challenge 137, raku solutions

2 files changed, 28 insertions, 0 deletions

diff --git a/challenge-137/feng-chang/raku/ch-1.raku b/challenge-137/feng-chang/raku/ch-1.raku
new file mode 100755
index 0000000000..b0de7b2725
--- /dev/null
+++ b/challenge-137/feng-chang/raku/ch-1.raku
@@ -0,0 +1,7 @@
+#!/bin/env raku
+
+put (1900..2100)
+    .grep({ Date("$_-12-31").week[1] == 53 })
+    .rotor(5, :partial)
+    .map({ $_.join(', ') })
+    .join(",\n");
diff --git a/challenge-137/feng-chang/raku/ch-2.raku b/challenge-137/feng-chang/raku/ch-2.raku
new file mode 100755
index 0000000000..7239d2cdb2
--- /dev/null
+++ b/challenge-137/feng-chang/raku/ch-2.raku
@@ -0,0 +1,21 @@
+#!/bin/env raku
+
+sub is-palindrome(UInt:D $n --> Bool:D) { $n.flip == $n }
+
+sub is-lynchel(UInt:D $n --> Bool:D) {
+    my UInt $m = $n;
+    my UInt $cnt;
+
+    repeat {
+        return False if is-palindrome($m);
+
+        $m += $m.flip;
+        ++$cnt;
+    } while $cnt < 500;
+
+    ! is-palindrome($m)
+}
+
+sub MAIN(UInt:D $n) {
+    put +is-lynchel($n);
+}