130>>},{1,7}] is too large; it must be a machine in=
teger.





And with my code:



Length[coinSets[Range[20],7]]//Timing

{5.063,888029}



My 'accumulator' approach seems to be quite effective!



However, I'm sure this can be improved significantly with the technique use=
d for KSubsets without too much difficulty.



David %^>

• Follow-Ups:
  • Re: Re: generating submultisets with repeated
    • From: David Bevan <david.bevan@pb.com>