euler 10

gistfile1.txt

def summation_of_primes(max)
  array_of_nums = (0...max).to_a
  array_of_nums[0] = nil
  array_of_nums[1] = nil
  #skip index 1 as thats number 1 and don't want to add that in later, 0 by default wont be added in
  prod = 1
  array_of_nums.each do |num|
    next if num == nil
    until prod > max
      (2..max).each do |mult|
        prod = num * mult
        array_of_nums[prod] = nil
      end
    end
  end

  p array_of_nums.compact.inject(&:+)
end

summation_of_primes(2000000)
#1000000000001