scramble prime challenge

[Don Shepherd]

(02-14-2020 10:09 PM)John Keith Wrote:  Here is a brute-force HP49/50 program using ListExt commands. DIFF is the 4th program in this post. It is a faster version of the GoferLists command Diff, which is set difference or complement.

This program does not check for 2 or 5 but it does check for ineligible digits.

Code:


Spoilers...










\<< I\->NL DUP { 1. 3. 7. 9. } DIFF
  IF SIZE
  THEN DROP 0.
  ELSE DUP SIZE
    \<< NL\->I ISPRIME?
    \>> DOPERM 0. POS NOT
  END
\>>

thanks John.

What exactly does this program do, I'm not familiar with RPL.
Don