From d6b54fcaf75a52c3b0d282a48b78c9ffe0be7492 Mon Sep 17 00:00:00 2001
From: Mark <53903062+andemark@users.noreply.github.com>
Date: Mon, 22 Apr 2024 13:41:50 +0000
Subject: Challenge 266 Solutions (Raku)

---
 challenge-266/mark-anderson/raku/ch-2.raku | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/challenge-266/mark-anderson/raku/ch-2.raku b/challenge-266/mark-anderson/raku/ch-2.raku
index aad59c7e67..51b303c159 100644
--- a/challenge-266/mark-anderson/raku/ch-2.raku
+++ b/challenge-266/mark-anderson/raku/ch-2.raku
@@ -170,24 +170,22 @@ nok X-matrix([
              ]),
     '21 X 21 non-diagonal non-zero';
 
+# This doesn't short circuit but I think I like it 
+# better than my previous solution anyway.
 sub X-matrix(+@m)
 {
-    my @diags = (0...@m.end) Z (@m.end...0);
+    my $diags := |((^@m) Z (^@m)), |((0...@m.end) Z (@m.end...0));
 
-    # handle the center diagonal and middle row
-    if @diags.end %% 2
-    {
-        return False unless all      @m[.[0]].splice(.[1],1,0).head, 
-                                none @m[.[0]] 
-        given @diags.splice(@m.elems div 2,1).head 
-    }
+    my @replace = 0 xx $diags;
+
+    @replace[@replace.elems div 4] = 1 if @m.end %% 2;
 
-    for @diags 
+    my @diags = gather for $diags Z @replace -> ($d, $r)
     {
-        return False unless all      @m[.[0]].splice(.[0],1,0).head,
-                                     @m[.[0]].splice(.[1],1,0).head, 
-                                none @m[.[0]]
+        my ($row, $col, $replace) = |$d, $r;
+        take @m[$row;$col];
+        @m[$row;$col] = $replace
     }
 
-    True
+    all(all |@diags, none @m[*;*])
 } 
-- 
cgit