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perl/Examples/Chap5/binary-1

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+
+
+###
+### binary1
+###
+
+## Chapter 5 section 4.2
+
+sub binary {
+  my ($n, $RETVAL) = @_;
+  $RETVAL = "" unless defined $RETVAL;
+  my $k = int($n/2);
+  my $b = $n % 2;
+  $RETVAL = "$b$RETVAL";
+  return $RETVAL if $n == 0 || $n == 1;
+  binary($k, $RETVAL);
+}