Dadas 3 listas com números, encontrar os que aparecem em ao menos 2 listas \ Given 3 lists with numbers, find the ones that appear in at least 2 lists

gistfile1.txt

from the internet:

my @array1 = (1, 2, 3, 4);
my @array2 = (2, 3, 4);
my @array3 = (2, 5, 4);
my %original = ();
my @isect = ();

map { $original{$_} = 1 } @array1;
@isect = grep { $original{$_} } @array2;
@isect = grep { $original{$_} } @array3;

print Dumper(@isect);



----------------------------------------------------


use strict;
use warnings;
use Data::Printer;

my @a = (3,3,3,3,3,3,4,3);
my @b = (1,2,4,5,6);
my @c = (7,6,5,8,2,1);

my $items = { a => \@a, b => \@b, c => \@c };
my $r;
my $results             = {};
my @final_results       = ();

sub {
  my ( $list_letter, $list ) = @_;
  map {
    sub {
      $r->{$_}->{ $list_letter }->{ ocurrences } = ( exists $r->{$_}->{ $list_letter }->{ ocurrences } ) ? ($r->{$_}->{ $list_letter }->{ ocurrences }+1):1;
      if ( ! exists $results->{ $_ } && scalar keys $r->{$_} >= 2 ) {
        $results->{ $_ } = 1;
        push( @final_results, $_ );
      }
    }->()
  } @$list;
}->( $_, $items->{ $_ } ) for ( keys %$items ) ; 

warn p $r;
warn "Numbers that appear at least in 2 lists:";
warn p $results;
warn p @final_results;






--------------------------------------------------


use strict;
use warnings;
use Data::Printer;

my $b = [1..7];
my $c = [6..10];


sub intersect {
    my ( $items ) = @_;
    my $r;
    my $results = {};
    my @final_results = ();
    map {
        my $list_letter     = $_ ;
        my $list            = $items->{ $_ };
        map {
        sub {
            $r->{$_}->{ $list_letter }->{ ocurrences } =
                ( exists $r->{$_}->{ $list_letter }->{ ocurrences } )
                ? ($r->{$_}->{ $list_letter }->{ ocurrences }+1)
                : 1;
            if ( ! exists $results->{ $_ } && scalar keys $r->{$_} >= 2 ) {
                $results->{ $_ } = 1;
                push( @final_results, $_ );
            }
        }->();
        } @$list;
    } keys %$items;

    return \@final_results;
}

my $final_results = intersect( { b => $b, c => $c } );

warn p $final_results;