solution week 211-2 -- `combinations` works well

1 files changed, 16 insertions, 20 deletions

diff --git a/challenge-211/wambash/raku/ch-2.raku b/challenge-211/wambash/raku/ch-2.raku
index 57f2b1be23..ab6f2a060c 100644
--- a/challenge-211/wambash/raku/ch-2.raku
+++ b/challenge-211/wambash/raku/ch-2.raku
@@ -2,37 +2,33 @@
 
 sub average  { @^a.sum / @^a.elems }
 
-sub split-same-average-reducer ( @acc, $item, :$average, :$elems-limit ) {
-    @acc
-    andthen .grep: { .elems  < $elems-limit }\
-    andthen .map:  { |@^list, $item }\
-    andthen .grep: { .&average ≤ $average     }\
-    andthen |@acc, |$_
-}
-
 sub split-same-average (+@nums) {
     my $average = average @nums;
     my $elems-limit = @nums.elems div 2;
 
     @nums
-    andthen .sort
-    andthen (list(),), |$_
-    andthen .reduce: {split-same-average-reducer @^acc, $^item, :$average, :$elems-limit }\
+    andthen .combinations( 1..$elems-limit )
     andthen .first: { .&average  == $average },
 }
 
 multi MAIN (Bool :test($)!) {
     use Test;
-    is split-same-average(1, 2, 3, 4, 5, 6, 7, 8),(4,5);
+    is split-same-average(1, 2, 3, 4, 5, 6, 7, 8), (1,8);
     is split-same-average(1,3), Nil;
-    is split-same-average(<
-        44531 73257 49118 89580
-        25846 88015 19523 99285
-        75574 80036 10796 89896
-        77776 69138 75824 80610
-        47566  1623 20068  5294
-       >),
-       <10796 19523 20068 47566 69138 73257 75574 75824 80036 89896>;
+    subtest {
+        plan 2;
+        my @twenty = <
+            44531 73257 49118 89580
+            25846 88015 19523 99285
+            75574 80036 10796 89896
+            77776 69138 75824 80610
+            47566  1623 20068  5294
+        >;
+        with split-same-average(@twenty) {
+            is .&average, average(@twenty);
+            is .elems, @twenty.elems div 2;
+        }
+    }
     done-testing;
 }