Beefy Boxes and Bandwidth Generously Provided by pair Networks
Don't ask to ask, just ask
 
PerlMonks  

comment on

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

Hi again,

I would like to seek your help in optimizing a double loop which is in the heart of my program. I really need it to be as efficient as possible to cut on running times, since it is called many times.

The idea is this. I have a large array @arr of size up to 10^6. I then get "ranges" in this array e.g. {FROM=>25000 TO=>40000} and I need to ++ all the cells in the range. What I do now is something like:

my @arr= (0) x $length; while ( ... get range to process ...) { for (my $i=$range->{FROM}; $i<$range->{TO}; ++i) { $arr[$i]++; } }

Is there anything I can do to optimize this process? Assume "get range to process" is already optimized.

Thanks!


In reply to Optimizing a double loop by roibrodo

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 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? | Other CB clients
Other Users?
Others cooling their heels in the Monastery: (3)
As of 2021-10-25 05:27 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    My first memorable Perl project was:







    Results (89 votes). Check out past polls.

    Notices?