happy_primes.rb

def is_prime?(n)
  if n == 1 || n == 2 || n == 3
    return true 
  end
  
  counter = 4
  
  while counter < n do 
    if n % counter == 0 
      return false
    end
    counter += 1
  end
  return true
end

def is_happy?(n)
  p "is happy #{n}"
  processed_nums = {}
  sum = 0 
  response = square_and_sum(n)
  while !processed_nums[response] do 
    if response == true 
      return true
    else
      processed_nums[response] = true 
      response = square_and_sum(response)
    end
  end
  return false 
end

def square_and_sum(n)
  sum = 0
  n.to_s.split("").each do |i|
    sum += (i.to_i * i.to_i)
  end
  if sum == 1
    return true 
  else
    return sum
  end
end

def happy_primes(start_from, end_at)
  all_happy_primes = []
  n = end_at - start_from
  n.times do |num|
    num = num + start_from + 1
    if num == 0
      next
    end
    if is_prime?(num)
      if is_happy?(num)
        all_happy_primes << num
      end
    end
  end
  return all_happy_primes
end

p happy_primes(0,50)