Hi Monks,

I'm trying to compare two arrays and find their "intersection". List::Compare has so far proved very useful, however I now need a non-unique intersection.
Example code:

#!/usr/bin/perl

use strict;
use List::Compare;

my @temp = ( 'test', 'test1', 'test', 'test2', 'test2', 'test' );
print "----------------------\nContents of Temp Array\n";
print "\t", $_, "\n" foreach (@temp);

my @temp2 = ( 'test1', 'test2', 'test2' );
print "----------------------\nContents of Temp2 Array\n";
print "\t", $_, "\n" foreach (@temp2);

my $lc = List::Compare->new('--unsorted', \@temp, \@temp2);

my @intersection = $lc->get_intersection;
print "----------------------\nThe (Unique) Intersection of Temp and T
+emp2 Arrays\n";
print "\t", $_, "\n" foreach (@intersection);

exit;
[download]

This returns:

----------------------
Contents of Temp Array
        test
        test1
        test
        test2
        test2
        test
----------------------
Contents of Temp2 Array
        test1
        test2
        test2
----------------------
The (Unique) Intersection of Temp and Temp2 Arrays
        test1
        test2

However I need the Intersection to look like:

The Intersection of Temp and Temp2 Arrays
        test1
        test2
        test2

as test2 appeared twice in both lists.

I cant find a way to do this with List::Compare, so can anyone suggest anything?

Cheers,
Reagen

Update: I've figured out a way to do it As pointed out by Sidhekin, this doesnt work.

my %temp=map{$_ =>1} @temp;
my %temp2=map{$_=>1} @temp2;
my @non_unique_intersection = grep( $temp{$_}, @temp2 );
print "----------------------\nThe Non-Unique Intersection of Temp and
+ Temp2 Arrays\n";
print "\t", $_, "\n" foreach (@non_unique_intersection);
[download]

but would still be interested in how you would go about it...

For bonus points can anyone suggest a way to get the following:
- The non-unique leftover from @temp; and,
- The non-unique leftover from @temp2.

I tried the following which doesnt work...

my @non_unique_Lonly = @temp;
for (my $i=0;$i<scalar(@non_unique_Lonly);$i++){
  delete $non_unique_Lonly[$i] if ( grep $_ eq $non_unique_Lonly[$i], 
+@non_unique_intersection );
} # end-for
print "----------------------\nThe Non-Unique Leftover from Temp\n";
print "\t", $_, "\n" foreach (@non_unique_Lonly);
[download]

Update 2: This works but seems long winded...

my @non_unique_Lonly = @temp;
my @temp_intersection = @non_unique_intersection;
for (my $i=0;$i<scalar(@non_unique_Lonly);$i++){
  for (my $j=0;$j<scalar(@temp_intersection);$j++){
    if ( grep $_ eq $non_unique_Lonly[$i], @temp_intersection ) {
      delete $non_unique_Lonly[$i];
      delete $temp_intersection[$j];
      last;
    } # end-if
  } # end-for
} # end-for
print "----------------------\nThe Non-Unique Leftover from Temp\n";
print "\t", $_, "\n" foreach (@non_unique_Lonly);
[download]

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