hyuki/fib.rb Secret

## fib.rb
# cf. https://twitter.com/hyuki/status/1394478452854587394
FIB = {}

def fib(n)
  if FIB[n.to_s]
    return FIB[n.to_s]
  end
  if n <= 0 or n == 1
    v = 1.0
    FIB[n.to_s] = v
    return v
  else
    v = fib(n - 1) + fib(n - 2)
    FIB[n.to_s] = v
    return v
  end
end

K = Math::sqrt(6) * Math::PI / 3.0

def val(n)
  Math::exp(K * Math::sqrt(n))
end

1001.times do |n|
  printf("fib(#{n}) = %.0f\nval(#{n}) = %.0f\n\n", fib(n), val(n))
end
	# cf. https://twitter.com/hyuki/status/1394478452854587394
	FIB = {}

	def fib(n)
	if FIB[n.to_s]
	return FIB[n.to_s]
	end
	if n <= 0 or n == 1
	v = 1.0
	FIB[n.to_s] = v
	return v
	else
	v = fib(n - 1) + fib(n - 2)
	FIB[n.to_s] = v
	return v
	end
	end

	K = Math::sqrt(6) * Math::PI / 3.0

	def val(n)
	Math::exp(K * Math::sqrt(n))
	end

	1001.times do \|n\|
	printf("fib(#{n}) = %.0f\nval(#{n}) = %.0f\n\n", fib(n), val(n))
	end