add verbose mode

1 files changed, 12 insertions, 1 deletions

diff --git a/challenge-090/alexander-pankoff/perl/ch-2.pl b/challenge-090/alexander-pankoff/perl/ch-2.pl
index eb588779f8..a66c4feea7 100755
--- a/challenge-090/alexander-pankoff/perl/ch-2.pl
+++ b/challenge-090/alexander-pankoff/perl/ch-2.pl
@@ -10,6 +10,8 @@ use List::Util qw(sum0);
 
 use Test::Simple tests => 20;
 
+use constant VERBOSE => $ENV{VERBOSE} // 0;
+
 {
     for ( 0 .. 19 ) {
         my ( $a, $b ) = map { int( rand( 1000 ) ) + 1 } 0 .. 1;
@@ -19,7 +21,16 @@ use Test::Simple tests => 20;
 }
 
 sub ethopian_mul ( $a, $b ) {
-    return sum0( map { $_->[1] } grep { odd( $_->[0] ) } ethopian_mul_chain( $a, $b ) );
+    my @chain = ethopian_mul_chain( $a, $b );
+    verbose( "halving $a, doubling $b, till $a becomes 1" );
+    verbose( $_->[0] . ' & ' . $_->[1] ) for @chain;
+
+    my @filtered = map { $_->[1] } grep { odd( $_->[0] ) } @chain;
+    verbose( "taking right values where left value is odd" );
+    verbose( $_ ) for @filtered;
+    my $product = sum0( @filtered );
+    verbose( "product is $product" );
+    return $product;
 }
 
 sub ethopian_mul_chain ( $a, $b ) {