More a curiosity than a challenge...

[Vieira, Luiz C. (Brazil)]

Hi;

One curiosity (or chalenge): given three numbers A, B and C in the stack (X-, Y- and Z- registers) what's the shortest way to get (A+B+C), A, B and C in any order in the stack by using only the stack registers and stack manipulations?

Before   After  or     or    or...

X  A     A      A+B+C  A

Y  B     B      A      A+B+C

Z  C     C      B      -

T  -     A+B+C  -      C

L  -     -      C      B

I know an easy way with the HP42S:

ENTER

RCL - ST Z

RCL - ST T

or in an HP41:

ENTER

R^  (ROLL-UP)

ST+ Y

R^  (ROLL-UP)

ST+ Z

but I would like to know the shortest way to do it in, say, a Voyager, or in an HP32SII, or in an HP12C. Restrictions are the calculator's resources themselves. Any clues?

This is intented to activate some stand-by, RPN-mode, stack-simulation areas of contributors' brains. And, of course, I want to know a better, shortest way to do it.

Hope you like it.

Luiz C. Vieira - Brazil

[Vieira, Luiz C. (Brazil)]

Hi;

the HP42S procedure is:

ENTER

RCL + ST Z

RCL + ST T

Forgive me!

Luiz C. Vieira - Brazil