小编Cam*_*Bak的帖子

我创建了一个函数m，这样

m "abc" "def" == "bcd" 

我想创建另一个函数，用于在给定输入时m生成输出["bcd","efg","hia"]["abc","def","ghi"]

的定义m是

m :: [a] -> [a] -> [a]
m str1 str2 = (drop 1 str1) ++ (take 1 str2)

import Data.List (sort,nub,(\\),transpose,genericLength)
import Data.String (lines,unlines)


type Row a    = [a]
type Matrix a = [Row a]
type Digit    = Char

digits :: [Digit]
digits = ['1'..'9']

blank :: Digit -> Bool
blank d = d == ' '

-- 1.
group :: [a] -> [[a]]
group = groupBy 3

groupBy :: Int -> [a] -> [[a]]
groupBy _ [] = [] 
groupBy n xs = let (ys, zs) = splitAt n xs
               in  ys : groupBy n zs

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