- Added solution by Ulrich Rieke.

1 files changed, 38 insertions, 0 deletions

diff --git a/challenge-070/ulrich-rieke/perl/ch-2.pl b/challenge-070/ulrich-rieke/perl/ch-2.pl
new file mode 100644
index 0000000000..07a8a46393
--- /dev/null
+++ b/challenge-070/ulrich-rieke/perl/ch-2.pl
@@ -0,0 +1,38 @@
+#!/usr/bin/perl ;
+use strict ;
+use warnings ;
+use feature 'say' ;
+
+#function to convert a binary string to a decimal number!
+#Of course, we have pack and unpack, but this seems less unwieldy...
+sub binToDecimal {
+  my $binary = shift ;
+  my $decimal = 0 ;
+  my $expo = 1 ;
+  my @reversed = reverse split (// , $binary) ;
+  for my $num ( @reversed ) {
+      $decimal += ( $expo * $num ) ;
+      $expo *= 2 ;
+  }
+  return $decimal ;
+}
+
+my $limit = $ARGV[ 0 ] ;
+my @current = ("0" , "1" ) ;
+my $n = 1 ;
+while ( $n < $limit ) {
+  for my $element ( reverse @current ) {
+      push( @current , $element ) ;
+  }
+  my $len = scalar @current ;
+  for my $i (0..$len / 2 - 1 ) {
+      $current[ $i ] = "0" . $current[ $i ] ;
+  }
+  for my $i ( $len / 2 .. $len - 1 ) {
+      $current[ $i ] = "1" . $current[ $i ] ;
+  }
+  $n++ ;
+}
+my @numbers = map { binToDecimal( $_ ) } @current ;
+say join (', ' , @numbers ) ;
+