2 files changed, 84 insertions, 0 deletions
diff --git a/challenge-012/feng-chang/perl5/ch-1.pl b/challenge-012/feng-chang/perl5/ch-1.pl
new file mode 100755
index 0000000000..21129a546b
--- /dev/null
+++ b/challenge-012/feng-chang/perl5/ch-1.pl
@@ -0,0 +1,72 @@
+#!/bin/env perl
+
+use Modern::Perl;
+use List::Util qw(min max);
+use POSIX;
+
+my @primes = (2, 3);
+
+sub more_primes {
+    my $to   = shift;
+    my $from = $primes[-1] + 1;
+    my $P;
+
+    do {
+        $P = $primes[-1];
+        my @a = ($P + 1) .. min($to, $P * $P);
+
+        for my $p (@primes) {
+            for (my $i = ceil($from / $p) * $p - $from; $i <= $to; $i += $p) {
+                $a[$i] = 0;
+            }
+        }
+
+        for my $i (@a) {
+            push(@primes, $i) if $i;
+        }
+    } while ($P * $P < $to);
+}
+
+sub is_prime {
+    my $n = shift;
+
+    my $e = int(sqrt($n));
+    more_primes($e) if $e > $primes[-1];
+
+    for my $p (@primes) {
+        last if $p > $e;
+        return 0 if $n % $p == 0;
+    }
+
+    return 1;
+}
+
+sub get_prime {
+    my $idx = shift;
+    return $primes[$idx] if $idx + 1 <= @primes;
+
+    do {
+        my $n = $primes[-1];
+        more_primes($n * $n);
+    } while ($idx + 1 > @primes);
+
+    return $primes[$idx];
+}
+
+if (@ARGV) {
+    my $n = $ARGV[0];
+    say "$n is ", is_prime($n) ? '' : 'not ', 'prime';
+    exit 0;
+}
+
+my $prod = 1;
+my $i    = 0;
+while (1) {
+    $prod *= get_prime($i);
+    print $primes[$i], ' ';
+    last unless is_prime($prod + 1);
+
+    ++$i;
+}
+
+say $prod + 1;
diff --git a/challenge-012/feng-chang/perl6/ch-1.p6 b/challenge-012/feng-chang/perl6/ch-1.p6
new file mode 100755
index 0000000000..5e58b20b50
--- /dev/null
+++ b/challenge-012/feng-chang/perl6/ch-1.p6
@@ -0,0 +1,12 @@
+#!/bin/env perl6
+
+my $euc = (^∞).grep: *.is-prime;
+
+my $prod = 1;
+for 0 .. ∞ -> Int $i {
+    $prod *= $euc[$i];
+    print $euc[$i], ' ';
+    last unless ($prod + 1).is-prime;
+
+    LAST { say $prod + 1 }
+}