Optimize

3 files changed, 24 insertions, 27 deletions

diff --git a/challenge-191/wlmb/perl/ch-2a.pl b/challenge-191/wlmb/perl/ch-2a.pl
index 340ea1ecd0..19c49b2d48 100755
--- a/challenge-191/wlmb/perl/ch-2a.pl
+++ b/challenge-191/wlmb/perl/ch-2a.pl
@@ -11,19 +11,19 @@ sub cute($n){ # iterator over cute sequences
     for my $position(0..$n-1){
         for(1..$n){
             push @{$sets[$position]}, $_ if ($position+1)%$_==0 || $_%($position+1)==0;
-	}
+        }
     }
     my $iter=Set::CrossProduct->new([@sets]);
     return sub {
-	ITER: while(my $tuple=$iter->get()){
+        ITER: while(my $tuple=$iter->get()){
             my @seen;
             for(@$tuple){
-	        next ITER if $seen[$_];
+                next ITER if $seen[$_];
                 ++$seen[$_];
             }
-	    return $tuple;
-	}
-	return;
+            return $tuple;
+        }
+        return;
     }
 }
 die << "EOF" unless @ARGV;
diff --git a/challenge-191/wlmb/perl/ch-2b.pl b/challenge-191/wlmb/perl/ch-2b.pl
index b0ae82e271..2e66f53809 100755
--- a/challenge-191/wlmb/perl/ch-2b.pl
+++ b/challenge-191/wlmb/perl/ch-2b.pl
@@ -11,7 +11,7 @@ sub cute($n){ # generate all cute sequences of length $n
     for my $position(0..$n-1){
         for(1..$n){ # Build sets of divisors and multiples of $position+1
             push @{$sets[$position]}, $_ if ($position+1)%$_==0 || $_%($position+1)==0;
-	}
+        }
     }
     my $x=reduce {cute_aux($a, $b)} [[]], @sets; # combine sets into cute sequences
     return $x;
@@ -24,9 +24,9 @@ sub cute_aux($seqs, $nums){ # combine an ongoing set of cute sequences with a se
         my $num=$tuple->[1];
         my @seen;
         map {$seen[$_]=1} @array; # Seen numbers
-	next if $seen[$num]; # Throw away repetitions
-	push @array, $num; # add number to current sequence
-	push @combined, [@array]; # add sequence to set of ongoing sequences
+        next if $seen[$num]; # Throw away repetitions
+        push @array, $num; # add number to current sequence
+        push @combined, [@array]; # add sequence to set of ongoing sequences
     }
     return [@combined];
 }
diff --git a/challenge-191/wlmb/perl/ch-2c.pl b/challenge-191/wlmb/perl/ch-2c.pl
index e212686d6a..ac2839648e 100755
--- a/challenge-191/wlmb/perl/ch-2c.pl
+++ b/challenge-191/wlmb/perl/ch-2c.pl
@@ -12,27 +12,24 @@ sub cute($n){ # generate all cute sequences of length $n
             push @{$sets[$position]}, $_ if ($position+1)%$_==0 || $_%($position+1)==0;
         }
     }
-    my $x=reduce {cute_aux($a, $b)} [[]], @sets; # combine sets into cute sequences
-    return $x;
-}
-sub cute_aux($seqs, $nums){ # combine an ongoing set of cute sequences with a set of numbers
-    my @combined =
-        map {
-            my $seq=$_;
+    my $x=reduce {
+        my @combined =
             map {
-                my @seq=@$seq;
-                my @seen;
-                map {$seen[$_]=1} @seq;
-                push @seq, $_;
-                $seen[$_]?():[@seq]
-            } @$nums
-    }
-    @$seqs;
-    [@combined];
+                my @seq=@$_;
+                map {
+                    my @seen;
+                    @seen[@seq]=(1)x@seq;
+                    $seen[$_]?():[@seq, $_]
+                } @$b
+        }
+        @$a;
+        [@combined];
+    } [[]], @sets; # combine sets into cute sequences
+    return $x;
 }
 die << "EOF" unless @ARGV;
 Usage: $0 N1 [N2...]
 to count the cute orderings of 1..Ni
 EOF
-die "Only numbers in the range 1..18 are allowed" unless all {1<=$_<=18} @ARGV;
+warn "Numbers beyond 18 will require patience" unless all {1<=$_<=18} @ARGV;
 say "$_ -> ", scalar @{cute($_)} for(@ARGV);