代写数据结构中的目录树，实现目录结构的打印。
Requirement
In this part of the project, you will be implementing a basic directory-tree
structure that is derived from a base tree structure. Besides a vector of
children nodes, a directory-tree node contains a directory name along with
names of files in the directory. The directory-tree structure is a simple
familiar example of a tree, and you will need the completed base tree
structure for Part 4 in order to build an Abstract Syntax Tree using the
classes – Token class and classes derived from it – from Part 2.
If we have following structure of directories and files:
test_dir
│ mainFile.txt
│
├───Books
│ textfile.txt
│
├───Lectures
│ | bitmap.bmp
│ | spreadsheet.xlsx
│ ├───Course1
│ └───Course2
│
├───Music
│ songs.zip
│
├───Notes
│ | first.txt
│ └───one
│
└───Video
Then the generated tree for that will be here, where each directory is treated
as a node of the tree and the files of that directory can be stored in a
vector of strings in that node.
This code introduces the notion of function pointers. For example, member
function count_traverse in class TreeNode calls member function
traverse_children_post_order and passes in a pointer to itself
(count_traverse) and also a pointer to the count_action function. As shown in
function print_traverse in class Directory, with a bit of effort it is also
possible to pass to traverse_children_post_order pointers to member functions
from a derived class.
Using indirect recursion, member function print_traverse traverses the nodes
in the tree and, using member function print_action, prints out the
information about the directories. As distributed, print_traverse traverses
all nodes in post order fashion. Modify print_traverse so that it obeys the
following rules:
- If a given node has two children, then traverse the children using an in-order traversal (i.e. given node processed inbetween the children’s subtrees)
- If the node has more than two children, then traverse the children using a pre-order traversal (i.e. children processed after the given node)
- If the node has less than two children, then use post-order traversal at that point
You can search on the web for pre-order, in-order and post-order traversal.
One useful resource is https://en.wikipedia.org/wiki/Tree_traversal
For the tree shown above, the output of traversing the nodes all in post-order
fashion should look as follows:
Books | 0 -textfile.txt
Course1 | 0
Course2 | 0
Lectures | 2 -bitmap.bmp -spreadsheet.xlsx
Music | 0 -songs.zip
One | 0
Notes | 1 -first.txt
Video | 0
test_dir | 5 -mainFile.txt
Note: We are providing you the directory named “test_dir” in the template
project, which contains the directory structure explained above. You are free
to copy those directories and expand on them in order to do further testing
for yourself. Do keep a copy of “test_dir” as-is, however, as we may mark your
work using the provided “test-dir” and therefore you might want to check that
your code still works with that directory structure before you submit.
Instructions for submitting your code:
Do not modify the names of the .cpp and .hpp files given to you. For this part
of the project, you will be submitting the files Directory.hpp and
TreeNode.hpp. Also, do not modify the stream output to the stream given by
macro OUT, as we will likely be using that for marking.
