2colours Raku solutions added

2 files changed, 38 insertions, 0 deletions

diff --git a/challenge-151/2colours/raku/ch-1.raku b/challenge-151/2colours/raku/ch-1.raku
new file mode 100755
index 0000000000..c572d39c71
--- /dev/null
+++ b/challenge-151/2colours/raku/ch-1.raku
@@ -0,0 +1,17 @@
+#!/usr/bin/env raku
+
+multi minimum-depth(@tree where *.first == 0 --> 0) {}
+multi minimum-depth(@tree where * == 1 --> 1) {}
+multi minimum-depth(@tree) { minimum-depth(@tree.skip.List, 1, (True,)) }
+multi minimum-depth((), $current-assumption, @) { $current-assumption }
+multi minimum-depth((@head, *@tail), $current-assumption, @prev-filter) {
+  my @common-children = @head.rotor(2, :partial);
+  when +@common-children <= (-1 R// @prev-filter.first: *.so, :end, :k) { $current-assumption }
+  when @prev-filter Z&& @common-children
+    andthen .grep: * !=== False
+    andthen .map: *.all eq '*'
+    andthen .any { $current-assumption }
+  minimum-depth(@tail, $current-assumption + 1, @head.map(* ne '*').List);
+}
+my @tree-lines = prompt('Input: ').split('|').map(*.words.List);
+say "Output: {minimum-depth(@tree-lines)}";
diff --git a/challenge-151/2colours/raku/ch-2.raku b/challenge-151/2colours/raku/ch-2.raku
new file mode 100755
index 0000000000..d43a80019f
--- /dev/null
+++ b/challenge-151/2colours/raku/ch-2.raku
@@ -0,0 +1,21 @@
+#!/usr/bin/env raku
+
+use experimental :cached;
+
+#`{ This looks very elegant but unfortunately, cached is broken with multiple dispatch and therefore the calls grow exponentially
+multi max-sum(($x1, $x2, *@tl)) { max(max-sum(($x2, |@tl)), $x1 + max-sum(@tl)) }
+multi max-sum(($x,)) {$x}
+multi max-sum(() --> 0) {}
+}
+
+sub max-sum(@list) is cached {
+  given @list {
+    when 0 { 0 }
+    when 1 { @list.first }
+    default { max max-sum(@list.skip), @list.first + max-sum(@list.skip: 2) } 
+  }
+}
+
+say max-sum((1,3,2,4,4,1,9,1)); #16
+say max-sum((2, 4, 5)); #7
+say max-sum((4, 2, 3, 6, 5, 3)); #13