18/11/05 23:33:04.48 6d8cBeMO.net
>>215 Ruby
require 'matrix'
def hoge(a, b, c)
rm, fm, im = Matrix[[1, 1], [1, 0]], Matrix[[1, 0], [0, 1]], Matrix[[b], [a]]
(0..Float::INFINITY).each do |n|
m = fm * im
return m[1, 0] > c ? false : n if m[1, 0] >= c
fm *= rm
end
end
p hoge(0,1,88) #=> false
p hoge(0,1,89) #=> 11
p hoge(0,1,90) #=> false