Mathe Problem 1+2-3 ... +99-100

[ibp]

wie wäre es mit...

Delphi-Quellcode:

var i: integer; 
    e: extended;
begin 
  e := 1.0; 
  for i := 2 to 100 do
    e:=e+(power(-1,i)*i);

  Caption := floattostr(e); 
end;