Programming Exercise (HP-15C, 15C LE - and others)

[Gerson W. Barbosa]

(03-26-2014 06:20 PM)churichuro Wrote:  version for HP PRIME:

Code:


EXPORT TEST2()
BEGIN
  LOCAL suma,n;

  suma:= 0;
  FOR n FROM 10000 DOWNTO 1 DO
    suma:= suma + (1/n)*(-1)^(n+1);
  END;
  MSGBOX("Suma="+suma);
END;

result in about 1 sec !
Suma=.693097183059

Isn't "FOR n FROM 10000 DOWNTO 2 STEP -2 DO" a valid syntax in your UBASIC? If so, then the following would be worth trying. ¡Gracias!

Code:


1 T=TIME @ S=0 @ FOR N=10000 TO 2 STEP -2 @ S=S+1/(N-1)-1/N @ NEXT N @ DISP S;TIME-T

.69309718306 247.27

4 minutes and 7 seconds! (HP-71B)