4 lines
127 B
Ruby
4 lines
127 B
Ruby
def fib(n)
|
|
raise RangeError, "fib of negative" if n < 0
|
|
(fib2 = proc { |m| m < 2 ? m : fib2[m - 1] + fib2[m - 2] })[n]
|
|
end
|