Note that the primes subroutine is quite inefficient and returns 1 as well, which is usually not considered prime.
Here's a faster one:
#! /usr/bin/perl
use warnings;
use strict;
use feature qw{ say };
sub primes {
my $n = shift;
return if $n < 2;
my @primes = (2);
for my $i (3 .. $n) {
my $sqrt = sqrt $i;
my $notprime;
for my $p (@primes) {
last if $p > $sqrt;
$notprime = 1, last if 0 == $i % $p;
}
push @primes, $i unless $notprime;
}
return @primes
}
use List::Util qw{ sum };
sub primes_la {
# Copy your code here.
}
use Test::More tests => 1;
is_deeply([1, primes(10000)], [primes_la(10000)], 'same');
use Benchmark qw{ cmpthese };
cmpthese(-10,
{ ch => 'primes(10000)',
la => 'primes_la(10000)',
});
__END__
1..1
ok 1 - same
s/iter la ch
la 1.35 -- -99%
ch 1.06e-02 12662% --
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