Beefy Boxes and Bandwidth Generously Provided by pair Networks
No such thing as a small change
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
You're using numerical comparison (=) rather than string comparison (eq), and your loops aren't very Perlish. You don't describe your problem very clearly, but it looks like you want array2 to indicate values that follow corresponding values from array1: book follows read, apple follows eat, etc.

For the output, the first column should be things that don't appear in array2, and each subsequent column should be the values that follow the values in the previous column. If so, you want to reverse football and tennis in your example.

I found it made the most sense to work with hashes so I could model the "follows" relationship.

#!perl use strict; use warnings; my @array1 = qw(read eat book apple play football novel); my @array2 = qw(book apple novel banana football tennis magazine); # The follows relationship my %follow; @follow{@array1} = @array2; # Keeping track of what followers I have already used my %h2 = map {$_=>1} @array2; # Start with things that are not followers my @out = ([grep !exists $h2{$_}, @array1]); # Put followers of the previous column on as a new column while (%h2) { push @out, [@follow{@{$out[-1]}}]; delete @h2{@{$out[-1]}}; } use Data::Dumper; print Dumper(\@out); END { use Data::Dumper; print Dumper(\@out); }

Caution: Contents may have been coded under pressure.

In reply to Re: compare 2 arrays of strings and form a table by Roy Johnson
in thread compare 2 arrays of strings and form a table by sharan

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 contemplating the Monastery: (5)
As of 2024-03-29 15:48 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    No recent polls found