use List::Util qw/sum min/;
use List::MoreUtils qw/pairwise/;

sub distance {
    my ($i, $j) = @_;
    no warnings;
    my $distance = sum pairwise { $a != $b } @$i, @$j;
    return $distance;
}

sub distance_to_any {
    my ($i, $l) = @_;
    return min ( map distance( $i, $_ ), @$l  );
}

print distance ([1, 2, 3, 4], [1, 8, 5, 7]) . "\n";
print distance_to_any ( [1, 2, 3, 4], [ [1, 8, 5, 7], [1, 2, 3, 9] ] )