Beefy Boxes and Bandwidth Generously Provided by pair Networks
XP is just a number
 
PerlMonks  

comment on

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

Hi Laurent,

Thank you, for your caching algorithm. It has kept me busy after hours. I added Step 4 for less caching. Basically, commenting 2 lines.

I updated my posts here and here.

sub collatz_seq { my $input = shift; my $n = $input; my $result = 0; my $new_n; while ($n != 1) { $result += $cache[$n], last if defined $cache[$n]; $n % 2 ? ( $result += 2, $new_n = (3 * $n + 1) >> 1 ) : ( $result += 1, $new_n = $n >> 1 ); # $cache[$n] = $cache[$new_n] + ($n % 2 ? 2 : 1) # if defined $cache[$new_n] and $n < $max; $n = $new_n; } $cache[$input] = $result if $input < $max; return $result; }

A new member collatz3_e was added to the list.

# Intel i7 laptop, Docker Container, Ubuntu + Perlbrew Perl 5.30.1 collatz3_a.pl 1e7 32.291s (a) original, accepts argument collatz3_b.pl 1e7 30.134s (b) a + replaced division with >> 1 collatz3_c.pl 1e7 28.503s (c) b + removed 1 level of branching collatz3_d.pl 1e7 21.464s (d) c + reduced loop iterations collatz3_e.pl 1e7 19.357s (e) d + caching less # AMD 3970x, Docker Container, Ubuntu + Perlbrew Perl 5.30.1 collatz3_a.pl 1e7 13.130s (a) original, accepts argument collatz3_b.pl 1e7 12.394s (b) a + replaced division with >> 1 collatz3_c.pl 1e7 12.261s (c) b + removed 1 level of branching collatz3_d.pl 1e7 9.170s (d) c + reduced loop iterations collatz3_e.pl 1e7 7.681s (e) d + caching less

The 32-core machine reaches below 0.5 seconds for size 1e7. That includes the time to launch Perl, load modules, spin up and reap workers.

The Collatz Conjenture took over me. And finally am able to move on.

Kind regards, Mario


In reply to Re^4: Optimizing with Caching vs. Parallelizing (MCE::Map) by marioroy
in thread Optimizing with Caching vs. Parallelizing (MCE::Map) by 1nickt

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 drinking their drinks and smoking their pipes about the Monastery: (7)
    As of 2020-09-29 23:45 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      If at first I donít succeed, I Ö










      Results (154 votes). Check out past polls.

      Notices?