Weekly solutions (175) by 2colours

2 files changed, 36 insertions, 0 deletions

diff --git a/challenge-175/2colours/raku/ch-1.raku b/challenge-175/2colours/raku/ch-1.raku
new file mode 100755
index 0000000000..97ee0082d1
--- /dev/null
+++ b/challenge-175/2colours/raku/ch-1.raku
@@ -0,0 +1,15 @@
+#!/usr/bin/env raku
+
+sub MAIN(
+  Int $year = DateTime.now.year #= the year to check
+) {
+  (1 .. 12)
+    .map: {
+      Date.new: :$year, month => $_ andthen
+        .last-date-in-month andthen
+        .earlier: day => .day-of-week % 7
+    } andthen
+    .map: *.Str andthen
+    .join: "\n" andthen
+    .say;
+}
\ No newline at end of file
diff --git a/challenge-175/2colours/raku/ch-2.raku b/challenge-175/2colours/raku/ch-2.raku
new file mode 100755
index 0000000000..55f646345a
--- /dev/null
+++ b/challenge-175/2colours/raku/ch-2.raku
@@ -0,0 +1,21 @@
+#!/usr/bin/env raku
+
+use experimental :cached; 
+
+sub totient($n) is cached {
+  (1 ..^ $n)
+    .grep: * gcd $n == 1 andthen
+    .elems
+}
+
+sub iterated-totient-sum($n) {
+  $n, *.&totient ... 1 andthen
+    .skip
+    .sum
+}
+
+(1 .. *)
+  .grep: { .&iterated-totient-sum == $_} andthen
+  .head: 20 andthen
+  .join: ', ' andthen
+  .say;
\ No newline at end of file