Some error corrections for Robbie Hatley's Perl solutions for The Weekly Challenge #268.

2 files changed, 5 insertions, 11 deletions

diff --git a/challenge-268/robbie-hatley/perl/ch-1.pl b/challenge-268/robbie-hatley/perl/ch-1.pl
index ccf51e42d6..8060986d2b 100755
--- a/challenge-268/robbie-hatley/perl/ch-1.pl
+++ b/challenge-268/robbie-hatley/perl/ch-1.pl
@@ -47,8 +47,8 @@ that common value is our "magic number", otherwise return "none":
    sub magic ($matref) {
       my @row1 = sort {$a<=>$b} @{$$matref[0]};
       my @row2 = sort {$a<=>$b} @{$$matref[1]};
-      my @diff = map {$$_[1]-$$_[0]} zip6 @row1, @row2;
-      all {$diff[0] == $_} @diff and return $diff[0]
+      my @diff = pairwise {$b-$a} @row1, @row2;
+      all {$_ == $diff[0]} @diff and return $diff[0]
       or return 'none';
    }
 
diff --git a/challenge-268/robbie-hatley/perl/ch-2.pl b/challenge-268/robbie-hatley/perl/ch-2.pl
index 2e59faae33..a882accdce 100755
--- a/challenge-268/robbie-hatley/perl/ch-2.pl
+++ b/challenge-268/robbie-hatley/perl/ch-2.pl
@@ -34,17 +34,11 @@ Output: (2, 1, 3, 2)
 
 --------------------------------------------------------------------------------------------------------------
 PROBLEM NOTES:
-This is equivalent to first sorting each array in increasing numeric order ("sort {$a<=>$b} @array"), then
-swapping pairs. Something like this:
+This is equivalent to first sorting each array in increasing numeric order ("sort {$a<=>$b} @array"),
+then swapping pairs:
 
    sub stairway (@array) {
-      my @zigzag = sort {$a<=>$b} @array;
-      for ( my $i = 0 ; $i <= $#zigzag - 1 ; $i += 2 ) {
-         my $temp = $zigzag[$i];
-         $zigzag[$i] = $zigzag[$i+1];
-         $zigzag[$i+1] = $temp;
-      }
-      return @zigzag;
+      pairmap {$b,$a} sort {$a<=>$b} @array;
    }
 
 --------------------------------------------------------------------------------------------------------------