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Re: Re: Prime Number Finder

by Anonymous Monk
on Nov 03, 2003 at 05:34 UTC ( #304017=note: print w/ replies, xml ) Need Help??


in reply to Re: Prime Number Finder
in thread Prime Number Finder

eisenstein's code is genius, to say the least. I found a different way of the sieve method, and am wondering which is more efficient. Thanks!

! usr/bin/perl -w use strict; sub prime{ my (@primes,%n); my $n=shift; foreach my $r(2..$n){ $n{$r}=1; } foreach my $x(2..int(sqrt($n))){ if($n{$x}){ my $a=2*$x; while ($a <= $n){ $n{$a}=undef; $a=$a+$x; } } } foreach my $x(2..$n){ if($n{$x}){ push( @primes, $x); } } return @primes; } #find to 100 print join ',',prime(100);


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