I store [data] and do
[operations] often. Compare
three data structures with the
cost of each operation, pick
one, and say what that choice
costs me elsewhere.

Pick the Right Data Structure

The trade-off named, not just the recommendation.

Prompt

I need to store [describe the data] and do [describe the operations] frequently. Compare three data structures for this, with the cost of each operation, and say which one you'd choose and what it costs me elsewhere.