Shannon wrote:
An integer is said to be prime if it is divisible by only 1 and
itself. For example, 2, 3, 5 and 7 are prime, but 4, 6, 8 and 9 are
not.
a) Write a function that determines whether a number is prime.
b) Use this function in a program that determines and prints all the
prime numbers between 2 and 10,000. How many of these numbers do you
really have to test before being sure that you have found all the
primes?
c) Initially, you might think that n/2 is the upper limit for which
you must test to see whether a number is prime, but you need only go
as high as the square root of n. Why? Rewrite the program, and run it
both ways. Estimate the performance improvement.
Do your own homework!
--
Regards,
Mike Fry
Johannesburg.
