day24

2015/24/1.pl

@@ -10,11 +10,38 @@ use experimental qw/ signatures postderef /;
 
 use DDP;
 
+my @min = ( 1 ) x $goal;
 my $min = 1E99;
-aggregate( \@gifts, [shift @gifts], [] );
+
+aggregate( \@gifts, $goal );
 
 
-sub aggregate($gifts,$sofar,$next,$done=undef) {
+sub aggregate($gifts,$goal,@sofar) {
+    use DDP;
+    # p @_;
+
+    return if $goal < 0;
+
+    return if @sofar > @min;
+    return if product(@sofar) > $min;
+
+    if($goal == 0) {
+        @min = @sofar;
+        $min = product(@min);
+        say $min;
+        return;
+    }
+
+    return unless @$gifts;
+
+    my( $i, @gifts) = @$gifts;
+
+    aggregate( \@gifts, $goal - $i, @sofar, $i );
+    aggregate( \@gifts, $goal, @sofar );
+
+}
+
+__END__
 #    p @_;
     my $total = sum $sofar->@*;
 
@@ -49,7 +76,6 @@ sub aggregate($gifts,$sofar,$next,$done=undef) {
 
 }
 
-__END__
 
 my $min = 1E99;
 my @poss = possibilities(\@gifts,[]);

2015/24/2.pl

@@ -0,0 +1,43 @@
+use 5.20.0;
+
+my @gifts = map { 0+$_} <>;
+
+use List::AllUtils qw/ sum product min /;
+
+my $goal = sum(@gifts)/4;
+
+use experimental qw/ signatures postderef /;
+
+use DDP;
+
+my @min = ( 1 ) x $goal;
+my $min = 1E99;
+
+aggregate( \@gifts, $goal );
+
+
+sub aggregate($gifts,$goal,@sofar) {
+    use DDP;
+    # p @_;
+
+    return if $goal < 0;
+
+    return if @sofar > @min;
+    return if product(@sofar) > $min;
+
+    if($goal == 0) {
+        @min = @sofar;
+        $min = product(@min);
+        say $min;
+        return;
+    }
+
+    return unless @$gifts;
+
+    my( $i, @gifts) = @$gifts;
+
+    aggregate( \@gifts, $goal - $i, @sofar, $i );
+    aggregate( \@gifts, $goal, @sofar );
+
+}
+