Sha256: 3fcfcca860a04410a918c52b7325a8abf4ecfa58c404c636d4e4a4bfcd316aaa
Contents?: true
Size: 993 Bytes
Versions: 174
Compression:
Stored size: 993 Bytes
Contents
The Sieve of Eratosthenes is a simple, ancient algorithm for finding all prime numbers up to any given limit. It does so by iteratively marking as composite (i.e. not prime) the multiples of each prime, starting with the multiples of 2. Create your range, starting at two and continuing up to and including the given limit. (i.e. [2, limit]) The algorithm consists of repeating the following over and over: - take the next available unmarked number in your list (it is prime) - mark all the multiples of that number (they are not prime) Repeat until you have processed each number in your range. When the algorithm terminates, all the numbers in the list that have not been marked are prime. The wikipedia article has a useful graphic that explains the algorithm: https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes Notice that this is a very specific algorithm, and the tests don't check that you've implemented the algorithm, only that you've come up with the correct list of primes.
Version data entries
174 entries across 174 versions & 1 rubygems