O and X's

1 files changed, 30 insertions, 0 deletions

diff --git a/challenge-077/simon-proctor/raku/ch-2.raku b/challenge-077/simon-proctor/raku/ch-2.raku
new file mode 100644
index 0000000000..60c94c7469
--- /dev/null
+++ b/challenge-077/simon-proctor/raku/ch-2.raku
@@ -0,0 +1,30 @@
+#!/usr/bin/env raku
+
+use v6;
+
+my %*SUB-MAIN-OPTS = :named-anywhere;
+
+#| Given a width and a list of O and X's
+#| Makes a grid of the given width and counts the number of X's not touching any others
+sub MAIN(
+    UInt $width, #= Width of the grid
+    :v(:$verbose) = False, #= Prints the Grid
+    *@cells where { "O"|"X" ~~ $_.all && $_.elems %% $width && $_.elems >= $width }
+) {
+    my @grid = @cells.rotor($width);
+    @grid.map( *.join(" ")).join("\n").say if $verbose;
+
+    my $count = 0;
+    for (0..^$width X, 0..^@grid.elems) -> @vec {
+        $count++ if @grid[@vec[1]][@vec[0]] ~~ "X" ~~ none(surrounding-cells( @vec, @grid ));
+    }
+    say $count;
+}
+
+sub surrounds( @vec ) {
+    (-1..1 X, -1..1).grep( { ! ( $_[0] == $_[1] == 0 ) } ).map( { [ $_[0]+@vec[0], $_[1]+@vec[1] ] } ).grep( { $_[0]&$_[1] >= 0 } );
+}
+
+sub surrounding-cells( @vec, @grid ) {
+    surrounds(@vec).map( -> ($x,$y) { @grid[$y][$x] } ).grep( { defined $_ } );
+}