[VA] Short & Sweet Math Challenges #23: "May the 4th Be With You !" Special

[Valentin Albillo]

 
Hi, Bob !

(05-10-2018 10:56 PM)rprosperi Wrote:  Thanks for these painstakingly detailed notes about your solutions; these are always enjoyable even I've not had time, or sometimes the skills, to tackle them. I particularly like your use of "Lessons learned" to highlight the key techniques used for each solution, this helps a lot to drive these points in.

Certainly these challenges I concoct do take a lot of time, first for getting a workable idea, then to find my own solutions to it, and finally to write, proofread and format the looong posts (the one for the challenge proper and the one for the solutions).

I recently added the feature you mention and I'm glad you like it. Though not a teacher by trade, I'm pretty fond of sharing knowledge with others, which can be considered kind of "teaching".

Quote:I had no idea one could apply the substring operator (I like 'slicer' better) multiple times. Though it appears to not be documented it does make sense following the 71b's syntax, etc. Very clever!

I knew about the "slicer" many decades ago, back in the very early 80's, where I saw it available in HP-85's BASIC. There, it could be applied only to string variables or elements of a string array but not to string expressions, and only once. The HP-71B's BASIC version is much enhanced over the HP-85's one and can be applied also to string expressions and any number of times in sequence.

In the first challenge I use it to save bytes, because [20-VAL(DISP$)][1,1] is shorter than other ways of achieving the same result with a single slicing operation.

Quote:Thanks for another set of interesting and educational challenges. I suspect all the drama taking place in parallel distracted folks from playing along.

Thanks to you for your continued appreciation and for letting me know, it means a lot to me to ascertain that my efforts didn't go to waste.

Have a nice weekend and best regards.
V.