Talk:Pollard's rho algorithm

message: The algorithm under "Richard Brent's Variant" appears to have some problems. One problem is that 'm' is used but doesn't seem to be initialized. Where does it come from?
It states that 'm' is passed as input to the algorithm, such that 'm' > 0.
Patrickkonsor (talk) 14:56, 17 May 2008 (UTC)

message: The algorithm presented here is /not/ faster than the original algorithm when implemented as presented. Can anyone show an implementation that actually is faster? Many books and docs say that it is faster but there is no substantiation... I would guess that it came from some old source and has been repeated over and over without being checked. A simple direct copy of the algorithms here into C++ leaves the Brent variant looking pointless...
Has anyone actually gotten this to be faster than the vanilla rho algorithm?
Jheriko (talk) 16:48, 2 January 2008 (UTC)
thread_title:  Brent's algorithm 

message: I don't think the algorithm will work with any pseudo-random sequence, as perhaps implied by this article.  The pseudo-random sequence must have the property that f(x) mod p = f(x mod p) mod p, for any x and p, so that collisions in modulo-p space behave as expected.
Am I right?  It's a while since I've done this kind of stuff in earnest.  —Preceding unsigned comment added by G121 (talk • contribs) 13:28, 4 July 2008 (UTC)
thread_title:  pseudo-random sequence 

message: Supposed Pollard's Rho Algorithm, Richard Brent Variant: Since (q) is always MOD (n), (g) can never equal (n) -- making steps 4 and 5 pointless. I have seen several Java implementation which mindlessly do with exact some thing! Still looking for the correct algorithm... bitRAKE (talk) 15:23, 11 July 2008 (UTC)
thread_title:  Confusing Algorithm 

message: While it's true that two numbers x and y are congruent modulo p with probability 0.5 after 1.177\sqrt{p} numbers have been randomly chosen, we still need a method to find such a pair without trying all the pairs. This relies on a property of f(), i.e., f(x)=f(y) \mod p when x=y \mod p.
143.117.38.239 (talk) 10:59, 11 September 2009 (UTC)
thread_title:  one key point is missing from the Core Idea section 

message: The article uses O(n1/4 polylog(n)) as the number of steps required to find a factor on a semiprime number, but polylog almost always gives imaginary or negative results -  - is there a correct formula? Nightgunner5 (talk) 00:09, 10 June 2010 (UTC)
replies: text: Just adding my own two cents, I notice that also the order of the polylogarithm is not specified. I think I'll add a “citation needed” tag to the article. Hanche (talk) 06:28, 8 October 2010 (UTC)
thread_title:  Complexity 

message: I made an attempt to update the article with a reference to the third edition of the CLRS test "Introduction to Algorithms" as well as post some working POSIX compliant C code but the editor is too complex and I don't see how to add anything to this article that would be readable. I am not about to spend a day learning how to add a simple reference or format fixed text code to a page. I can certainly add it in and then hope someone else cleans it up.
blastwave (talk) 22:00, 6 December 2015 (UTC)
replies: text: The reference you added looks reasonably formatted — thanks. I'm not convinced that this is a good place to add complete implementations, though — Wikipedia isn't really set up to work well as a code repository, and should be more about the idea of an algorithm than the details of coding it. Re your difficulty with the editor: are you using the GUI "Visual Editor", or the text editor for wiki-markup? You can change between the two in your preferences (the checkbox "Temporarily disable the visual editor while it is in beta" under "Editor" in the "Editing" tab); the Visual Editor is intended to be easier to use but I prefer the text editor. —David Eppstein (talk) 22:37, 6 December 2015 (UTC)
thread_title:  attempted to update article 

message: I found the article rather confusing, perhaps due to edits from multiple sources based on different variants of the algorithms.  Here are something I want to see fixed:
* The algorithm shown does not match the example (2 -> 5 -> 26 -> 677 -> 871), or the explanation in the text.  The algorithm in text uses the Floyd cycle detection algorithm, the the example and the explanation do not.  Also, the 871 number seems to pop from nowhere.
* Since the text does not use Floyd cycle detection, it would appear that the algorithm will only work if the cycle is of length 1, which would completely nullify the benefit of the birthday paradox.
* The usage of the birthday paradox is not explained, which is crucial to the understanding of the algorithm.  Uninteresting details, like the constant in the birthday paradox, is added for no reason.
* No explanation is given to the Floyd cycle detection algorithm.  Readers with no previous knowledge of that algorithm would found the article impossible to digest.
* The name "rho algorithm" is explained twice in the article, for no obvious reason.
* The text "The randomizing function g(x) must be a polynomial modulo n, so that it will work both modulo p and modulo n. That is, so that g(x mod p) ≡ g(x) (mod p)." appear at the wrong place: instead of preparing the readers to understand why the algorithm work, it looks more like an afterthought.
I'd like to write an edit to fix these problems.  Let me know if you don't like it.
Isaacto (talk) 01:09, 28 June 2017 (UTC)
replies: text: I think you have good points.  Bubba73 You talkin' to me? 01:51, 28 June 2017 (UTC)
thread_title:  Some points of confusion