Resumable Iterator for List and File

Problem: Design a Resumable Iterator Design and implement a resumable iterator. In addition to normal iteration, it must be able to save its current state and later resume from that state. The interview usually expects you to: Design detailed test cases first; Then implement the iterator; Cover state saving, state restoration, and boundary cases. Part 1: List Iterator Implement ListResumableIterator for a list of strings. It should support: has_next() -> bool: returns whether there is another element; next() -> str: returns the next element, or raises StopIteration if exhausted; get_state() -> dict: returns a serializable state; set_state(state: dict) -> None: restores the iterator to a previous state. Assumptions: The list does not change between saving and restoring state; The state should contain only the minimum information required to resume. Part 2: File Iterator Follow-up Extend the design to a file iterator FileLineResumableIterator. The file iterator iterates line by line and supports the same operations: has_next() -> bool next() -> str get_state() -> dict set_state(state: dict) -> None Assumptions: The file content does not change between saving and restoring state; Each call to next() returns one line without the trailing newline character; After restoring, the iterator should continue from the exact saved position. Constraints List length: 0 <= n <= 10^5; String length: 0 <= len(s) <= 10^3; File size: up to 10^8 bytes; Number of operations: up to 10^5. Example Test Scenarios Example 1: Save and restore a list iterator items = ["a", "b", "c"] next() -> "a" save state next() -> "b" restore state next() -> "b" next() -> "c" has_next() -> false Example 2: Empty list items = [] has_next() -> false next() -> StopIteration Example 3: Save and restore a file iterator File content: line1 line2 line3 Operations: next() -> "line1" save state next() -> "line2" restore state next() -> "line2" next() -> "line3" has_next() -> false Example Input LIST 3 a b c 8 HAS NEXT SAVE s1 NEXT LOAD s1 NEXT NEXT HAS Output true a saved:s1 b loaded:s1 b c false