1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/sieve_of_eratosthenes/sieve.pl	Mon May 04 17:23:45 2015 -0500
     1.3 @@ -0,0 +1,72 @@
     1.4 +#!/usr/bin/env perl
     1.5 +
     1.6 +use strict;
     1.7 +use warnings;
     1.8 +
     1.9 +sub sieve_of_eratosthenes {
    1.10 +    my $limit = shift;
    1.11 +
    1.12 +    my @nums = [];
    1.13 +    for ( my $i = 2; $i <= $limit; $i ++ ) {
    1.14 +        $nums[$i] = 0;
    1.15 +    }
    1.16 +
    1.17 +    my $factor = 2;
    1.18 +    my $done = 0;
    1.19 +    while (not $done) {
    1.20 +        my $i = $factor;
    1.21 +        while ( $i <= $limit ) {
    1.22 +            $i += $factor;
    1.23 +            $nums[$i] = 1;
    1.24 +        }
    1.25 +
    1.26 +        my $new_factor = $factor + 1;
    1.27 +        for ( my $j = $new_factor ; $j <= $limit; $j++ ) {
    1.28 +            if ( $nums[$new_factor] == 0 ) {
    1.29 +                last;
    1.30 +            }
    1.31 +        }
    1.32 +        if ( $new_factor > $limit ) {
    1.33 +            $done = 1;
    1.34 +        }
    1.35 +        else {
    1.36 +            $factor = $new_factor;
    1.37 +        }
    1.38 +    }
    1.39 +
    1.40 +    my @primes;
    1.41 +    for ( my $i = 2; $i <= $limit; $i ++ ) {
    1.42 +        ( $nums[$i] == 0 ) and push @primes, $i;
    1.43 +    }
    1.44 +    return \@primes;
    1.45 +}
    1.46 +
    1.47 +sub sieve2 {
    1.48 +    my $limit = shift;
    1.49 +
    1.50 +    my @nums = [];
    1.51 +    for ( my $i = 2; $i <= $limit; $i ++ ) {
    1.52 +        $nums[$i] = 1;
    1.53 +    }
    1.54 +
    1.55 +    for ( my $i = 2; $i <= sqrt($limit); $i ++ ) {
    1.56 +        if ( $nums[$i] ) {
    1.57 +            for ( my $j = $i * $i ; $j <= $limit; $j += $i ) {
    1.58 +                $nums[$j] = 0;
    1.59 +            }
    1.60 +        }
    1.61 +    }
    1.62 +
    1.63 +    my @primes;
    1.64 +    for ( my $i = 2; $i <= $limit; $i ++ ) {
    1.65 +        ( $nums[$i] ) and push @primes, $i;
    1.66 +    }
    1.67 +    return \@primes;
    1.68 +}
    1.69 +
    1.70 +my $primes = sieve2( $ARGV[0] );
    1.71 +#my $primes = sieve_of_eratosthenes( $ARGV[0] );
    1.72 +
    1.73 +foreach my $prime (@{$primes}) {
    1.74 +    print "$prime\n";
    1.75 +}