Add TWC 218 solutions by Bruce Gray (Raku only).

2 files changed, 45 insertions, 0 deletions

diff --git a/challenge-218/bruce-gray/raku/ch-1.raku b/challenge-218/bruce-gray/raku/ch-1.raku
new file mode 100644
index 0000000000..2bef804180
--- /dev/null
+++ b/challenge-218/bruce-gray/raku/ch-1.raku
@@ -0,0 +1,17 @@
+sub task1 ( @ns ) {
+    return @ns.combinations(3).map({ [*] .list }).max;
+    # No time this week for efficient logic.
+}
+
+
+my @tests =
+    (   6, (  3,  1,  2)            ),
+    (  24, (  4,  1,  3,  2)        ),
+    (   3, ( -1,  0,  1,  3,  1)    ),
+    ( 216, ( -8,  2, -9,  0, -4, 3) ),
+;
+use Test;
+plan +@tests;
+for @tests -> ( $expected, @in ) {
+    is task1(@in), $expected;
+}
diff --git a/challenge-218/bruce-gray/raku/ch-2.raku b/challenge-218/bruce-gray/raku/ch-2.raku
new file mode 100644
index 0000000000..e6d42dac86
--- /dev/null
+++ b/challenge-218/bruce-gray/raku/ch-2.raku
@@ -0,0 +1,28 @@
+sub task2 ( @m_original ) {
+    my @m = @m_original.map: *.clone.Array;
+    sub flip_col ( $c ) { @m[$_][$c] = + ! @m[$_][$c] for    @m.keys }
+    sub flip_row ( $r ) { @m[$r][$_] = + ! @m[$r][$_] for @m[0].keys }
+
+    sub score ( ) {
+        return @m.map( *.join.parse-base(2) ).sum;
+    }
+
+    my $half = @m.elems / 2;
+
+    for @m.keys         -> $r { flip_row($r) if @m[$r][0]    == 0     }
+    for @m[0].keys.skip -> $c { flip_col($c) if @m».[$c].sum <  $half }
+
+    return score();
+}
+
+
+my @tests =
+    ( 39, ( (0,0,1,1), (1,0,1,0), (1,1,0,0) ) ),
+    (  1, ( (0,),                           ) ),
+    (  1, ( (1,),                           ) ),
+;
+use Test;
+plan +@tests;
+for @tests -> ( $expected, @in ) {
+    is task2(@in), $expected;
+}