Sounds basic until you're actually on the call trying to give a structured answer in under five minutes.
Start by defining both data structures and contrasting their memory layout and performance characteristics. Then discuss trade-offs in terms of access, insertion, deletion, and memory overhead, and conclude with practical scenarios for choosing one over the other.
Pro tip: Mention that modern hardware and language implementations (e.g., ArrayList in Java, vector in C++) often make arrays the default choice due to cache locality, and that linked lists are rarely optimal unless you need constant-time insertions/deletions at known positions or are implementing other structures like stacks/queues.
Briefly explain that an array is a contiguous block of memory with fixed size (or dynamic resizing), while a linked list is a collection of nodes where each node points to the next (and possibly previous).
Highlight that arrays allow O(1) random access via indexing, while linked lists require O(n) traversal. Also note that arrays have better cache locality, whereas linked lists have extra memory overhead for pointers.
Explain that arrays have O(n) insertion/deletion due to shifting elements, while linked lists can do O(1) insertion/deletion if the position is known (e.g., at head or with a reference to the node).
Mention that dynamic arrays (like ArrayList) amortize resizing costs but may waste memory, while linked lists grow incrementally but incur pointer overhead and potential fragmentation.
Summarize when to pick each: arrays for frequent random access, cache efficiency, and known size; linked lists for frequent insertions/deletions at arbitrary positions, unknown size, or when implementing other structures like stacks/queues.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.