using System;

using System.Collections.Generic;

​

#nullable enable

public class Program

{

    public static void Main()

    {

        var files = PopulateFiles();

        Console.WriteLine(PrintTree(files));

    }

    // PrintTree should output alphabetically folders and then their files/folders:

    // Root

    // |- Data (folder)

    // |--- CSV (folder)

    // |----- A.csv

    // |----- B.csv

    // |--- Images (folder)

    // |----- Cats.png

    // |----- MyFace.jpg

    // |- Logs (folder)

    // |--- log_2022-05-09.log

    // |--- log_2022-05-10.log

    private static string PrintTree(List<File> files) {

        // TODO: your code here.

        return "";

    }

    private static List<File> PopulateFiles() {

        var data = new Folder("Data");

        var csv = new Folder("CSV", data);

        var images = new Folder("Images", data);

        var logs = new Folder("Logs");

        var files = new List<File>();

        files.Add(new File("A.csv", csv));

        files.Add(new File("B.csv", csv));

        files.Add(new File("Cats.png", images));

        files.Add(new File("log_2022-05-09.log", logs));

        files.Add(new File("log_2022-05-10.log", logs));

        files.Add(new File("MyFace.jpg", images));

​

        return new List<File>();

    }

    private class Folder {

        public string Name { get; init; }

        public Folder? ParentFolder { get; init; }

        public Folder(string name, Folder? parent = null) {

            Name = name;

            ParentFolder = parent;

        }

    }

    private class File {

        public string Name { get; init; }

        public Folder Folder { get; init; }

        public File(string name, Folder folder) {

            Name = name;

            Folder = folder;

        }

    }

}