Data update

Task/Magic-squares-of-doubly-even-order/PascalABC.NET/magic-squares-of-doubly-even-order.pas

@@ -0,0 +1,29 @@
+const
+  n = 8;
+
+function MagicSquareDoublyEven(n: integer): array [,] of integer;
+begin
+  assert((n >= 4) and (n mod 4 = 0), 'base must be a positive multiple of 4');
+
+  // pattern of count-up vs count-down zones
+  var bits := Convert.ToInt32('1001011001101001', 2);
+  var size := n * n;
+  var mult := n div 4;  // how many multiples of 4
+
+  result := new integer[n, n];
+
+  var i := 0;
+  for var r := 0 to n - 1 do
+    for var c := 0 to n - 1 do
+    begin
+      var bitPos := c div mult + (r div mult) * 4;
+      result[r, c] := if (bits and (1 shl bitPos)) <> 0 then i + 1 else size - i;
+      i += 1;
+    end;
+end;
+
+begin
+  MagicSquareDoublyEven(n).Println;
+
+  Writeln(#10, 'Magic constant: ', (n * n + 1) * n div 2);
+end.