Pick the wrong structure and fast code turns slow.

What this data structures test covers, in short

Twenty multiple-choice questions at first-year undergraduate level, four on each of five topics: arrays and linked lists, stacks and queues, hash tables, trees, and graphs and heaps. They test what each structure is good at and how much its operations cost in Big O terms.

Costs are the usual average-case figures taught in introductory courses. Code snippets use Python-like pseudocode. The test is our own and not normed.