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??

Here's one, naieve and probably inefficient, solution:

#!/usr/local/bin/perl -w use strict; my @strings=("~cake,pastry","pastry,~cake","cake,pastry"); foreach my $i ( 0..2 ) { for ( 0 .. 2) { next if ( $i == $_ ); my %left=map { $_ => 'nevermind' } split /,/,$strings[$i]; my %right=map { $_ => 'nevermind' } split /,/,$strings[$_]; for (keys( %left )) { delete $left{$_} if exists $right{$_}; } print "String $i matches $_!\n" unless ( keys %left || keys %right + ); } } __END__ Output: String 0 matches 1! String 1 matches 0!

Never mind the inefficient loop within loop within loop. The important bit to this method is splitting the strings into a hash, then walking over one hash and deleting the keys that exist in the other. If anything is left, the strings do not match.

One quick optimisation is to immediately stop and declare inequality when you find that a key in one hash does not exist in the other - that will save you iterating over the entire hash in the worst case.

Update: Check both hashes after delete step. See reply to this post from whatluo as to why. Note that the more efficient solution to this would be as whatluo suggests -- report inequality when the number of keys does not match between the two hashes before going into the delete loop. The solution I offer leaves the differing keys in the hashes, so you can do something with them.

CU
Robartes-


In reply to Re: string comparison by robartes
in thread string comparison by Madam

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? | Other CB clients
Other Users?
Others pondering the Monastery: (5)
As of 2023-01-28 07:39 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found

    Notices?