我是一名有用的助手,可以为您进行文本翻译。以下是需要翻译的内容:
输出将是:
但我似乎无法弄清楚它。
我所能做的最好的就是
我正在尝试将一个列表分成两个部分,以便在输入为
[1,2,3,5,6]
输出将是:
[1,2,3][5,6]
但我似乎无法弄清楚它。
我所能做的最好的就是
[1,3,6][2,5]
。我正在尝试将一个列表分成两个部分,以便在输入为
[1,2,3,5,6]
[1,2,3][5,6]
[1,3,6][2,5]
。我是一个初学者。所以,如果有错误或不够优化的地方,请纠正我。
internalSplit :: [a] -> Int -> [a] -> [[a]]
split :: [a] -> [[a]]
internalSplit (first:rest) count firstPart
| count == 0 = [firstPart, (first:rest)]
| otherwise = internalSplit rest (count - 1) (firstPart ++ [first])
split myList =
let listLength = length myList
in
if listLength `mod` 2 == 0 then
internalSplit myList (listLength `div` 2) []
else
internalSplit myList ((listLength `div` 2) + 1) []
main = do
print $ split [1, 2, 3, 5, 6]
print $ split [1, 2, 3, 4, 5, 6]
输出
[[1,2,3],[5,6]]
[[1,2,3],[4,5,6]]
编辑:
成功使用内置函数并得出以下结果:
internalSplit :: [a] -> Int -> [[a]]
split :: [a] -> [[a]]
internalSplit myList splitLength = [(take splitLength myList), (drop splitLength myList)]
split myList =
let listLength = length myList
in
if listLength `mod` 2 == 0 then
internalSplit myList (listLength `div` 2)
else
internalSplit myList ((listLength `div` 2) + 1)
main = do
print $ split [1, 2, 3, 5, 6]
print $ split [1, 2, 3, 4, 5, 6]
输出
[[1,2,3],[5,6]]
[[1,2,3],[4,5,6]]
编辑1:
internalSplit :: [a] -> Int -> ([a], [a])
split :: [a] -> ([a], [a])
internalSplit myList splitLength = splitAt splitLength myList
split myList =
let listLength = length myList
in
if listLength `mod` 2 == 0 then
internalSplit myList (listLength `div` 2)
else
internalSplit myList ((listLength `div` 2) + 1)
main = do
print $ split [1, 2, 3, 5, 6]
print $ split [1, 2, 3, 4, 5, 6]
输出
([1,2,3],[5,6])
([1,2,3],[4,5,6])
编辑2
正如Bogdon在评论部分所建议的那样,这可以大大简化为如下内容。
split :: [a] -> ([a], [a])
split myList = splitAt (((length myList) + 1) `div` 2) myList
main = do
print $ split [1, 2, 3, 5, 6]
print $ split [1, 2, 3, 4, 5, 6]
输出
([1,2,3],[5,6])
([1,2,3],[4,5,6])
splitAt
呢?splitHalf l = splitAt ((length l + 1) `div` 2) l
。 提示:splitAt 函数可以将列表分成两部分,第一个参数指定切割点的位置。 - fjarri