17/07/24 19:10:35.21 nJVItCRy.net
>>411 Ruby
def farey_sequence(n)
(1..n-1).map{|i| 1r*i/n}
end
def ans_411(m)
(2..m).map{|i| farey_sequence(i)}.flatten.uniq.sort
end
ans_411 3 #=> [(1/3), (1/2), (2/3)]
ans_411 5 #=> [(1/5), (1/4), (1/3), (2/5), (1/2), (3/5), (2/3), (3/4), (4/5)]