Solutions to Project Euler #10 (http://projecteuler.net/problem=10) "Find the sum of all the primes below two million"

primes_sum_twoM_pete.rb

def primes(num)
  ceiling = num
  number_set = 2.upto(ceiling).map(&:to_i)
  non_primes = {}

  number_set.each do |prime|
    next unless non_primes[prime].nil?

    number_set.each do |multiple|
      next_non_prime = (prime * multiple)
      break if next_non_prime > ceiling
      non_primes[next_non_prime] = false
    end
  end

  puts (number_set - non_primes.keys).inject(:+).to_s
end

def benchmark
  t1 = Time.now
  yield
  puts "#{Time.now - t1}"
end

num = 2_000_000
benchmark { primes(num) }

primes_sum_twoM_TRL.rb

def primesTRL(num)
  ceiling = num
  number_set = 2.upto(ceiling).map(&:to_i)
  non_primes = {}

  number_set.each do |prime|
    next unless non_primes[prime].nil?

    max_val = ceiling / prime
    break if max_val < prime

    prime.upto(max_val) do |multiple|
      next_non_prime = (prime * multiple)
      non_primes[next_non_prime] = false
    end
  end

  puts (number_set - non_primes.keys).inject(:+).to_s
end

def benchmark
  t1 = Time.now
  yield
  puts "#{Time.now - t1}"
end

num = 2_000_000
benchmark { primesTRL(num) }