My first instinct was to reach for a linked list and I think that was the right call, but I fumbled explaining why.
Start by clarifying the requirements and constraints, then propose a data structure (e.g., two stacks or a doubly linked list) and explain how it supports back, forward, and new page visits. Walk through the operations with examples, analyze time/space complexity, and discuss trade-offs and potential optimizations.
Pro tip: Mention that the forward stack is cleared when visiting a new page, and discuss how to handle edge cases like no back/forward history. Also, consider scalability for large histories and potential memory optimizations.
Ask questions to understand expected behavior: maximum history size, whether to store full URLs or just identifiers, and if persistence across sessions is needed.
Propose using two stacks (back and forward) or a doubly linked list with a pointer. Explain why it fits the operations.
Detail how back, forward, and visit(newPage) work with the chosen structure, including edge cases (e.g., empty stacks).
State time and space complexity for each operation (typically O(1) time, O(n) space) and discuss trade-offs between structures.
Mention potential improvements like limiting history size, using a circular buffer, or persisting history to disk.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.