use Benchmark qw(timethese);
use strict;
use warnings;

my @array = (1 .. 100000);
timethese(100, {granfather => \&grandfather, usual => \&usual});

sub grandfather {
	return 1 if grep {$_ == 100000} @array;
}

sub usual {
	for my $a (@array) {
		return 1 if ($a == 100000);
	}
	return 0;
}