Merge pull request #5177 from Util/branch-for-challenge-137

Add Raku and Perl solutions for #137 by Bruce Gray

2 files changed, 46 insertions, 0 deletions

diff --git a/challenge-137/bruce-gray/raku/ch-1.raku b/challenge-137/bruce-gray/raku/ch-1.raku
new file mode 100644
index 0000000000..7acbafd81f
--- /dev/null
+++ b/challenge-137/bruce-gray/raku/ch-1.raku
@@ -0,0 +1,18 @@
+sub is-long ( Int $year --> Bool ) {
+    return Date.new("$year-12-31").week-number == 53;
+}
+
+use Test; plan 1;
+my @expected =
+    1903, 1908, 1914, 1920, 1925,
+    1931, 1936, 1942, 1948, 1953,
+    1959, 1964, 1970, 1976, 1981,
+    1987, 1992, 1998, 2004, 2009,
+    2015, 2020, 2026, 2032, 2037,
+    2043, 2048, 2054, 2060, 2065,
+    2071, 2076, 2082, 2088, 2093,
+    2099
+;
+
+my @got = grep &is-long, 1900 .. 2100;
+is-deeply @got, @expected;
diff --git a/challenge-137/bruce-gray/raku/ch-2.raku b/challenge-137/bruce-gray/raku/ch-2.raku
new file mode 100644
index 0000000000..2137e879f1
--- /dev/null
+++ b/challenge-137/bruce-gray/raku/ch-2.raku
@@ -0,0 +1,28 @@
+sub is-Lychrel-number ( Int $n is copy --> Bool ) {
+    my $iterations;
+    loop {
+        $n += $n.flip;
+
+        return False if $n eq $n.flip;
+        return True  if $n            >= 10_000_000
+                     or $iterations++ >  500;
+    }
+}
+
+use Test;
+my @tests = 
+    # From the task description:
+     56 => False,
+     57 => False,
+     59 => False,
+
+    # Added:
+    464 => True,    # Should be False, but not shown to be False inside the 10_000_000 limit, so True.
+    196 => True,    # Famously huge
+;    
+plan +@tests;
+
+for @tests -> ( :key($input), :value($expected) ) {
+    is is-Lychrel-number($input), $expected,
+        "is-Lychrel-number {$input.fmt('%3d')} == $expected";
+}