Prime::EratosthenesSieve

Internal use. An implementation of eratosthenes’ sieve

Public Class Methods

new()

 
               # File prime.rb, line 425
def initialize
  @primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101]
  # @max_checked must be an even number
  @max_checked = @primes.last + 1
end

Public Instance Methods

get_nth_prime(n)

 
               # File prime.rb, line 431
def get_nth_prime(n)
  compute_primes while @primes.size <= n
  @primes[n]
end