PRIME5 and PRIME4xx bug!
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PRIME5 and PRIME4xx bug!
Just wanted to announce that a semi-serious bug has been discovered in all
versions of STL's TI-85 Basic factoring program PRIME4, and all its succeeding
versions. Every PRIME4xx program has the bug. However, PRIME2 did not. After
some searching, I found the solution, and have now fixed it. The fixed version,
PRIME5, will now correctly identify all prime numbers as prime, and find the
smallest prime factor for all composite numbers. (Try factoring 341*6661 on
PRIME4xx). The bugfix involved increasing its size by 40something bytes, and a
speed decrease of around 10%. However, PRIME5 is still faster than PRIME2, and
faster than every other program out there for the TI-85... (It takes 7 minutes
flat on my standard test number 55511*314159). So...
The current list provided with PRIME4xx, NTILDE, is *not* valid anymore. (With
previous versions, it did not have to be updated). PRIME5 will only work with
the new NTILDE list. Also, two new versions of PRIME5 will be released
simultaneously: PRIME5B and PRIME5D. PRIME5B will be just as fast as the
original PRIME4 (without PRIME4's bug) but at a cost of ~200 bytes. PRIME5D,
unlike ANY OTHER PROGRAM for the TI-85, will allow the factoring/primality
proving work of PRIME5 to be spread over many TI-85s. At a cost of about ~60
bytes. Thus if you and two friends all get PRIME5D on your TI-85s, primality
testing can be completed in 1/3 the time! All PRIME5x programs will work with
the updated list. All I have to do is finalize the programs, get them on my
computer, and write some new documentation. (Yes, that documentation is growing
BIG by now.) Expect PRIME5 to be out in the next week or so, depending on how
much free time I have.
Thanks to Vapor256@aol.com for finding this bug so I could squash its brains
out. :-D
STL
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