Merge pull request #8449 from arnesom/branch-for-challenge-227

Arne Sommer

7 files changed, 132 insertions, 0 deletions

diff --git a/challenge-227/arne-sommer/blog.txt b/challenge-227/arne-sommer/blog.txt
new file mode 100644
index 0000000000..1f0fed48d2
--- /dev/null
+++ b/challenge-227/arne-sommer/blog.txt
@@ -0,0 +1 @@
+https://raku-musings.com/13th-roman.html
diff --git a/challenge-227/arne-sommer/raku/ch-1.raku b/challenge-227/arne-sommer/raku/ch-1.raku
new file mode 100755
index 0000000000..28e1f87ba3
--- /dev/null
+++ b/challenge-227/arne-sommer/raku/ch-1.raku
@@ -0,0 +1,5 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (Int $year where 1753 <= $year <= 9999 = Date.today.year);
+
+say (1 .. 12).grep({Date.new(year => $year, month => $_, day => 13).day-of-week == 5 }).elems;
diff --git a/challenge-227/arne-sommer/raku/ch-2.raku b/challenge-227/arne-sommer/raku/ch-2.raku
new file mode 100755
index 0000000000..5e2f623e8e
--- /dev/null
+++ b/challenge-227/arne-sommer/raku/ch-2.raku
@@ -0,0 +1,22 @@
+#! /usr/bin/env raku
+
+use lib "lib";
+
+use Number::Roman :to, :from;
+
+unit sub MAIN (Str $first, Str $operator, Str $second);
+
+my $f = from-roman($first);
+my $s = from-roman($second);
+
+given $operator
+{
+  when '+'  { say to-roman($f +  $s) };
+  when '-'  { say to-roman($f -  $s) };
+  when 'x'  { say to-roman($f *  $s) };
+  when '*'  { say to-roman($f *  $s) };
+  when 'xx' { say to-roman($f ** $s) };
+  when '**' { say to-roman($f ** $s) };
+  when '/'  { say to-roman($f / $s) };
+  default   { die "unknown operator"; }
+}
diff --git a/challenge-227/arne-sommer/raku/friday-13th b/challenge-227/arne-sommer/raku/friday-13th
new file mode 100755
index 0000000000..510fc0fe8a
--- /dev/null
+++ b/challenge-227/arne-sommer/raku/friday-13th
@@ -0,0 +1,17 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (Int $year where 1753 <= $year <= 9999 = Date.today.year, :v(:$verbose));
+
+my $fridays = 0;
+
+for 1 .. 12 -> $month
+{
+  my $date      = Date.new(year => $year, month => $month, day => 13);
+  my $is-friday = $date.day-of-week == 5;
+
+  $fridays++ if $is-friday;
+
+  say ": $date { $is-friday ?? " Friday" !! ""}" if $verbose;
+}
+
+say $fridays;
diff --git a/challenge-227/arne-sommer/raku/friday-13th-grep b/challenge-227/arne-sommer/raku/friday-13th-grep
new file mode 100755
index 0000000000..28e1f87ba3
--- /dev/null
+++ b/challenge-227/arne-sommer/raku/friday-13th-grep
@@ -0,0 +1,5 @@
+#! /usr/bin/env raku
+
+unit sub MAIN (Int $year where 1753 <= $year <= 9999 = Date.today.year);
+
+say (1 .. 12).grep({Date.new(year => $year, month => $_, day => 13).day-of-week == 5 }).elems;
diff --git a/challenge-227/arne-sommer/raku/lib/Number/Roman.rakumod b/challenge-227/arne-sommer/raku/lib/Number/Roman.rakumod
new file mode 100644
index 0000000000..e40e36dd1e
--- /dev/null
+++ b/challenge-227/arne-sommer/raku/lib/Number/Roman.rakumod
@@ -0,0 +1,60 @@
+unit module Number::Roman;
+
+our sub to-roman (Numeric $number is copy) is export(:to)
+{
+  return "nulla" if $number == 0;
+  return "non potest" unless 0 < $number < 3999;
+  return "non potest" unless $number.Int == $number;
+
+  my $string = "";
+  
+  while $number >= 1000 { $string ~= "M";  $number -= 1000; }
+  if $number >= 900     { $string ~= "CM"; $number -= 900; }
+  if $number >= 500     { $string ~= "D";  $number -= 500; }
+  if $number >= 400     { $string ~= "CD"; $number -= 400; }
+  while $number >= 100  { $string ~= "C";  $number -= 100; }
+  if $number >= 90      { $string ~= "XC"; $number -= 90; }
+  if $number >= 50      { $string ~= "L";  $number -= 50; }
+  if $number >= 40      { $string ~= "XL"; $number -= 40; }
+  while $number >= 10   { $string ~= "X";  $number -= 10; }
+  if $number >= 9       { $string ~= "IX"; $number -= 9; }
+  if $number >= 5       { $string ~= "V";  $number -= 5; }
+  if $number >= 4       { $string ~= "IV"; $number -= 4; }
+  while $number >= 1    { $string ~= "I";  $number -= 1; }
+
+  return $string;
+}
+
+my %value = (I => 1, V => 5, X => 10, L => 50, C => 100, D => 500, M => 1000);
+
+my Set $valid-roman = %value.keys.Set;
+
+my $current-value = Inf;
+
+our sub from-roman (Str $roman) is export(:from)
+{
+  my @digits = $roman.comb;
+
+  die "Non-Roman digit $_ detected." unless $valid-roman{$_} for @digits;
+
+  my $number = 0;
+
+  while @digits
+  {
+    my $current = @digits.shift;
+        
+    if @digits.elems
+    {
+      if %value{@digits[0]} > %value{$current}
+      {
+        $number += %value{@digits.shift} - %value{$current};
+        next;
+      }
+    }
+    $number += %value{$current};
+  }
+
+  return to-roman($number) eq $roman
+    ?? $number
+    !! die "Not a valid Roman Number: $roman";
+}
diff --git a/challenge-227/arne-sommer/raku/roman-maths b/challenge-227/arne-sommer/raku/roman-maths
new file mode 100755
index 0000000000..5e2f623e8e
--- /dev/null
+++ b/challenge-227/arne-sommer/raku/roman-maths
@@ -0,0 +1,22 @@
+#! /usr/bin/env raku
+
+use lib "lib";
+
+use Number::Roman :to, :from;
+
+unit sub MAIN (Str $first, Str $operator, Str $second);
+
+my $f = from-roman($first);
+my $s = from-roman($second);
+
+given $operator
+{
+  when '+'  { say to-roman($f +  $s) };
+  when '-'  { say to-roman($f -  $s) };
+  when 'x'  { say to-roman($f *  $s) };
+  when '*'  { say to-roman($f *  $s) };
+  when 'xx' { say to-roman($f ** $s) };
+  when '**' { say to-roman($f ** $s) };
+  when '/'  { say to-roman($f / $s) };
+  default   { die "unknown operator"; }
+}