140 add binary_to_decimal sub and addition

1 files changed, 50 insertions, 8 deletions

diff --git a/challenge-140/jake/perl/ch-1.pl b/challenge-140/jake/perl/ch-1.pl
index 59f7ccbecd..112b2e33b9 100644
--- a/challenge-140/jake/perl/ch-1.pl
+++ b/challenge-140/jake/perl/ch-1.pl
@@ -5,14 +5,31 @@ use warnings;
 # with this script you can add 2 binary numbers and get their sum as binary number
 # https://theweeklychallenge.org/blog/perl-weekly-challenge-140/#TASK1
 
-# get input
-print "decimal number: ";
-my $decimal_input = <STDIN>;
-chomp $decimal_input;
-my $a_binary = decimal_to_binary ( $decimal_input );
-printf ( "binary number: %i\n", $a_binary );
-
-# convert dec to bin
+# get input of 2 binary numbers
+
+print "binary number a: ";
+my $binary_input_a = <STDIN>;
+print "binary number b: ";
+my $binary_input_b = <STDIN>;
+chomp ( $binary_input_a, $binary_input_b );
+
+
+# convert binaries to decimals
+
+my $a_decimal = binary_to_decimal ( $binary_input_a );
+my $b_decimal = binary_to_decimal ( $binary_input_b );
+
+
+# perform regular addition on decimals
+
+my $result_decimal = $a_decimal + $b_decimal;
+
+
+# convert decimal results to binary
+
+my $result_binary = decimal_to_binary ( $result_decimal );
+print "$result_binary\n";
+
 sub decimal_to_binary {
     my ( $decimal ) = @_;
 
@@ -40,4 +57,29 @@ sub _decimal_to_binary {
 
     $power++;
     return _decimal_to_binary ( $power, $decimal_number, $binary_quantum );
+}
+
+sub binary_to_decimal {
+    my ( $binary ) = @_;
+
+    return _binary_to_decimal ( $binary, 0, 0 );
+}
+
+sub _binary_to_decimal {
+    my ( $binary_number, $power, $acc, $tail ) = @_;
+
+    return $acc if $binary_number eq '';
+
+    $tail = chop ($binary_number);
+
+    if ( $tail == 1 ) {
+        $acc += 2**$power;
+        $power++;
+        return _binary_to_decimal ( $binary_number, $power, $acc );
+    }
+
+    if ( $tail == 0 ) {
+        $power++;
+        return _binary_to_decimal ( $binary_number, $power, $acc );
+    }
 }
\ No newline at end of file