Merge pull request #3864 from andemark/branch-for-challenge-107

ch-1.raku again...

1 files changed, 26 insertions, 5 deletions

diff --git a/challenge-107/mark-anderson/raku/ch-1.raku b/challenge-107/mark-anderson/raku/ch-1.raku
index 559f74d305..816d8c0ca5 100644
--- a/challenge-107/mark-anderson/raku/ch-1.raku
+++ b/challenge-107/mark-anderson/raku/ch-1.raku
@@ -1,13 +1,34 @@
 #!/usr/bin/env raku
 
-say (^Inf).grep(&self-descriptive).head(3);
+say (1..36).map(&self-descriptive).flat.head(3);
 
-sub self-descriptive($n)
+multi self-descriptive($base where * == 1|2|3|6)
 {
-    for ^$n.chars
+    Empty;
+}
+
+multi self-descriptive($base where * == 4|5)
+{
+    my $start = (1         ~ 0 x $base - 1).parse-base($base);
+    my $end   = ($base - 1 ~ 0 x $base - 1).parse-base($base);
+
+    gather 
     {
-        return False unless $n.substr($_, 1) == $n.indices($_);
+        while $start < $end
+        {
+            my $multiple = $start.base($base);
+
+            take $multiple if all map 
+            { 
+                $multiple.substr($_, 1) == $multiple.indices($_) 
+            }, ^$base; 
+
+            $start += $base;
+        }
     }
+}
 
-    True;
+multi self-descriptive($base)
+{
+    ($base - 4).base(36) ~ 21 ~ 0 x $base - 7 ~ 1000;
 }