Primfaktorzerlegung läuft viel zu langsam...

[Chris P]

So habe ich das gelöst:

Delphi-Quellcode:

function IsPrime(const Value: Cardinal): Boolean;
var
   t: Cardinal;
begin
   if (Value = 2) then
   begin
      Result := TRUE;
      Exit;
   end;

   if (Value < 2) or (Value mod 2 = 0) then
   begin
      Result := FALSE;
      Exit;
   end;

   t := 3;
   while (t * t <= Value) do
   begin
      if (Value mod t = 0) then
      begin
         Result := FALSE;
         Exit;
      end
      else
         t := t + 2;
   end;
   Result := TRUE;
end;
// -----------------------------------------------------------------------------
function Factorize(const V: Cardinal): TFactors;
var
   t, x, Count: Cardinal;
begin
   t := 2;
   x := V;

   Count := 0;
   SetLength(Result, 0);

   while (t <= x) do
   begin
      if (x mod t = 0) then
      begin
         Count := Count + 1;
         SetLength(Result, Count);
         Result[Count - 1] := t;
         x := x div t;
         t := 2;
      end
      else
         t := t + 1;
   end;
end;