Talk:Primes - allocate descendants to their ancestors: Difference between revisions
Talk:Primes - allocate descendants to their ancestors (view source)
Revision as of 02:53, 26 February 2015
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# I already put a textual description : "This solution could be compared to the solution that would use the decomposition into primes for all the numbers between 5 and 3^33".
--[[User:Old man|Old man]] ([[User talk:Old man|talk]]) 09:00, 25 February 2015 (UTC)
== Task is ambiguous ==
I would like to see some ambiguities resolved, here:
(1) Timing. Timing is meaningless because of potential differences between machines. (Imagine I use elastic map reduce here, for example.) See also [[Rosetta_Code:Village_Pump/Run_times_on_examples%3F]]
(2) Inadequate illustration: So, ok, an ancestor is the sum of the factors of a prime. But the example only considers a case where there are two factors. What are the ancestors of 72? When we are summing ancestors, if a number is an ancestor of two other numbers do we count it once or twice? And so on...
(3) Inadequate definition: What is a descendant? Clearly there are some bounds on descendants from the problem writeup stating that 46 has 557 descendants, but what are they?
Hypothetically, this part of the "C implementation" might define the bounds of the problem:
<lang C>#define MAXPRIME 99 // greatest prime factor
#define MAXPARENT 99 // greatest parent number
#define NBRPRIMES 30 // max number of prime factors
#define NBRANCESTORS 10 // max number of parent's ancestors</lang>
But there might be additional constraints implemented in the algorithm and/or data structures. This kind of thing really belongs in the task description.
Hypothetically, I might try inspecting some of the code samples, to see how they behave. But, for example, the C implementation does not compile. Among its problems is that it tries to do <code>malloc(sizeof(Children))</code> when what has been defined is struct Children.
(I am rather reluctant to attempt to debug someone else's buggy code to attempt to reverse engineer the bounds of the problem when I could more easily ask for those bounds.)
So... would it be possible to rephrase the task to address these issues? --[[User:Rdm|Rdm]] ([[User talk:Rdm|talk]]) 02:53, 26 February 2015 (UTC)
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