Start by clarifying the problem: define the input (root node of a directory tree) and output (indented string representation). Then, implement a recursive DFS that traverses each directory, printing its name with appropriate indentation before recursing into its children. Finally, discuss edge cases and potential optimizations.
Pro tip: Mention that you would use a depth parameter to control indentation and that you'd handle both files and directories uniformly, but only recurse into directories. Also, note that you'd avoid using string concatenation in a loop for performance, opting for a list of strings or a StringBuilder.
Confirm the input format (e.g., a Node class with name, isDirectory, and children) and output format (e.g., string with indentation). Ask about sorting order, handling of hidden files, and whether to include the root.
Outline a recursive function that takes a node and depth. Print the node's name with indentation based on depth, then if it's a directory, iterate over its children and recursively call the function with depth+1.
Write clean code, using a helper function for indentation (e.g., repeating ' ' or '|-- '). Ensure base case: if node is null, return. Use a list to collect lines for efficiency.
Walk through a simple tree, then test edge cases: empty directory, single file, deep nesting, and large tree. Discuss time and space complexity: O(n) time, O(h) space for recursion stack.
Mention iterative DFS with a stack if recursion depth is a concern, or BFS if level-order is needed. Also, discuss handling symbolic links or permission errors.
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