Task 2 done

1 files changed, 20 insertions, 21 deletions

diff --git a/challenge-074/luca-ferrari/raku/ch-2.p6 b/challenge-074/luca-ferrari/raku/ch-2.p6
index 78559cd9b0..2c0da8f0ea 100644
--- a/challenge-074/luca-ferrari/raku/ch-2.p6
+++ b/challenge-074/luca-ferrari/raku/ch-2.p6
@@ -2,33 +2,32 @@
 
 sub MAIN( Str $S where { $S.chars > 2 } ) {
 
-    my $fnr = Nil;
     my @result;
     my %counting;
     my @chars = $S.comb( '', :skip-empty );
-    for 0 ..^ @chars.elems {
-        my $current-char = @chars[ $_ ];
-
-        if ! $fnr {
-            $fnr = $current-char;
-        }
-        elsif $current-char ~~ $fnr {
-            my %counting;
-            %counting{ $_ }++ for @chars[ 0 .. $_ ];
-            $fnr = %counting.pairs.grep( { .value == 1 && .key !~~ $current-char } ).first.key // '#';
-            "selezionato $fnr".say;
-        }
-        elsif $_ !~~ $fnr  {
-            say "$fnr $current-char";
-            $fnr = $current-char;
-        }
-        else {
-            $fnr = '#';
-        }
 
+    for 0 ..^ @chars.elems -> $index {
+        my $current-char = @chars[ $index ];
 
-        @result.push: $fnr;
 
+
+        # if the result array is empty
+        # or the char is not in the array, it is
+        # ok to push
+        @result.push( $current-char ) && next if ! @result || ! @result.grep( * ~~ $current-char );
+
+
+        # if here I need to search for the first rightmost
+        # not repeating char so far
+        %counting = %();
+        %counting{ $_ }++ for $S.substr( 0 .. $index ).comb( '', :skip-empty );
+        my $fnr = $S.substr( 0 .. $index )
+                    .comb( '', :skip-empty )
+                    .reverse
+                    .grep( { %counting{ $_ }:exists && %counting{ $_ } == 1 } )
+                    .first // '#';
+
+        @result.push: $fnr;
     }
 
     @result.join.say;