(DM42) Lottery number generator programming
02-11-2019, 07:35 PM (This post was last modified: 02-11-2019 07:45 PM by Dieter.)
Post: #2
 Dieter Senior Member Posts: 2,397 Joined: Dec 2013
RE: (DM42) Lottery number generator programming
(02-10-2019 09:54 AM)psw Wrote:  I am a sheer beginner of DM42 programming and interesting in a simple and useful program.
...
How you combine or improve these, I only know a little about 8-bit BASIC.
Thank you for reading and I look forward to hearing your great help.

I see this is your first post here, so welcome to the forum.

Regarding the intended program, I think we have to start from scratch here. There seem to be several misconceptions about various DM-42 (or Free42, or HP-42s) commands. For instance it is not a good idea at all to seed the random number generator before every single RAN call. Essentially you can forget about SEED unless you want to reproduce a certain random number sequence. Also your code would not generate integers between 1 and 18 but between 0 and 17 – you have to add 1 here. Then there are loop counters DSE and ISG so that manually decrementing R00 and checking whether it is > 0 or not is not required. This works like a FOR-loop in other programming languages. Finally ASTO does not store a value into Alpha, but it stores the first six characters of Alpha into the specified register (that's why the command then reads ASTO 03 or ASTO ST X or whatever). So the code snippets you posted will not work, neither separately nor combined.

OK, let's forget about all this. The program you want would have to behave like this:

Code:
Generate X random integers between 1 and Y Do the following loop X times    Generate a random integer R between 1 and Y    If this is the first loop, skip the following test       For all previous random integers          Check if R equals one of these          If it does, jump back to the main loop and generate a new random integer          Proceed to next previously calculated random integer       End of test loop    At this point no match has occured, so save R in the result list    Append R to the output string End of main loop Display output string

The following Free42 program implements this algorithm. The max. random integer Y is stored in "MAX", flag 01 is used to mark the first loop, it is automatically cleared when tested, and the loops are controlled by ISG and DSE. The loop counter is in R00, the test loop counter is on the stack. The random integers are stored in R01, R02, R03 etc. If, say, the 4th number has been calculated, the program compares this to R03, R02 and R01 to see whether there are duplicates. If there are, a new number is calculated. If not, the new R is stored in the respective register, here R04. The first two lines correct input errors ("18 different numbers out of 4" instead of vice versa) and the final lines restore the original Y and X and remove "MAX" (cleanup). This way you can repeat the whole thing by simply pressing [R/S].

This program can be optimized. For instance the whole flag thing can be removed. ;-) But it is more clear this way. Now take a look at the program and ask everything you don't understand.

Code:
00 { 90-Byte Prgm } 01>LBL "RANDOM" 02 X>Y? 03 X<>Y 04 1E3 05 ÷ 06 1 07 + 08 STO 00 09 Rv 10 STO "MAX" 11 SF 01 12 CLA 13>LBL 01 14 RCL 00 15 IP 16 1 17 - 18 RAN 19 RCL× "MAX" 20 IP 21 1 22 + 23 FS?C 01 24 GTO 03 25>LBL 02 26 RCL IND ST Y 27 X=Y? 28 GTO 01 29 Rv 30 DSE ST Y 31 GTO 02 32>LBL 03 33 STO IND 00 34 |-" " 35 AIP 36 ISG 00 37 GTO 01 38 RCL "MAX" 39 RCL 00 40 IP 41 1 42 - 43 CLV "MAX" 44 AVIEW 45 END

Note: "Rv" means R↓ and line 34 appends a space to Alpha.

The following example was obtained after 0,12345 [SEED] on Free42. But I can't say if this will produce the same numbers on the DM-42.

18 [ENTER] 4 XEQ"RANDOM"
4 7 3 16
[R/S]
9 6 17 4
[R/S]
3 16 4 18

etc.