Faster factor finder method for 42S

[Dave Britten]

(11-29-2019 09:38 AM)Csaba Tizedes Wrote:  

(11-26-2019 04:24 PM)Dave Britten Wrote:  undocumented matrix function [MIN]
I got the idea from a TI-84 factor finder

Nice, could you post a link or something about this MIN function and the TI-84 factor finder program?

Thanks,
Csaba

There are sooo many factoring programs for the 83/84 floating around that I honestly couldn't tell you where I found it. Here's the code, though. It also does some clever tricks with End, so it's a bit tough to follow.

Code:

Input "X=",X
0→dim(⌊FACTR
2→D
For(B,2,6
While B<Xnot(fPart(X/B
Lbl 1
max(B,D→D
While fPart(X/D
D+2→D
End
X/D→X
Disp D
D→⌊FACTR(dim(⌊FACTR)+1
End
End
For(C,B,√(X),30)
If min(fPart(X/(C+{0,4,6,10,12,16,22,24
End
If C²≤X
Then
C→B
X→C
Goto 1
End
X→⌊FACTR(dim(⌊FACTR)+1
⌊FACTR

For info on the "[MIN]" function (yes, the brackets are included in the function name), see Joe's post linked above.