A recusive approach is used for this problem. There is a for loop to print all the files in the current path. And, for all subdirectories, a recusive call is made.
The total time complexity is quadratice because O(n), where n is number of files, for the first foor loop, and we are doing recursive call for all subdirectories, which will be O(m-1), where m is number of subdirectories. The total complexity comes to O(n)*O(m-1), which is quadratic.
The space complexit of the algorithm is linear because there is a list called paths_list, which grows along with the input (number of paths) size.