Solution for first task

1 files changed, 32 insertions, 0 deletions

diff --git a/challenge-172/2colours/raku/ch-1.raku b/challenge-172/2colours/raku/ch-1.raku
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+#!/usr/bin/env raku
+
+constant @primes = (1 .. *).grep: &is-prime;
+
+multi prime-partition($sum, $count) {
+  gather samewith $sum, $count, 1, ()
+}
+
+#bound check (could be more accurate for sure)
+sub unfinishable($sum, $count, $chosen-prime) { $sum < $count * $chosen-prime }
+
+#terminating when done
+multi prime-partition($sum, 0, $, @rest) {
+  take @rest if $sum == 0;
+}
+
+#
+multi prime-partition($sum, $count, $lower-bound, @rest) {
+  my &finishable = { !unfinishable($sum, $count, $_) };
+  my @prime-range = lazy @primes.toggle: :off, * > $lower-bound;
+  @prime-range .= toggle: &finishable;
+  samewith $sum - $_, $count - 1, $_, (|@rest, $_) for @prime-range;  
+}
+
+sub MAIN(
+  Int $m,
+  Int $n
+) {
+  say "Input: \$m = $m, \$n = $n";
+  my $output = prime-partition($m, $n).map(*.join: ', ').join: ' or ';
+  say "Output: $output";
+}
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