Much better way of doing unique permutations

1 files changed, 1 insertions, 10 deletions

diff --git a/challenge-055/simon-proctor/raku/ch-2.p6 b/challenge-055/simon-proctor/raku/ch-2.p6
index aee75ea167..40d1f60451 100644
--- a/challenge-055/simon-proctor/raku/ch-2.p6
+++ b/challenge-055/simon-proctor/raku/ch-2.p6
@@ -17,16 +17,7 @@ multi sub MAIN( *@input where { $_.elems >= 2 && $_.all ~~ Int } ) {
 }
 
 sub unique-perms ( @input ) {
-    my %seen;
-    my @perms = @input.permutations;
-    gather {
-        while ( @perms ) {           
-            my $next = @perms.shift;
-            next if %seen{$next}:exists;
-            %seen{$next} = True;
-            take $next;        
-        }
-    }
+    @input.permutations.unique(:as(*.join(",")));
 }
 
 multi sub is-wave( 'lte', Int $a, Int $b where { $a <= $b } )          { True }