树的打印Q43

前置

本题需要你已经有一个树的基本结构，

你可以导入 Q42 的代码，完成这道题

要求

从以下三种格式之一 挑一个 打印出来

样式1

Menu
+   File
|   +   New Window
|   +   New File
|   +   Open Recent
|   |   +   201709
|   |   +   201711
|   +   Save
|   +   Save As
|       +   PDF
|       +   Image
+   Edit
|   +   Add Node
|   +   Delete Node
+   View
    +   View Symbol
    +   View Class
    +   Panels
        +   Color
        +   Picture

样式2

Menu {
    File {
        New Window
        New File
        Open Recent {
            201709
            201711
        }
        Save
        Save As {
            PDF
            Image
        }
    }
    Edit {
        Add Node
        Delete Node
    }
}

样式3

Menu
1 File
1.1 New Window
1.2 New File
1.3 Open Recent
1.3.1 201709
1.3.2 201711
1.4 Save
1.5 Save As
1.5.1 PDF
1.5.2 Image
2 Edit
2.1 Add Node
2.2 Delete Node
3 View
3.1 View Symbol
3.2 View Class
3.3 Panels
3.3.1 Color
3.3.2 Picture