Programming :: Detecting Newly Created Folders / Files On Local File System?

Using C++, I want to process sub-folders on my home folder sequentially each with a special naming format and containing some binary files in it:

Code:
1/
2/
3/
4/
5/
6/
...

Give above folders, I will process files in 1/ at first, 2/ at second, 3/ at third, and so on.

For some n/ folder, if I realize that n/ actually does not exist in local file system, I do not want to wait for it. Hence I will keep processing (n+1)/ folder, and so on.

However, when processing some (n+m)/ folder, previously not processed n/ folder may have been created on local file system. In this case, I do not want to miss processing it, but somehow detect its creation and process it. After processing n/ folder, I want to continue from (n+m+1)/.