URL

https://leetcode.com/problems/n-ary-tree-postorder-traversal/description/?envType=daily-question&envId=2024-08-26

Code

https://github.com/syohex/dotnet-study/blob/master/fsharp/leetcode/challenge/202408/n-ary-tree-post-order-traversal/main.fsx

type Node =
    | Leaf
    | Node of int * Node list

let postorder (root: Node) : int list =
    let rec postorder' node acc =
        match node with
        | Leaf -> acc
        | Node(v, children) ->
            let acc = children |> List.fold (fun acc child -> postorder' child acc) acc
            v :: acc

    postorder' root [] |> List.rev