tidied up output

1 files changed, 23 insertions, 19 deletions

diff --git a/challenge-162/james-smith/perl/ch-2.pl b/challenge-162/james-smith/perl/ch-2.pl
index 1cc3f6cb36..13e779d4d3 100644
--- a/challenge-162/james-smith/perl/ch-2.pl
+++ b/challenge-162/james-smith/perl/ch-2.pl
@@ -9,34 +9,38 @@ use Benchmark qw(cmpthese timethis);
 use Data::Dumper qw(Dumper);
 
 is( encrypt('playfair example', 'hide the gold in the tree stump'), 'bmodzbxdnabekudmuixmmouvif' );
+is( encrypt('playfajr example', 'hide the gold in the tree stump'), 'bmodzbxdnabekudmuixmmouvif' );
 is( decrypt('perl and raku',    'siderwrdulfipaarkcrw'),            'thewexeklychallengex' );
-is( encrypt('abc','xxx'),                                           'yyyyyy' );
-is( decrypt('abc','yyyyyy'),                                        'xxxxxx' );
+is( encrypt('abc','xxx'),                                           'xxxxxx' );
+is( decrypt('abc','xxxxxx'),                                        'xxxxxx' );
 done_testing();
 
-sub encrypt { return _crypt( 1,@_); }
-sub decrypt { return _crypt(-1,@_); }
-
 sub _crypt {
-  my($o,$key,$p,$out,@r,%l) = (shift,shift,0,'');                        ## Initialise variables and get mapping...
-  ($_ eq 'j' && ($_='i')), exists $l{$_} || ($l{$_}=[int $p/5,($p++)%5]) ## %l maps letter to position
-    for grep { /[a-z]/ } split(//,$key),'a'..'i','k'..'z';
-  $r[$l{$_}[0]][$l{$_}[1]]=$_ for keys %l;                               ## @r maps position to letter
-
-  my @seq = grep {/[a-z]/} split //, lc shift =~ s{j}{i}gr;              ## Prep sequence
-
-  while(my($m,$n)=splice @seq,0,2) {                                     ## Loop through letter pairs
-    unshift(@seq,$n), $n='x' if $n && $n eq $m && $o == 1;               ## Deal with case when both letters the same
-                                                                         ## Only do when encrypting..
-    $n ||= 'x';                                                          ## Pad if required...
-    $out.= $l{$m}[0] eq $l{$n}[0] ? $r[ $l{$m}[0]      ][($l{$m}[1]+$o)%5].
+  my( $o, $key, $p, $out, @r, %l ) = ( shift, shift, 0, '' );               ## Initialise variables and get mapping...
+  exists $l{$_} || ( $l{$_}=[int $p/5,($p++)%5] )                           ## %l maps letter to position
+    for grep { /[a-z]/ } split ( //, $key =~s/j/i/gr ), 'a'..'i', 'k'..'z'; ## values are ["row no", "column no"]
+  $r[ $l{$_}[0] ] [$l{$_}[1] ] = $_ for keys %l;                            ## @r maps position to letter, first
+                                                                            ## index row, 2nd column.
+  my @seq = grep {/[a-z]/} split //, lc shift =~ s{j}{i}gr;                 ## Prep sequence, remove non-letters,
+                                                                            ## lower case, convert "j" to "i"
+  while( my($m,$n) = splice @seq,0,2 ) {                                    ## Loop through letter pairs
+    unshift(@seq,$n), $n='x' if $n && $n eq $m && $o == 1;                  ## Deal with case when both letters the same
+                                                                            ## (Only do when encrypting..)
+    $n ||= 'x';                                                             ## Pad if required...
+
+    $out.= $m eq 'x' && $n eq 'x' ? 'xx'                                    ## Can still have a pair if first value is
+                                                                            ## "x" because this is then padded by "x"
+         : $l{$m}[0] eq $l{$n}[0] ? $r[ $l{$m}[0]      ][($l{$m}[1]+$o)%5]. ## Same row    - shift down  (or up)
                                     $r[ $l{$n}[0]      ][($l{$n}[1]+$o)%5]
-         : $l{$m}[1] eq $l{$n}[1] ? $r[($l{$m}[0]+$o)%5][ $l{$m}[1]      ].
+         : $l{$m}[1] eq $l{$n}[1] ? $r[($l{$m}[0]+$o)%5][ $l{$m}[1]      ]. ## Same column - shift right (or left)
                                     $r[($l{$n}[0]+$o)%5][ $l{$n}[1]      ]
-         :                          $r[ $l{$m}[0]      ][ $l{$n}[1]      ].
+         :                          $r[ $l{$m}[0]      ][ $l{$n}[1]      ]. ## o/w - other corners of square
                                     $r[ $l{$n}[0]      ][ $l{$m}[1]      ]
          ;
   }
   $out;
 }
 
+sub encrypt { return _crypt  1, @_; }
+sub decrypt { return _crypt -1, @_; }
+