Question

我是F＃的新手，并试图弄清楚一些基本知识，但我慢慢地磕磕绊绊。在下面的代码中，我试图生成一个随机整数列表，然后对其进行排序。

let randomNumberList count =
    let r = System.Random()
    List.init count (fun _ -> r.Next(100))

let rec selectionSort l = function
    | [] -> []
    | l -> let min = List.min l in
           let rest = List.filter (fun i -> i <> min) l in
           let sortedList = selectionSort rest in
           min :: sortedList
sortedList = selectionSort l

let unsortedList = randomNumberList 10
printfn "%A" unsortedList
printfn "%A" sortedList

所以有两件事......一件是我得到的错误：

stdin(515,19): error FS0001: This expression was expected to have type
    'a list    
but here has type
    'a list -> 'a list

另一个是随机数列表。它有效，但我希望生成的数字小于100，而不是我现在得到的大量值。

感谢您的耐心和帮助！

Answer 1

正如评论中所述，l中不需要let rec selectionSort。固定代码：

let randomNumberList count =
    let r = System.Random()
    List.init count (fun _ -> r.Next(100))

let rec selectionSort = function
    | [] -> []
    | l -> let min = List.min l in
           let rest = List.filter (fun i -> i <> min) l in
           let sortedList = selectionSort rest in
           min :: sortedList

let unsortedList = randomNumberList 10
let sortedList = selectionSort unsortedList
printfn "%A" unsortedList
printfn "%A" sortedList
System.Console.ReadLine() |> ignore

说明：

let vname = function
   | ... -> ...
   | ... -> ...

是

的缩写形式

let vname arg = match arg with
   | ... -> ...
   | ... -> ...

F＃选择排序随机整数列表

1 个答案: