Challenge 227 Solutions (Raku)

1 files changed, 22 insertions, 21 deletions

diff --git a/challenge-227/mark-anderson/raku/ch-1.raku b/challenge-227/mark-anderson/raku/ch-1.raku
index a9b05ce374..ffd28592fc 100644
--- a/challenge-227/mark-anderson/raku/ch-1.raku
+++ b/challenge-227/mark-anderson/raku/ch-1.raku
@@ -11,9 +11,8 @@ is friday-the-thirteenths(9999), 1;
 for 1753..9999 -> $year 
 {
     my $d = Date.new(:$year);
-    my $dow = $d.day-of-week;
     my @d = map { $d.later(:month($_)) }, ^12;
-    say .fmt("%-15s") given $dow, +$d.is-leap-year, +@d.grep(*.day-of-week == 7)
+    say .fmt("%-15s") given $d.day-of-week, +$d.is-leap-year, +@d.grep(*.day-of-week == 7)
 }
 
 I used the program above (piped through sort -u) to create the chart below.
@@ -43,8 +42,27 @@ Day Of Week  Leap Year      Fri 13ths
 7            1              3
 --------------------------------------
 
-It looks like the sequence repeats every 400 years so this
-program should also work.
+That chart can be translated into the following program.
+
+sub friday-the-thirteenths($year where * ~~ 1753..9999)
+{
+    my $d = Date.new(:$year);
+    
+    given $d.day-of-week
+    {
+        when 1  { 2 }
+        when 2  { $d.is-leap-year ?? 1 !! 2 }
+        when 3  { $d.is-leap-year ?? 2 !! 1 }
+        when 4  { $d.is-leap-year ?? 2 !! 3 }
+        when 7  { $d.is-leap-year ?? 3 !! 2 }
+        default { 1 }
+    }
+}
+
+But it looks like the sequence repeats every 400 years 
+so this can be written without creating a Date object.
+
+=end com
 
 sub friday-the-thirteenths($year where * ~~ 1753..9999)
 {
@@ -72,20 +90,3 @@ sub friday-the-thirteenths($year where * ~~ 1753..9999)
         3 1 1 3 2 1 3 1 2 2 2 2 1 1 2 2 1 3 1 1
     >.Slip xx *
 }
-
-=end com
-
-sub friday-the-thirteenths($year where * ~~ 1753..9999)
-{
-    my $d = Date.new(:$year);
-    
-    given $d.day-of-week
-    {
-        when 1  { 2 }
-        when 2  { $d.is-leap-year ?? 1 !! 2 }
-        when 3  { $d.is-leap-year ?? 2 !! 1 }
-        when 4  { $d.is-leap-year ?? 2 !! 3 }
-        when 7  { $d.is-leap-year ?? 3 !! 2 }
-        default { 1 }
-    }
-}