Beefy Boxes and Bandwidth Generously Provided by pair Networks
P is for Practical

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
I am trying to improve my solution to this problem by incorporating the shortcuts I outlined here. This requires ordering the powerset of prime factors in some sort of progressive order:
input = 2, 3, 5, 7 output: 2 2 3 2 3 5 2 3 5 7 ------- 2 3 7 ------- 2 5 2 5 7 ------- 2 7 ------- 3 3 5 3 5 7 ------- 3 7 ------- 5 5 7 ------- 7 -------

In this simple example, the number is 210 so any factor larger than 14 need not be considered. This means that after checking 2*3*5, we can skip 2*3*5*7 and after we check 3*5, we can skip 3*5*7.

Additional savings can be found if the primes repeat since it will lead to duplicate subsets. Prior to determining the product of the subset, we can easily determine if we have already seen this subset and skip. If this previously seen subset was also too large, we can skip the entire progression.

Anyone have any ideas about how to implement this?

Cheers - L~R

Update: You can see the result of this exercise here

In reply to Generating powerset with progressive ordering by Limbic~Region

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others drinking their drinks and smoking their pipes about the Monastery: (4)
    As of 2018-06-20 02:09 GMT
    Find Nodes?
      Voting Booth?
      Should cpanminus be part of the standard Perl release?

      Results (116 votes). Check out past polls.