Clarify the rules for path resolution (absolute vs relative, ., .., redundant slashes) and edge cases. Then propose a stack-based algorithm that processes path segments, handling .. by popping from the stack when possible. Finally, discuss complexity and potential trade-offs.
Pro tip: Mention that you would use a stack (or deque) to efficiently handle .. and that you must consider edge cases like root directory and paths that go above root. Also, note that the solution should be O(n) time and O(n) space.
Ask about handling of . and .., redundant slashes, and whether the path can go above root. Confirm that the output should be a canonical absolute path.
Use a stack to store path components. Split the path by '/', iterate over segments, and for each segment: if it's '..', pop from stack if not empty; if it's '.' or empty, skip; otherwise push.
If the target path starts with '/', start with an empty stack (absolute). Otherwise, initialize the stack with the components of the current working directory.
Join the stack elements with '/' and prepend '/' to form the absolute path. Handle the case of empty stack (root) by returning '/'.
State that time complexity is O(n) where n is the length of the path, and space is O(n) for the stack. Walk through examples to verify correctness.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
This is where things got interesting in a bad way.
Clarify the symlink resolution semantics (e.g., whether to resolve all symlinks or only those in intermediate components) and then describe a step-by-step algorithm that resolves each path component, detects cycles using a visited set, and handles multi-hop chains by iterating until a non-symlink is found. Emphasize edge cases like symlinks pointing to absolute paths, relative paths, and the root directory.
Pro tip: Mention that you would limit the number of symlink resolutions to prevent infinite loops (e.g., a max depth of 40 like Linux) and discuss the trade-off between eager vs lazy resolution for performance.
Ask whether the symlink map is static or dynamic, whether symlinks can point to absolute or relative paths, and whether the goal is to resolve the entire path or just intermediate components.
Process the path component by component, maintaining a current directory. For each component, check if it's a symlink; if so, replace it with its target and restart resolution from the target's base.
Use a visited set to detect cycles and a counter to limit the number of symlink resolutions (e.g., max 40). If a cycle or limit is exceeded, return an error.
Consider symlinks pointing to absolute paths, relative paths, the root directory, and symlinks in the final component. Also handle non-existent paths and permission errors.
Discuss time complexity (O(n * m) where n is path length and m is max symlink depth) and space complexity (O(m) for the visited set). Mention caching resolved paths for performance.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.