my $min = $values[0];
my $max = $values[0];

for my $value (@values[1 .. $#values]) {
    $min = $value if $value < $min;
    $max = $value if $value > $max ;
}

##</code><code>##

my $firstMatchline;

while (<DATA>) {
    next if !conditionMet($_);

    $firstMatchline //= $.;
    ...
}