in reply to comparing the elements of an array

I wasn't quite sure if these ABC's can be numbers of if you just have single text letters. If they are single text letters as your test data shows, then I would keep them as strings and use tr to count the number of matches. An eval is needed on tr because the pattern is a run time variable. The below demonstrates this general technique.

There can be all kind of "yeah but's" and "what if's" when intersecting things. I just took the approach of solving the problem with your test data. If the data is actually more complex than shown, then that changes things. 

#!/usr/bin/perl
use warnings;
use Data::Dumper;

my @data=(
"A B C D E F G", "B F G", "D E F",
"A C", "A D E F G", "G",);

my $standard = shift(@data);
print "standard line: 1 => $standard\n";
$standard =~ s/\s+//g;

my %results;
my $original;
my $line_num=2;

foreach  (@data)
{
   $original{$_}=$line_num++;
   $results{$_}= eval "tr/$standard//";
   die @$ if $@;
}

my @sorted_keys = sort {$results{$b} <=> $results{$a} 
                                     or                
                        $original{$a} <=> $original{$b}
                        }keys %results;
foreach (@sorted_keys)
{
   print "line: $original{$_}  => $_  \t: matches $results{$_}\n";
}

__END__
standard line: 1 => A B C D E F G
line: 5  => A D E F G      : matches 5
line: 2  => B F G      : matches 3
line: 3  => D E F      : matches 3
line: 4  => A C      : matches 2
line: 6  => G      : matches 1

[download]

Replies are listed 'Best First'.
Re^2: comparing the elements of an array
by young_perl_learner22 (Initiate) on Mar 25, 2010 at 19:32 UTC

    Hi,

    Thanks for your help. But, I thought, I was not clear

    in asking my question; sorry for that. I have arrays

    of arrays and I want to compare each of the elements

    of one array with the elements of the other array.

    For example:

    @data = (["A", "B", "C", "D", "E", "F", "G"],      ["A","C"],     ["B","F","G"],    ["A","D","E","F","G"], ["D","E","F"], ["G"], ["M", "N", "O"], ["O"], ["M", "N"], ; for $row ( 0 .. $#data ) { for $column ( 0 .. $#{$data[$row]} ) { print "$row $column is $data[$row][$column]\n";    } }

    I understand till here how to access elements of

    arrays of arrays.I would like to compare each of

    the element in the array with the elements of the

    next array,and depending upon the number of

    matches, I would like to print it in the following

    way. Any help in this regard would be

    appreciated, as i am trying to get a clear concept

    of arrays of arrays.

    OUTPUT:

    A B C D E F G

    A D E F G

    B E F

    A C

    G

    M N O

    M N

    O

[reply]
[d/l]
[select]
      Sorry. I do not understand your algorithm, ie method to generate the next line from the previous line. Start with some text that explains how to get line 1, 2, 3, 4 etc.
[reply]

In Section Seekers of Perl Wisdom