http://www.perlmonks.org?node_id=81705


in reply to (Golf): Sieve of Eratosthenes

Much worse than the previous offering and just plain bad approaches (what can I say--I'm bad at golf and I wanted to play with using an array. look here if you want to see some shorter solutions):

# Example use: @result = sieve(60); sub sieve { my$m=pop;my@l=(0..$m);for(my$x=0;$x<$m;$x++){next if($l[$x]<2);my $i=2 +;my$n=0;for(;$n<$m;$i++){$n=$x*$i;next if($n>$m);$l[$ n]=0}}@l=grep{$l[$_]}(0..$m) }
152.

# Example of use: sieve(60); sub sieve { my$m=pop;@_=(2..$m);for my $c(@_){my%b=map{$_,1}grep{($_%$c)==0}($c+1. +.$m);@_=grep{!$b{$_}}@_}die"@_\n" }
104.

Too bad we're not playing basketball.

Update

# Example of use: @result = sieve(60); sub sieve{ L:for(2..pop){for my $b(2..$_-1){next L if($_%$b<1)}push@_,$_}@_ }
65. Does not mark of multiples but tests each number (only as far as needed, at least), so not really allowed.