I started by splitting both paths on '/' and finding the common prefix, which is the right instinct.
Split both paths into components, find the longest common prefix, then construct the relative path by going up (..) for each remaining component in the source and down into the remaining components of the target. Handle edge cases like identical paths, root directory, and trailing slashes. Explain the algorithm clearly and discuss time/space complexity.
Pro tip: Mention that this is essentially a string manipulation problem but requires careful handling of path semantics (e.g., absolute paths always start with '/', and '..' from root stays at root). Also, consider if the target is a subdirectory of the source, the relative path is just the remaining components without any '..'.
Confirm that both paths are absolute and may contain trailing slashes. Normalize by removing trailing slashes (except for root) and splitting into components.
Iterate through both component lists simultaneously to find the longest prefix of directories they share. This represents the common ancestor directory.
For each remaining component in the source path after the common prefix, add '..'. Then append the remaining components of the target path. Join with '/'.
If the paths are identical, return '.' or an empty string (depending on convention). If the target is the root, the relative path is just the necessary '..'s. If the source is the root, the relative path is the target path without leading slash.
State that time complexity is O(n) where n is the total number of components, and space is O(n) for storing components. Walk through a few examples to verify correctness.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.