100 items Rate brutal binary brutal 186657/s -- -16% binary 223418/s 20% -- 1000 items Rate brutal binary brutal 20574/s -- -87% binary 156038/s 658% -- 10000 items Rate brutal binary brutal 2167/s -- -98% binary 129102/s 5859% -- 100000 items Rate brutal binary brutal 169/s -- -100% binary 91542/s 54205% -- #### #!/usr/bin/perl use strict; use warnings; use Benchmark qw(cmpthese); my $limit = shift @ARGV || 1e4; my @a = sort {$a <=> $b } map { rand(2**20) } 0..($limit+1); print "Done generating list\n"; my $search_for = $a[int($limit / 3)]; sub brutal { for (0 .. $limit){ return $_ if $a[$_] > $search_for; } } sub binary { my ($left, $right) = (0, $limit); while ($right - $left > 10){ my $tmp = ($right+$left) / 2; if ($a[$tmp] > $search_for){ $right = $tmp; } else { $left = $tmp; } } for ($left .. $right){ return $_ if $a[$_] > $search_for; } } my $brutal = brutal(); my $binary = binary(); print $brutal, ' ', $binary, "\n"; cmpthese(-2, { binary => \&binary, brutal => \&brutal, });