$pattern_sum += @pattern_vector;
$upper_bound  = $pattern_sum + $FUZZ * @pattern_vector;
$lower_bound  = $pattern_sum + $FUZZ * @pattern_vector;

BUCKET: for my $bucket (@buckets) {
   my $bucket_sum += @{$bucket->[0]};
   next BUCKET 
       if ($bucket_sum > $upper_bound || $bucket_sum < $lower_bound);
   # found, do something
}