Question

在整理一些算法问题的同时,我还利用了这些功能。

Maps a list of functions to one value:

mapX :: a -> [a -> b] -> [b]
mapX _ [] = []
mapX x (f:fs) = [f x] ++ (mapX x fs)

地图

map2 :: (a -> b -> c) -> [a] -> [b] -> [c]
map2 _ [] [] = []
map2 f (ax:axs) (bx:bxs) = [f ax bx] ++ map2 f axs bxs

这对我来说,是:all [] == 真实:

all  :: (a -> Bool) -> [a] -> Bool
all  _ [] = False
all  f l  = all f l

Does the ^ operator implement fast exponentiation?

fastPow :: Int -> Int -> Int
fastPow x 0 = 1
fastPow x a
    | even a     = exp2 * exp2
    | odd a      = exp2 * exp2 * x
    where
        exp2 = fastPow x (div a 2)

Answer 1

www.un.org/Depts/DGACM/index_spanish.htm 地图

map ($x) fs

$为功能应用程序操作者,(x)为将其论点应用于x<>。



Maps a binary function to two lists:

zipWith。 即便你没有通过在Hoogle上查询签字的类型,也能够发现这一点。

www.un.org/Depts/DGACM/index_spanish.htm ^运营商是否实施快速扩展?

Yes 。

友情链接