20/11/16 03:31:51.13 apQPm4KR.net
>>965
haskell
import Data.List
str = "曇,晴,曇,曇,晴,曇,曇,雨,雨,雨,曇,曇,晴,曇,雨,曇,雨,曇,曇,曇,晴,曇,雨,晴,晴,晴,晴,曇,晴,曇,晴"
accuracy x = let
pairs = id
. map ( take 2 . reverse ) -- [ "BA", "CB", "DC",..]
. drop 2 -- [ "AB", "ABC",..]
. inits -- [ "", "A", "AB",..]
. filter ( /= ',' ) -- "ABCD.."
$ x
successes = filter ( \x -> head x == last x ) pairs
nP = genericLength pairs
nS = genericLength successes
in nS / nP
main = print $ accuracy str