請問: 『a的b次方 Mod n 』的程式該如何寫呢?謝謝!!

function AsquBmodN(a: Integer; b: Integer; N: Integer): Integer; var i: Integer; begin if (b>0) and (a>0) then Result := 1 else Result := 0; for i := 0 to b-1 do Result := Result * a; Result := Result mod N; end; //FYR

Hi may,    

procedure TForm1.Button3Click(Sender: TObject);
  function PowerAndMod(a,b,n : Integer) : Integer;
    Var
      Rest : Integer;
    begin
      try
        Rest := (Trunc(Power(a,b)) mod n);
      except
        Rest := 0;
      end;
      Result := Rest;
    end;
begin
  ShowMessage(IntToStr(PowerAndMod(2,10,10)));
end;

必須 Uses Math ---------------------------------- 小弟才疏學淺，若有謬誤尚請不吝指教 ----------------------------------

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Fishman