approximate_pi.rb

def pi(num)
  sum = 3
  (1..num).each do |n|
    dn = n*2
    puts "(4.0/(#{dn} * #{(dn+1)} * #{(dn+2)}) * (#{(-1)**(n+1)}))"
    sum += (4.0/(dn * (dn+1) * (dn+2)) * ((-1)**(n+1)))
  end
  return sum
end

def divider(num, divide)
  if (num != 0)
    print((num/divide).floor)
    left = (num%divide) * 10
    sleep(1)
    divider(left, divide)
  end
end

def divider_arr(num, divide, arr, time)
  if (num != 0 && time < 5000)
    arr << (num/divide).floor
    left = (num%divide) * 10
    time += 1
    return divider(left, divide, arr, time)
  end
  return arr
end


def plus_arr(arr1,arr2)
  bigarr_size = arr1.size() > arr2.size() ? arr1.size() : arr2.size()
  ans = Array.new(bigarr_size, 0)
  (0..bigarr_size-1).each do |d|
    val1 = d >= arr1.size() ? 0 : arr1[d]
    val2 = d >= arr2.size() ? 0 : arr2[d]
    if d > 0
      if ans[d] + val1 + val2 > 10
        ans[d-1] += 1
        ans[d] = (ans[d] + val1 + val2)%10
      else
        ans[d] += val1 + val2
      end
    else
      ans[d] += val1 + val2
    end
  end
  return ans
end