pwc159 solution in perl

2 files changed, 53 insertions, 0 deletions

diff --git a/challenge-159/pokgopun/perl/ch-1.pl b/challenge-159/pokgopun/perl/ch-1.pl
new file mode 100644
index 0000000000..d5fd2115d3
--- /dev/null
+++ b/challenge-159/pokgopun/perl/ch-1.pl
@@ -0,0 +1,33 @@
+use strict;
+use warnings;
+#use Algorithm::Combinatorics qw/combinations/;
+#use Math::Prime::Util qw/is_prime/; 
+
+my @n = join("",@ARGV) =~ /^\d+$/ ? @ARGV : (5,7,4);
+
+foreach my $n (@n) {
+	print "Input: \$n = $n\n";
+
+### far too complicated, comes up with this before trying to read about Farey sequence
+#	my @fs;
+#	if ($n > 1) {
+#		@fs = sort{$a->[0]/$a->[1] <=> $b->[0]/$b->[1]} grep{ $_->[0] == 1 || ( (is_prime($_->[0]) || is_prime($_->[1]) ) && $_->[1] % $_->[0] != 0 ) } combinations([1..$n], 2);
+#	}
+#	@fs = ([0,1], @fs, [1,1]);
+#	printf "Output: %s\n\n", join(", ", map{join "/", @$_} @fs );
+
+### here is a simple algorithm found on https://en.wikipedia.org/wiki/Farey_sequence
+	my ($a,$b,$c,$d) = (0,1,1,$n);
+	printf "Output: %d/%d, %d/%d", $a, $b, $c, $d;
+	if ($n > 1){
+		{
+			my $k = int( ($n + $b) / $d );
+			($a,$b,$c,$d) = ($c,$d,$k*$c-$a,$k*$d-$b);
+			printf", %d/%d", $c, $d;
+			last if $c==1 && $d==1;
+			redo
+		}
+	}
+	print "\n\n";
+
+}
diff --git a/challenge-159/pokgopun/perl/ch-2.pl b/challenge-159/pokgopun/perl/ch-2.pl
new file mode 100644
index 0000000000..b8c4b7fa50
--- /dev/null
+++ b/challenge-159/pokgopun/perl/ch-2.pl
@@ -0,0 +1,20 @@
+use strict;
+use warnings;
+use Math::Factoring qw/factor/;
+
+my @n = join("",@ARGV) =~ /^\d+$/ ? @ARGV : (5,10,20);
+foreach my $n (@n) {
+
+	print "Input: \$n = $n\n";
+
+	my %factor;
+	$factor{$_}++ foreach factor($n);
+	
+	my @values = values %factor;
+	my $m = $n == 1 ? 1 :
+		scalar(grep{$_ > 1} @values) ? 0 :
+		@values % 2 ? -1 : 1;
+	
+	print "Output: $m\n\n";
+}
+