my ($start, $end);
foreach my $i (0 .. $#range) {
    if($range[$i] >= 50000) {
        $start = $i;
        last;
    }
}
foreach my $i ($#range .. 0) {
    if($range[$i] <= 100000) {
        $end = $i;
        last;
    }
}

my @wanted_data = @range[$start .. $end];