Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

If you can arrange your algorithm to be tail recursive, and use the magic form of goto, you can cut the memory growth to zero and achieve some very impressive figures.

8 seconds for 10 million recursions and 83 seconds for 100 million with the memory consumption never over 1.5 MB.

#!/usr/bin/perl -w use strict; $|++; my $count; deep( $ARGV[ 0 ] ); print $count; sub deep { ++$count and --$_[ 0 ] and goto \&deep; } __DATA__ [19:09:45.02] P:\test>422344 10000000 10000000 [19:09:53.02] P:\test> [19:10:03.21] P:\test>422344 100000000 100000000 [19:11:26.84] P:\test>

It takes a little effort to do, but when you need it it is worth it.


Examine what is said, not who speaks.
Silence betokens consent.
Love the truth but pardon error.

In reply to Re^5: Who's a thief? (No memory growth with magic goto) by BrowserUk
in thread Who's a thief? -- the follow up by Ovid

Title:
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?
    Username:
    Password:

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

    How do I use this? | Other CB clients
    Other Users?
    Others browsing the Monastery: (6)
    As of 2019-11-12 10:50 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      Strict and warnings: which comes first?



      Results (65 votes). Check out past polls.

      Notices?