140 add helper binary_to_decimal

1 files changed, 30 insertions, 0 deletions

diff --git a/challenge-140/jake/perl/bin2dec.pl b/challenge-140/jake/perl/bin2dec.pl
new file mode 100644
index 0000000000..7fecc9ce09
--- /dev/null
+++ b/challenge-140/jake/perl/bin2dec.pl
@@ -0,0 +1,30 @@
+#!/r/bin/perl
+use strict;
+use warnings;
+
+# get input
+print "binary number a: ";
+my $a = <STDIN>;
+chomp $a;
+
+my $a_decimal = binary_to_decimal ( $a, 0, 0 );
+print "$a_decimal\n";
+
+sub binary_to_decimal {
+    my ( $binary_number, $power, $acc, $tail ) = @_;
+    print "begin sub with $binary_number\n";
+    return $acc if $binary_number eq '';
+    $tail = chop ($binary_number);
+    if ( $tail == 1 ) {
+    print "if with $binary_number\n";
+        $acc += 2**$power;
+        $power++;
+        return binary_to_decimal ( $binary_number, $power, $acc );
+    }
+
+    if ( $tail == 0 ) {
+    print "elsf with $binary_number\n";
+        $power++;
+        return binary_to_decimal ( $binary_number, $power, $acc );
+    }
+}
\ No newline at end of file