Looked simple and I kind of rushed into coding without thinking through the edge cases first.
Start by clarifying the requirements and edge cases, then choose a data structure that balances efficiency for the given operations. For a line-based editor, a dynamic array (like a list) is often sufficient, but consider a balanced tree or skip list if frequent insertions at arbitrary positions are expected. Walk through the algorithm, analyze time and space complexity, and discuss trade-offs.
Pro tip: Mention that you would use a data structure that supports O(log n) insertions and deletions, such as a balanced binary search tree or a skip list, if the document is large and operations are frequent. This shows you think beyond the naive solution and consider scalability.
Ask about the expected size of the document, frequency of operations, and whether deletions are always of the entire document or can be partial. Confirm the input format and output expectations.
Evaluate options: dynamic array (O(n) insert/delete), linked list (O(n) for index access but O(1) insert/delete if position known), balanced BST or skip list (O(log n) for both). Select based on trade-offs.
Iterate through events. For insert, insert the line at the given index. For delete, clear the document. Handle edge cases like invalid indices or empty document.
Compute time and space complexity for the chosen approach. Discuss potential optimizations, such as using a rope or gap buffer for text editors, and when they might be beneficial.
Walk through a few test cases, including edge cases (insert at beginning, end, middle; delete when empty; multiple deletes). Ensure the solution handles all scenarios correctly.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.