Challenge 74 Solutions

1 files changed, 25 insertions, 0 deletions

diff --git a/challenge-074/mark-anderson/raku/ch-2.raku b/challenge-074/mark-anderson/raku/ch-2.raku
new file mode 100644
index 0000000000..2447d5f9a5
--- /dev/null
+++ b/challenge-074/mark-anderson/raku/ch-2.raku
@@ -0,0 +1,25 @@
+unit sub MAIN($string);
+
+my %seen;
+my $singles;
+
+my @first-non-repeatings = gather {
+    for 1..$string.chars -> $i {
+        my $letter = $string.substr($i-1, 1);    
+
+        %seen{$letter}++;
+
+        if %seen{$letter} == 1 {
+            $singles ~= $letter;
+            take $letter;
+        }
+
+        else {
+            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;