RosettaCodeData/Task/Fibonacci-sequence/Ruby/fibonacci-sequence-8.rb
Ingy döt Net db842d013d A-M baby
2013-04-10 21:29:02 -07:00

4 lines
102 B
Ruby

def fib
phi = (1 + Math.sqrt(5)) / 2
((phi**self - (-1 / phi)**self) / Math.sqrt(5)).to_i
end