I knew the stack approach pretty quickly, split on slashes, skip empty strings and dots, pop on double-dots, done.
Use a stack to process the path components: split the path by '/', then iterate through each component. For each component, if it's '.' or empty, skip it; if it's '..', pop from the stack if not empty; otherwise, push the component. Finally, join the stack with '/' and prepend a '/' to form the canonical path.
Pro tip: Clarify edge cases upfront, such as multiple consecutive slashes, trailing slashes, and paths that reduce to root. Also, mention that you're handling the problem in O(n) time and O(n) space, which is optimal.
Restate the problem to ensure clarity. Identify edge cases like '/', '/../', '/home//foo/', and '/a/./b/../../c/'.
Select a stack (or list) to keep track of valid directory names as you process the path components.
Split the path by '/' and iterate. Skip empty strings and '.', pop for '..' if stack is not empty, otherwise push the directory name.
Join the stack elements with '/' and ensure the result starts with a single '/'. If the stack is empty, return '/'.
Walk through provided examples and edge cases to verify correctness and discuss time/space complexity.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.