2 files changed, 107 insertions, 0 deletions
diff --git a/challenge-169/cheok-yin-fung/perl/ch-1.pl b/challenge-169/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..ce4ccc7b79
--- /dev/null
+++ b/challenge-169/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,34 @@
+#!/usr/bin/perl
+# The Weekly Challenge 169
+# Task 1 Brilliant Numbers
+use v5.24.0;
+use warnings;
+
+my $req = $ARGV[0] || 20;
+
+my @prime = (2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 
+             41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97);
+
+die "You're asking too many, or I am too little!\n" 
+    if $req > 241;  # 21*20/2 +  21 + 4*3/2 + 4
+
+
+my $pt = 24;
+
+my @brilliant = (-1, 4, 6, 9, 10, 14, 15, 21, 25, 35, 49);
+
+my @temp;
+
+
+for my $i (4..$pt) {
+    for my $j ($i..24) {
+        my $product = $prime[$i]*$prime[$j];
+        push @temp, $product;
+    }
+}
+
+push @brilliant, sort {$a<=>$b} @temp;
+
+say join ", ", @brilliant[1..$req];
+
+
diff --git a/challenge-169/cheok-yin-fung/perl/ch-2.pl b/challenge-169/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..11d391bed2
--- /dev/null
+++ b/challenge-169/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,73 @@
+#!/usr/bin/perl
+# The Weekly Challenge 169
+# Task 2 Achilles Numbers
+use v5.24.0;
+use warnings;
+
+my $req = $ARGV[0] || 20;
+
+my @prime = (2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
+             41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97);
+
+my @achilles = (-1);
+
+
+my $found = 0;
+
+for my $i (2..-1+72*($prime[-1]+2)) {
+    my $powerful = 1;
+    my $imperfect;
+    my @prime_factors;
+    for (@prime) {
+        if ($i % $_ == 0) {
+            push @prime_factors, $_;
+            $powerful = 0 if ($i % ($_*$_) != 0);
+        }
+        last if !$powerful;
+    }
+    next if !$powerful;
+    next if scalar @prime_factors == 0;
+    my @ppower;
+    for my $pf (@prime_factors) {
+        my $ind = 2;
+        my $pp = $pf*$pf*$pf;
+        while ($i % $pp == 0) {
+            $ind++;
+            $pp = $pp*$pf;
+        } 
+        push @ppower, $ind;
+    }
+    next if scalar @ppower == 1;
+    $imperfect = gcd(@ppower);
+
+    if ($imperfect == 1) {
+        push @achilles, $i;
+        $found++;
+    }
+    last if $found == $req;
+}
+
+say join ", ", @achilles[1..$found];
+
+die "$found terms are shown. You're asking too many, or I am too little!\n"
+    if $req > $found;
+
+
+
+sub gcd {
+    my @num = @_;
+    return gcd_pair($num[0], $num[1]) if scalar @num == 2;
+    return gcd($num[0], gcd(@num[1..$#num]));
+}
+
+
+
+sub gcd_pair {
+    my $n0 = $_[0];
+    my $n1 = $_[1];
+    ($n0, $n1) = ($n1, $n0) if $n0 > $n1;
+    my $m = $n1 % $n0;
+    return $n0 if $m == 0;
+    return gcd_pair($m, $n0);
+} 
+