Factorions

1 files changed, 53 insertions, 0 deletions

diff --git a/challenge-153/0rir/raku/ch-2.raku b/challenge-153/0rir/raku/ch-2.raku
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+#!/usr/bin/env raku
+# :vim ft=raku sw=4 expandtab
+use v6.d;
+use MONKEY-SEE-NO-EVAL;
+
+constant \TEST=True;
+
+# Factorions
+
+$*ERR.print: "Warning: Postfix bang binds tighter than unary minus,\n"
+           ~ "         Use a function for general use.\n";
+
+my sub postfix:<!> ( Int $i --> Int ) {
+    state @f = 1,1,2,6;
+    while @f.end < $i {
+        @f.push: @f.end × (@f[@f.end -1] + @f[@f.end])
+    }
+    @f[$i];
+}
+
+my $n = (1..100000).pick;
+
+factorion( $n);
+
+exit unless TEST;
+
+sub factorion ( Int $n, Bool :$QUIET --> Bool) {
+    my Str $explan = (($n.split( '', :skip-empty)).join: '! + ') ~ '!'; 
+    my $output = EVAL( $explan);
+    my $ation = join ' + ',
+            ($explan.split( ' + ', :skip-empty)).map: { EVAL $_ };
+
+    unless $QUIET {
+        say "Input: \$n = $n\n"
+        ~ "Output: ", ($output==$n).Int(), "\n\n"
+        ~ "    Since $explan => $ation = $output";
+    }
+    $output == $n;
+}
+
+use Test;
+
+my @good = 1, 2, 145, 40585;
+
+plan 50000;
+
+for @good -> $x {
+    is factorion($x), $x == @good.any, "is a factorion";
+}
+for 0 .. 49999 {
+    next if $_ == @good.any;
+    is factorion($_, :QUIET ), False, 'is not a factorion';
+}