2 files changed, 121 insertions, 0 deletions
diff --git a/challenge-104/cheok-yin-fung/perl/ch-1.pl b/challenge-104/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..111f6a72e4
--- /dev/null
+++ b/challenge-104/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,17 @@
+#!/usr/bin/perl 
+# The Weekly Challenge 104
+# FUSC Sequence
+
+use strict;
+use warnings;
+
+my @a = (0,1);
+
+for my $i (3..50) {
+    $a[$i] = $i % 2 == 0 ? $a[$i/2] : $a[($i-1)/2]+$a[($i+1)/2];
+}
+
+for my $i (0..50) {
+    printf "%3d %2d\n", $i, $a[$i];
+}
+
diff --git a/challenge-104/cheok-yin-fung/perl/ch-2.pl b/challenge-104/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..b55f1ba0f2
--- /dev/null
+++ b/challenge-104/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,104 @@
+#!/usr/bin/perl
+# The Weekly Challenge 104
+# NIM Game
+use strict;
+use warnings;
+
+my $remain = 12;
+
+my $player = int rand(2);
+
+print "                    NIM Game\n    ";
+print " |" x 12, "\n";
+
+#from task statment
+
+print 
+'For the purpose of this task, let assume you play against the machine.
+
+There are 3 simple rules to follow:
+
+a) You have 12 tokens
+b) Each player can pick 1, 2 or 3 tokens at a time
+c) The player who picks the last token wins the game
+
+
+For simplicity, we have already randomly assigned the player:
+';
+
+if ($player == 1) {
+    print " First Player: YOU;\nSecond Player: COMPUTER;\n";
+    your_decision();
+}
+else
+{
+    print " First Player: COMPUTER;\nSecond Player: YOU;\n";
+    machine_decision();
+}
+
+# =========================================================
+# ================ Subroutines ============================
+# =========================================================
+
+
+sub machine_decision {
+    my $m_take;
+    if ($remain % 4 != 0) {
+        $m_take = $remain % 4;
+    }
+    else {
+        $m_take = 1 + int rand(3);
+    }
+    print "The computer decides to take $m_take token";
+    print ($m_take == 1 ? "." : "s." );
+    print "\n";
+    pick($m_take, ($player+1) % 2);
+}
+
+sub your_decision {
+    print "Please input how many tokens you want to take: ";
+    my $inpt = <STDIN>;
+    chomp($inpt);
+    if (($inpt >= 4 or $inpt <= 0) || ($remain < $inpt)) {
+        print "WARN: invalid input; Please input again\n"; 
+        your_decision();
+    }
+    else {
+        pick(int $inpt, $player);
+    }
+}
+
+sub pick {
+    my $num = $_[0];
+    my $side = $_[1];
+    $remain -= $num;
+    die "Invalid operation!" if $remain < 0 || $num >= 4 || $num <= 0 ;
+
+    if ($remain == 0) {
+        endgame($side);
+    }
+
+    print "\n    ", "| "  x $remain;
+    print "\nNumber of tokens remain: $remain\n";
+    
+    if ($side == $player) {
+        machine_decision();
+    }
+    else {
+        your_decision();
+    }
+
+}
+
+sub endgame {
+    my $winner = $_[0];
+    print "The winner is ";
+    if ($winner == $player) {
+        print "YOU. \n"
+    } 
+    else {
+        print "the computer. \n" 
+    }
+    print "Good game. \n";
+    exit;
+}