Sounds like a challenge. I took the dj_string routine on rosettacode and simplified it some.
sub sieve_s2 {
my ($n, $i, $s, $d, @primes) = (shift, 7);
my $sieve = '110010101110101110101110111110' .
'101111101110101110101110111110' x ($n/30);
for ($sieve) {
until (($s = $i*$i) > $n) {
$d = 2*$i;
do { substr($_, $s, 1, '1') } until ($s += $d) > $n;
1 while substr($_, $i += 2, 1);
}
$_ = substr($_, 1, $n);
push @primes, pos while m/0/gogo;
return @primes;
}
}
Pure perl isn't up to warp-speed, understandably.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|