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2 files changed, 74 insertions, 0 deletions

diff --git a/challenge-159/0rir/raku/ch-1.raku b/challenge-159/0rir/raku/ch-1.raku
new file mode 100644
index 0000000000..3867df64f7
--- /dev/null
+++ b/challenge-159/0rir/raku/ch-1.raku
@@ -0,0 +1,22 @@
+#!/usr/bin/env raku
+# :vim ft=raku sw=4 expandtabs
+use v6.d;
+
+my $n = 7;
+
+say "Input: \$n = $n";
+
+my @farey
+    = sort { $^a <=> $^b }, gather
+        { for 1 .. $n -> $de {
+                for 0 .. $de -> $nu {
+                    take $nu/$de;
+                }
+            }
+        }.unique;
+
+for @farey -> $f is rw {
+    $f = $f.numerator ~ '/' ~ $f.denominator;
+}
+
+say "Output = @farey.join(', ').";
diff --git a/challenge-159/0rir/raku/ch-2.raku b/challenge-159/0rir/raku/ch-2.raku
new file mode 100644
index 0000000000..74750da588
--- /dev/null
+++ b/challenge-159/0rir/raku/ch-2.raku
@@ -0,0 +1,52 @@
+#!/usr/bin/env raku
+# :vim ft=raku sw=4 expandtabs
+use v6.d;
+use lib $?FILE.IO.parent(2).add("lib");
+use Test;
+
+constant TEST = False;
+
+my @exp = (  1, −1, −1,  0, −1,  1, −1,  0,  0,  1,
+            −1,  0, −1,  1,  1,  0, −1,  0, −1,  0,
+             1,  1, −1,  0,  0,  1,  0,  0, −1, −1,
+            −1,  0,  1,  1,  1,  0, −1,  1,  1,  0,
+            −1, −1, −1,  0,  0,  1, −1,  0,  0,  0 );
+
+sub MAIN( $n = 123456789 ) {
+    say prime-factors( $n);
+    say "Input: \$n = $n\nOutput = ", μ($n);
+}
+
+my @prime = grep {.is-prime}, (2,3,(* + 2) … ∞);
+
+sub prime-factors ( $int --> Array ) {
+    my $n = $int;
+    my @ret;
+    my $ix = 0;
+    while $n > 1 {
+        my $candi = @prime[$ix];
+        $ix++;
+        next unless ( $n %% $candi );
+        $ix = 0;
+        $n ÷= $candi;
+        @ret.push: $candi;
+    }
+    return @ret;
+}
+
+sub μ ( Int $n where $n > 0 --> Int ) {
+    return 1 if $n == 1;
+    my @prime-factor = prime-factors( $n);
+    return -1 if @prime-factor.elems == 1;
+    return  0 if @prime-factor.elems ≠ @prime-factor.unique.elems;
+    return  1 if @prime-factor.elems %% 2;
+    return -1;
+}
+
+if TEST {
+    plan @exp.elems;
+    for 1 … 50 -> $i {
+        is μ($i), @exp[$i - 1], prime-factors( $i);
+    }
+    done-testing;
+}