Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??

This is what the original poster did, but with different variable names and a slightly different regex, and it ran out of memory. But isn't this O(N2)? It seems to me that it greps every item in one array against all the items in the other array, so it's really no different from this:

my @array3; OUTER: for my $a1 (@array1){ for my $a2 (@array2){ next OUTER if they_match_somehow(); } push @array3, $a1; # it didn't match anything in @array2 }

Both cases have two nested loops; it's just harder to see them in the grep-within-a-grep method.

Aaron B.
Available for small or large Perl jobs; see my home node.


In reply to Re^4: Memory issue with large array comparison by aaron_baugher
in thread Memory issue with large array comparison by bholcomb86

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 meditating upon the Monastery: (6)
As of 2024-03-28 08:51 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found