RPL exercise - Last Digits of Primes (HP 49G, G+, 50g)
06-01-2019, 05:44 AM
Post: #6
 Gerson W. Barbosa Senior Member Posts: 1,584 Joined: Dec 2013
RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g)
(06-01-2019 05:02 AM)DavidM Wrote:
(06-01-2019 04:43 AM)Gerson W. Barbosa Wrote:  Yes, 155.4 seconds (base 10), or 155.4 ms per prime, but that’s not linear. For 100 primes it takes 7.38 seconds or about 13.5 primes per second. Anyway, that’s an improvement over my first attempt. Hopefully there’s still a better way.

Here's a fairly brute-force method:

Code:
\<<    0. 9. NDUPN \->ARRY    5    ROT    1 SWAP START       NEXTPRIME       SWAP OVER       I\->R 10. MOD       DUP2       GET 1. + PUT       SWAP    NEXT    DROP    DUP 1. GET SWAP    DUP 3. GET SWAP    DUP 7. GET SWAP    9. GET    4. \->LIST \>>

The result for an input of 1000. is { 245. 253. 256. 246. }, and on my 50g takes about 41s to complete. Note that I'm using approximate numbers here instead of exact to shorten the time a bit.

Very nice!

53.3 seconds even using exact numbers. '155.4/41' = 3.79, this ratio used to be about 10 (that is, my programs used to take 10 times as much, compared to the optimal ones by Valentin and others).

I’ve used a somewhat unorthodox method which surely doesn’t obey the “KISS” rule. Also, my program is about 50% longer.
 « Next Oldest | Next Newest »

 Messages In This Thread RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019, 03:07 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Valentin Albillo - 06-01-2019, 04:13 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019, 04:43 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - DavidM - 06-01-2019, 05:02 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gilles - 06-01-2019, 05:29 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Albert Chan - 06-01-2019, 12:42 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019 05:44 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Carsen - 06-01-2019, 08:51 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - grsbanks - 06-01-2019, 12:48 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Valentin Albillo - 06-01-2019, 02:38 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019, 03:29 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Valentin Albillo - 06-01-2019, 09:59 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-02-2019, 10:43 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Valentin Albillo - 06-02-2019, 11:27 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-03-2019, 12:14 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Valentin Albillo - 06-03-2019, 04:25 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019, 03:17 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019, 03:41 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - DavidM - 06-01-2019, 04:08 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-01-2019, 09:11 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Dave Britten - 06-01-2019, 11:05 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-02-2019, 06:10 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - John Keith - 06-02-2019, 04:39 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gilles - 06-02-2019, 09:18 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Carsen - 06-03-2019, 03:49 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-03-2019, 01:08 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Carsen - 06-03-2019, 08:15 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - Gerson W. Barbosa - 06-04-2019, 03:00 AM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - fred_76 - 06-04-2019, 02:21 PM RE: RPL exercise - Last Digits of Primes (HP 49G, G+, 50g) - ttw - 06-04-2019, 05:09 PM