On 2012-11-19, Dennis Lee Bieber <wlfr...@ix.netcom.com> wrote: > On Sun, 18 Nov 2012 17:52:35 -0800 (PST), su29090 > <129k...@gmail.com> declaimed the following in > gmane.comp.python.general: > >> >> I all of the other problems but I have issues with these: >> >> 1.Given a positive integer n , assign True to is_prime if n >> has no factors other than 1 and itself. (Remember, m is a >> factor of n if m divides n evenly.) >> > Google: Sieve of Eratosthenes (might be mis-spelled)
The sieve is a nice simple and fast algorithm, provided there's a bound on the highest n you need to check. It's much less simple and less fast if n is unbounded or the bound is unknown. Python's standard library isn't equipped with the an obvious collection to use to implement it either. >> 2.An arithmetic progression is a sequence of numbers in which >> the distance (or difference) between any two successive >> numbers if the same. This in the sequence 1, 3, 5, 7, ... , >> the distance is 2 while in the sequence 6, 12, 18, 24, ... , >> the distance is 6. >> >> Given the positive integer distance and the positive integer >> n , associate the variable sum with the sum of the elements >> of the arithmetic progression from 1 to n with distance >> distance . For example, if distance is 2 and n is 10 , >> then sum would be associated with 26 because 1+3+5+7+9 = >> 25 . > > So, what have you tried? > > Consider: you have a "sum", you have a sequence of "elements" > (based upon a spacing "distance"), and you have an upper bound > "n" > > You need to generate a sequence of "elements" starting at "1", > using "distance" as the spacing, until you exceed "n", and you > want to produce a "sum" of all those elements... This one's sort of a trick question, depending on your definition of "trick". The most obvious implementation is pretty good. In both cases a web search and a little high-density reading provides insights and examples for the OP. -- Neil Cerutti -- http://mail.python.org/mailman/listinfo/python-list