#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use constant MAX   => 20;
use constant EMPTY => "\0" x ((MAX / 8) + 1);

my @AoA = map [ map int rand 1 + MAX, 1 .. 4 ], 0 .. 1000;

my @vectors = (EMPTY) x (MAX + 1);

for my $num (0 .. MAX) {
    for my $pos (0 .. $#AoA) {
        vec($vectors[$num], $pos, 1) = grep($num == $_, @{ $AoA[$pos] }) ? 1 : 0;
    }
}

print "@$_; " for @AoA;
print "\n";

my $subarray = $AoA[0];
say "Selecting: @$subarray.";

my $result = EMPTY;
for my $num (@$subarray) {
    $result |= $vectors[$num];
}

for my $i (0 .. $#AoA) {
    say "@{ $AoA[$i] }" unless vec($result, $i, 1);
}