zählen mit buchstaben?

[scp]

Na, dann so:

Delphi-Quellcode:

function LongPowerLong(ABaseNum, AExponent : Word) : LongWord;
var
  MultCount : Integer;
begin
  Result := 1;
  for MultCount := 1 to AExponent do
    Result := Result * ABaseNum;
end;

const
  AlphaBase = 26;
  AlphaMax  = 4;

function AlphaToNum(ATNstr : String  ) : LongWord;
const
  ValidChars : set of Char = ['A'..'Z'];
var
  ACount : Integer;

  function CharNum(CNchr : Char) : Byte;
    begin
      Case Ord(UpCase(CNchr)) Of
        65..90: CharNum := Ord(UpCase(CNchr)) - 65;
      end;
    end;
begin
  AlphaToNum := 0;
  for ACount := 1 to Min(length(ATNstr), AlphaMax+1) do
    begin
      If not (UpCase(ATNstr[ACount]) in ValidChars) then
        begin
          result := 0;
          Break;
        end;
      result := result + (CharNum(ATNstr[ACount]) * LongPowerLong(AlphaBase, Min(length(ATNstr), AlphaMax+1) - ACount));
    end;
end;

function NumToAlpha(NTAnum : LongWord  ) : String;
var
  NumChar  : array[0..AlphaBase-1] Of Char;
  NumCount : Word;
begin
  for NumCount :=  0 to (AlphaBase-1) do NumChar[NumCount] := Chr(65 + NumCount);

  // max 26 hoch (5-1)
  result := '';
  for NumCount := (AlphaMax+1) downto 1 do
    If (NTAnum < LongPowerLong(AlphaBase, NumCount)) then
      begin
        If not (NumCount = (AlphaMax+1)) then
          result := result + NumChar[NTAnum div LongPowerLong(AlphaBase, NumCount-1)];
        NTAnum := NTAnum mod LongPowerLong(AlphaBase, NumCount-1);
      end;

end;

Delphi-Quellcode:

var
  ATextFile : TextFile;
  bucount : LongWord;
begin
  AssignFile(ATextFile, 'C:\buchstab.txt');
  ReWrite(ATextFile);

  for bucount := AlphaToNum('AAAA') to AlphaToNum('ZZZZ') do
    WriteLn(ATextFile, NumToAlpha(bucount));

  CloseFile(ATextFile);
end;

Macht 456976 Möglichkeiten * 6 Bytes (#13#10 dabei) = 2741856 Bytes