solutions week 175

2 files changed, 65 insertions, 0 deletions

diff --git a/challenge-175/wambash/raku/ch-1.raku b/challenge-175/wambash/raku/ch-1.raku
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index 0000000000..9c60d0524d
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+++ b/challenge-175/wambash/raku/ch-1.raku
@@ -0,0 +1,32 @@
+#!/usr/bin/env raku
+
+my $*this-year = Date.today.truncated-to('year');
+
+multi last-sundays (Int $year) {
+    samewith Date.new: :$year
+}
+
+multi last-sundays (Date $year = $*this-year) {
+    $year
+    andthen $_, *.later( :1month ) ...^ *
+    andthen .map: { .first-date-in-month .. .last-date-in-month }\
+    andthen .map: *.first: *.day-of-week == 7, :end
+    andthen .head: 12
+}
+
+multi MAIN (Bool :test($)!) {
+    use Test;
+    is last-sundays(2022), <
+        2022-01-30 2022-02-27
+        2022-03-27 2022-04-24
+        2022-05-29 2022-06-26
+        2022-07-31 2022-08-28
+        2022-09-25 2022-10-30
+        2022-11-27 2022-12-25
+    >;
+    done-testing;
+}
+
+multi MAIN (Int $year = 2022) {
+    put last-sundays $year;
+}
diff --git a/challenge-175/wambash/raku/ch-2.raku b/challenge-175/wambash/raku/ch-2.raku
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index 0000000000..153ea7a948
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+++ b/challenge-175/wambash/raku/ch-2.raku
@@ -0,0 +1,33 @@
+#!/usr/bin/env raku
+
+use Prime::Factor;
+
+sub euler ($n) {
+    prime-factors($n)
+    andthen .Bag
+    andthen .map: { (.key-1) * .key**(.value-1) }\
+    andthen [*] $_
+}
+
+constant @euler = (^∞).map: &euler;
+
+sub is-perfect-totient ($n) {
+    $n == sum @euler[$n], { @euler[$_] } ... 1
+}
+
+multi MAIN (Bool :test($)!) {
+    use Test;
+    is is-perfect-totient(4375), True;
+    is is-perfect-totient(5571), True;
+    is is-perfect-totient(729), True;
+    is is-perfect-totient(739),False;
+    done-testing;
+}
+
+multi MAIN ($k=20) {
+    3,5...∞
+    andthen .grep: &is-perfect-totient
+    andthen .head: $k
+    andthen .Supply
+    andthen .tap: *.put
+}