(04-23-2019 04:59 PM)Albert Chan Wrote:  sb_find(), version 6. Switched to Python to extend search range.
As expected, Python code is even shorter.

(03-21-2019 02:08 AM)Valentin Albillo Wrote:   
Rules:
[list]
[*]Using anything other than a physical or emulated HP calculator is strictly disallowed. Also no VBA, Excel. Pascal, C/C#/C++, Java, Python, Haskell, etc. code, please go elsewhere for that. You must write your code in a language supported in some HP calc (i.e.: RPN, RPL, 71B BASIC/FORTH, etc).

(04-20-2019 10:47 AM)Bernd Grubert Wrote:  Here is my solution to Tier 2. It is 192 bytes long, due to the lack of prime number checking and the remainder function on the HP-15C. [...] I have done the test runs on the HP-15C emulator on a PC, since the processing time on my DM-15L is far too long... Since the largest integer number the HP-15C can exactly represent is 9,999,999,999. , this implementation of the Miller-Rabin algorithm can check only number up to 99,999. Due to memory limitations, on the real HP-15C and the DM 15L the longest sequence is 26 values. [...] For base 31 I got the sequence: 619, 18257, ...,(I stopped at 34139 after ~90 min., because I didn't want to wait any longer) [...] For base 7 I got the sequence: 4801, ...,(I stopped at 23451 after ~60 min.) [...] I have attached an HTML-documentation and a txt-file, that can be read into the emulator after changing the extension back to ".15c"

(04-21-2019 07:06 AM)Gilles Wrote:  Tier 1: Here is my solution without reading others responses. I image that there exists better way. This one is "bestial" ;D Always impressed how fast NewRPL is. Brutal force :

1/ HP50g NewRPL or RPL [...] Solved in only 1.3s in newRPL (on my PC) , 116s with HP50g hdw, much much slower in 779s in RPL (on my PC with Emu48). NewRPL 600 times faster in this case on a PC. [...] 2/ HP50g RPL with ListExt, shorter but slower [...]

(04-24-2019 05:36 AM)Massimo Gnerucci Wrote:  

(04-23-2019 04:59 PM)Albert Chan Wrote:  Switched to Python to extend search range. As expected, Python code is even shorter.

Hi Albert, really interesting (and a little beyond my skills), as usual, but wasn't this one of Valentin's rules?

(03-21-2019 02:08 AM)Valentin Albillo Wrote:  Using anything other than a physical or emulated HP calculator is strictly disallowed. Also no VBA, Excel. Pascal, C/C#/C++, Java, Python, Haskell, etc. code, please go elsewhere for that. You must write your code in a language supported in some HP calc (i.e.: RPN, RPL, 71B BASIC/FORTH, etc).

• The purpose of my challenges is to offer HP-fan fellow readers the opportunity to actually get to use their HP calculators and their languages to solve allegedly interesting math topics, so that perhaps we all learn some new exciting math facts and some worthwhile HP-calc programming techniques which are cleverly used to overcome the natural limitations of our beloved HP calcs and their languages. Nothing more and nothing else.

• No HP calcs/languages are used at all, which completely defeats the intended purpose.
   
• No HP calcs/languages limitations are overcome at all, with was the idea, as the challenges' difficulty is geared to HP calc/languages, not to Mathematica/Lua/Python running on a PC where the difficulty and inconvenience are diminished by orders of magnitude, which amounts to shameful cheating.
   
• No HP calcs/languages' new interesting programming techniques are created for everyone to learn, which again completely defeats the intended purpose.
  

• Utter disrespect to the rules I explicitly stated, which aren't arbitrary but do have the explicit intended purposes stated above.
   
• Shameful cheating, as he is using software/harware orders of magnitude more powerful that the intended one, namely HP calcs/languages.
   
• Spoiling, as he gives lots of versions and explicit solutions with no "spoilers" warnings whatsoever, thus spoiling the fun for any rule-abiding forum readers, and probably discouraging them from even attempting the challenge using their HP calculators.
   
• Trolling, as he has done this any number of times by now. He did that with my cin(x) challenge, for example, and with all the recent ones. He does it all the time though he could certainly go on and post his Mathematica/Lua/Python code in Mathematica/Lua/Python forums (as he did with my Cin(x) challenge; but he nevertheless posted his Lua or Python code here as well).

Valentin Albillo Wrote:Hi, Albert Chan:

Your second attempt at Tier 2 is essentially correct but for a minor detail. You posted (for base 7):

lua> sb_find(7)
7     1 <<<<<<<<<<<<<<<
4801     25
201683     35
16470859     49
115296019     55

but your first result above (7 1) is incorrect because 1 is neither a prime nor a composite, it's a unit. Not being a composite, as asked, makes it an invalid result which perhaps you might want to correct in your post before I post my solutions.

Thanks for your interest and your clear & concise solutions, best regards.
V.
.

Quote:10 INPUT "BASE ?"; B
20 INPUT "DIGITS ?"; N
30 DIM S(N),L(N),H(N)
40 INPUT "SB VALUE ?"; S(N)
50 I = N
60 GOSUB 100
70 END

100 L(I) = S(I)-(B-1)*(I-1)
110 IF L(I) < 0 THEN L(I) = 0
120 H(I) = S(I)
130 IF H(I) >= B THEN H(I) = B-1

150 IF L(I) > H(I) THEN RETURN
160 IF I = 1 THEN GOTO 200
170 S(I-1) = S(I)-L(I)
180 I = I-1 @ GOSUB 100 @ I = I+1
190 L(I) = L(I)+1 @ GOTO 150

200 T = 0
210 FOR K = N TO 1 STEP -1
220 T = T*B+L(K)
230 NEXT K
240 PRINT T;

250 INPUT "MORE?";Y
260 IF Y<>0 THEN RETURN

(04-26-2019 06:13 PM)Albert Chan Wrote:  I did downloaded the Emu71/Windows, but unable to get the code fully worked out.

BTW, where to get ISPRIME() (or equivalent) for the HP-71B emulator ?

(03-28-2019 12:38 AM)Valentin Albillo Wrote:  Tier 1 - The Challenge:
(...)

Also, being a 10-digit number and having all its digits distinct means that its digits are 0, 1, 2, 3, ... , 9 in some order and thus their sum is 1 + 2 + 3 + ... + 9 = 45, which is divisible by 9 so each Homage number has to be divisible by 9 too. As 9 is coprime to 41 and 271, each Homage number N must be divisible by their product, i.e., by 41 * 271 * 9 = 99,999.
 

Quote:10 ON ERROR GOTO 190
20 INPUT "BASE?";B
30 N=CEIL(12/LOG10(B)) @ DIM S(N),L(N),H(N)
40 FOR C=4 TO (B-1)*N
50 IF GCD(C,B-1)=1 AND FPRIM(C,C)=0 THEN
60 T=0 @ I=N @ S(I)=C @ GOSUB 100 @ PRINT C;T
70 END IF
80 NEXT C
90 END

100 L(I)=MAX(S(I)-(B-1)*(I-1), 0)
110 H(I)=MIN(S(I), B-1)
120 IF L(I)>H(I) OR T THEN RETURN
130 IF I=1 THEN GOTO 170
140 S(I-1)=S(I)-L(I)
150 I=I-1 @ GOSUB 100 @ I=I+1
160 L(I)=L(I)+1 @ GOTO 120

170 FOR K=N TO 1 STEP -1 @ T=T*B+L(K) @ NEXT K
180 T=FPRIM(T,T) @ RETURN
190 T=-T @ RETURN