Data commit

Task/Gray-code/Delphi/gray-code.delphi

@@ -0,0 +1,45 @@
+program GrayCode;
+
+{$APPTYPE CONSOLE}
+
+uses SysUtils;
+
+function Encode(v: Integer): Integer;
+begin
+  Result := v xor (v shr 1);
+end;
+
+function Decode(v: Integer): Integer;
+begin
+  Result := 0;
+  while v > 0 do
+  begin
+    Result := Result xor v;
+    v := v shr 1;
+  end;
+end;
+
+function IntToBin(aValue: LongInt; aDigits: Integer): string;
+begin
+  Result := StringOfChar('0', aDigits);
+  while aValue > 0 do
+  begin
+    if (aValue and 1) = 1 then
+      Result[aDigits] := '1';
+    Dec(aDigits);
+    aValue := aValue shr 1;
+  end;
+end;
+
+var
+  i, g, d: Integer;
+begin
+  Writeln('decimal  binary   gray    decoded');
+
+  for i := 0 to 31 do
+  begin
+    g := Encode(i);
+    d := Decode(g);
+    Writeln(Format('  %2d     %s   %s   %s  %2d', [i, IntToBin(i, 5), IntToBin(g, 5), IntToBin(d, 5), d]));
+  end;
+end.