Update all new Tasks

Task/Stern-Brocot-sequence/Perl/stern-brocot-sequence.pl

@@ -0,0 +1,36 @@
+use strict;
+use warnings;
+
+sub stern_brocot {
+    my @list = (1, 1);
+    sub {
+	push @list, $list[0] + $list[1], $list[1];
+	shift @list;
+    }
+}
+
+{
+    my $generator = stern_brocot;
+    print join ' ', map &$generator, 1 .. 15;
+    print "\n";
+}
+
+for (1 .. 10, 100) {
+    my $index = 1;
+    my $generator = stern_brocot;
+    $index++ until $generator->() == $_;
+    print "first occurrence of $_ is at index $index\n";
+}
+
+{
+    sub gcd {
+	my ($u, $v) = @_;
+	$v ? gcd($v, $u % $v) : abs($u);
+    }
+    my $generator = stern_brocot;
+    my ($a, $b) = ($generator->(), $generator->());
+    for (1 .. 1000) {
+	die "unexpected GCD for $a and $b" unless gcd($a, $b) == 1;
+	($a, $b) = ($b, $generator->());
+    }
+}