Merge pull request #2092 from andemark/branch-for-challenge-074

Branch for challenge 074

1 files changed, 20 insertions, 14 deletions

diff --git a/challenge-074/mark-anderson/raku/ch-2.raku b/challenge-074/mark-anderson/raku/ch-2.raku
index 2447d5f9a5..c572e643c3 100644
--- a/challenge-074/mark-anderson/raku/ch-2.raku
+++ b/challenge-074/mark-anderson/raku/ch-2.raku
@@ -1,25 +1,31 @@
-unit sub MAIN($string);
+sub MAIN($string) {
+    my @fnr-chars = gather {
+        for 1..$string.chars -> $i {
+            take fnr($string.substr(0, $i));
+        }
+    }
+
+    say @fnr-chars.join;
+}
 
-my %seen;
-my $singles;
+sub fnr($string) {
+    state %seen;
+    state $singles;
 
-my @first-non-repeatings = gather {
-    for 1..$string.chars -> $i {
-        my $letter = $string.substr($i-1, 1);    
+    my $letter = $string.substr($string.chars-1, 1);    
 
-        %seen{$letter}++;
+    %seen{$letter}++;
 
-        if %seen{$letter} == 1 {
+    given %seen{$letter} {
+        when 1 {
             $singles ~= $letter;
-            take $letter;
+            return $letter;
         }
-
-        else {
+        when 2 {
             my $idx = $singles.index($letter);
             $singles = $singles.substr(0, $idx) ~ $singles.substr($idx+1);
-            take $singles.substr($singles.chars-1, 1) // "#";
         }
     }
-}
 
-say @first-non-repeatings.join;
+    return $singles.substr($singles.chars-1, 1) // "#";
+}