Task2 done.

1 files changed, 64 insertions, 0 deletions

diff --git a/challenge-062/luca-ferrari/raku/ch-2.p6 b/challenge-062/luca-ferrari/raku/ch-2.p6
new file mode 100644
index 0000000000..7679e57f2c
--- /dev/null
+++ b/challenge-062/luca-ferrari/raku/ch-2.p6
@@ -0,0 +1,64 @@
+#!env raku
+
+# Task 2
+# N-queens
+
+sub place-queen( @chessboard, $row, $column, $height, $dimension ){
+
+    for 0 ..^ $dimension {
+        @chessboard[ $row ][ $_ ][ $height ]    = False;
+        @chessboard[ $row ][ $column ][ $_ ]    = False;
+        @chessboard[ $_ ][ $column ][ $height ] = False;
+    }
+
+    # diagonal (only on one level)
+    for 0 ..^ $dimension {
+        @chessboard[ $row + $_ ][ $column + $_ ][ $height ] = False if ( $row + $_ < $dimension && $column + $_ < $dimension);
+        @chessboard[ $row - $_ ][ $column - $_ ][ $height ] = False if ( $row - $_ >= 0 && $column - $_ >= 0 );
+        @chessboard[ $row - $_ ][ $column + $_ ][ $height ] = False if ( $row - $_ >= 0 && $column + $_ < $dimension );
+        @chessboard[ $row + $_ ][ $column - $_ ][ $height ] = False if ( $row + $_ < $dimension && $column - $_ >= 0 );
+    }
+
+    @chessboard[ $row ][ $column ][ $height ] = 'QUEEN';
+}
+
+
+
+sub show-chessboard( @chessboard, $dimension ) {
+    for 0 ..^ $dimension -> $height {
+        say "Layer $height";
+
+        for 0 ..^ $dimension -> $row {
+            for 0 ..^ $dimension -> $column {
+                given @chessboard[ $row ][ $column ][ $height ] {
+                    when Str { print "\t ", @chessboard[ $row ][ $column ][ $height ]; }
+                    default  { print "\t  x  "; }
+                }
+
+            }
+
+            print "\n";
+        }
+    }
+}
+
+sub MAIN( Int $dimension = 3 ){
+    my $val = True;
+    my @chessboard = [[True xx $dimension] xx $dimension] xx $dimension;
+    
+    for 0 ..^ $dimension -> $height {
+        for 0 ..^ $dimension -> $row {
+            for 0 ..^ $dimension -> $column {
+    
+                # is the cell available?
+                next if ! @chessboard[ $row ][ $column ][ $height ];
+
+                # # place the queen
+                place-queen( @chessboard, $row, $column, $height, $dimension );
+            }
+        }
+    }
+
+
+    show-chessboard( @chessboard, $dimension );                
+}