Solution to challenge 44 task 2 in Raku by Noud

challenge-044/noud/raku/ch-2.p6

@@ -0,0 +1,57 @@
+# Make it $200
+#
+# You have only $1 left at the start of the week. You have been given an
+# opportunity to make it $200. The rule is simple with every move you can
+# either double what you have or add another $1. Write a script to help you get
+# $200 with the smallest number of moves.
+
+use experimental :cached;
+
+sub best-strategy($cur-val, $target=200) is cached {
+    if ($cur-val == $target) {
+        return 0, [];
+    }
+    if ($cur-val > $target) {
+        return -1, [];
+    }
+
+    my ($d1, $strat1) = best-strategy(2 * $cur-val, $target);
+    my ($d2, $strat2) = best-strategy($cur-val + 1, $target);
+
+    if ($d1 < 0 and $d2 < 0) {
+        return -1, [];
+    }
+    if ($d1 < 0) {
+        return $d2 + 1, (|($strat2), 2);
+    }
+    if ($d2 < 0) {
+        return $d1 + 1, (|($strat1), 1);
+    }
+    if ($d1 < $d2) {
+        return $d1 + 1, (|($strat1), 1);
+    }
+    else {
+        return $d2 + 1, (|($strat2), 2);
+    }
+}
+
+sub print-strategy($target) {
+    my ($a, $b) = best-strategy(1, $target);
+    say "In $a moves we can get $target dollar:";
+    my $r = '';
+    for $b.list -> $s {
+        if ($s == 1) {
+            $r ~= "2*(";
+        } else {
+            $r ~= "1+(";
+        }
+    }
+    $r ~= '1' ~ (')' x $a);
+    say $r ~ "=$target";
+}
+
+
+print-strategy(10);
+print-strategy(200);
+print-strategy(4200);
+print-strategy(12345);