Basically you're trying to merge all sets with related values.

Well, the below logic isn't pretty, but it works. Not sure what the problem was with your code

#!/usr/bin/perl -w

use strict;
use warnings;

my @array = map {[split / /]} (
    "11 12", "11 13", "9 8 7", "3 4", "11 4"
);

my %index = ();
for my $i (0..$#array) {
    for my $val (@{$array[$i]}) {
        push @{$index{$val}}, $i;
    }
}

for my $i (0..$#array) {
    my $arr = $array[$i] or next;
    $array[$i] = undef;

    my %values = ();
    for my $val (@$arr) {
        next if $values{$val}++;

        for my $ind (@{$index{$val}}) {
            my $related = $array[$ind] or next;
            $array[$ind] = undef;
            push @$arr, @$related;
        }
    }
    
    print join(' ', sort {$a <=> $b} keys %values), "\n";
}

[download]
Outputs 
3 4 11 12 13
7 8 9

[download]

In reply to Re: how to find combine common elements of an array? by wind
in thread how to find combine common elements of an array? by ihperlbeg

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