Prime number stuff

1 files changed, 23 insertions, 0 deletions

diff --git a/challenge-076/simon-proctor/raku/ch-1.raku b/challenge-076/simon-proctor/raku/ch-1.raku
new file mode 100644
index 0000000000..f9e5fb08ee
--- /dev/null
+++ b/challenge-076/simon-proctor/raku/ch-1.raku
@@ -0,0 +1,23 @@
+#!/usr/bin/env raku
+
+use v6;
+
+my %*SUB-MAIN-OPTS = :named-anywhere;
+
+#| Find 2 prime numbers greater than 1 that add up to the target number
+sub MAIN (
+    UInt $n where * >= 4, #= Target number (must be 4 or greater)
+    Bool :a(:$all) = False #= Print all possible combinations
+) {
+    my @primes = (2..$n-1).grep(*.is-prime);
+    for @primes.reverse -> $large {
+        next unless $large + any(@primes) == $n;
+        exit if $large < $n / 2;
+        for @primes -> $small {
+            if $large + $small == $n {
+                say "$large + $small = $n";
+                exit unless $all;
+            }
+        }
+    }
+}