Beefy Boxes and Bandwidth Generously Provided by pair Networks
Come for the quick hacks, stay for the epiphanies.
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
If we're going for raw speed: don't use perl. :)

If I were doing this in assembly, and I wanted raw speed I'd:

  • Generate all of the possible combinations and their sorted values, like so: AA => AA, AB => AB, BA => AB, AC => AC, CA => AC.
  • Generate code (don't write it by hand!) that does something along the lines of pseudocode which works for aa, ab, ba, and bb:
    if (substr($base,0,1) eq 'a') { if (substr($base,1,1) eq 'a') { return 'aa'; } if (substr($base,1,1) eq 'b') { return 'ab' } } if (substr($base,0,1) eq 'b') { if (substr($base,1,1) eq 'a') { return 'ab' } if (substr($base,1,1) eq 'b') { return 'bb' } }
Which means that for any possible code of length n and an alphabet length q there's only n*q possible comparison/jumps to be made at worst case. (AGCA would be translated to AACG using only 7 comparisons and jumps total for example.)

I'm fairly confident that this would outperform any solution using a hash or a split/join/sort. At least, in assembler. I'm just a little too harried to write code to prove that it might be faster in Perl.


In reply to Re: Sorting characters within a string by clintp
in thread Sorting characters within a string by robsv

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



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others studying the Monastery: (8)
As of 2024-03-28 12:28 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found