- Updated solution by Colin Crain.

1 files changed, 16 insertions, 5 deletions

diff --git a/challenge-194/colin-crain/perl/ch-2.pl b/challenge-194/colin-crain/perl/ch-2.pl
index 8fb41128d1..c248a6156b 100755
--- a/challenge-194/colin-crain/perl/ch-2.pl
+++ b/challenge-194/colin-crain/perl/ch-2.pl
@@ -117,25 +117,34 @@ sub free_eq ( $str ) {
         say "f_incidence: freq { $_ } => $f_incidence{$_} times" 

             for keys %f_incidence;}

 

+    my @counts  = sort {$a<=>$b} keys %f_incidence;

+    my @letters = keys %freq;

+    

     ## CASE 1: single frequency only

-    my @counts = sort {$a<=>$b} keys %f_incidence;

-    return 1 if  @counts    == 1 

-             and $counts[0] == 1 

-             and keys %freq > 1;

+    if (@counts == 1) {

+    

+        ## all the letters are different

+        return 1 if $counts[0] == 1 and @letters > 1;

+        

+        ## all the letters are the same (but not only one letter)

+        return 1 if $counts[0] > 1  and $counts[0] == length( $str );

+    }

    

     ## CASE 2: two frequencies

     if (@counts == 2) {

 

         ## if at least one of the two frequency classes has only one member

         ## it can be removed

-        for (keys %freq) { return 1 if $freq{$_} == 1 }

+        for (@letters) { return 1 if $freq{$_} == 1 }

 

         ## if one frequency incidence is one greater than the other and has

         ## exactly one more element in it

         return 1 if  $counts[0] + 1           == $counts[1] 

                  and $f_incidence{$counts[1]} == 1; 

     } 

+    

     return 0; 

+    

 }

 

 

@@ -159,6 +168,8 @@ is free_eq ( 'aabbccdddeee' ),  0,  'three doubles and two three counts - fail';
 is free_eq ( 'aabbccddd' ),     1,  'three doubles and one three count  - true';

 is free_eq ( 'abcd'    ),       1,  'unique chars';

 is free_eq ( 'a'    ),          0,  'only one char';

+is free_eq ( 'aaaaaaa'    ),    1,  'many of only one char';

+is free_eq ( 'aaaabbbb'    ),   0,  'pair of 4s';

 

 

 done_testing();