Choose the right data structure

What this quiz helps you practice

Choosing a data structure is often about trade-offs: speed vs memory, simplicity vs flexibility, and average-case vs worst-case performance. This quiz trains you to recognize patterns in problem statements and map them to the structure that fits.

Each question is multiple-choice with 4 options and no timer, so you can think through constraints like lookup frequency, insertion patterns, ordering needs, and concurrency concerns.

Difficulty and question settings

Difficulty is mixed on purpose: you’ll see quick wins (e.g., “need LIFO”) alongside nuanced cases (e.g., “need fast membership checks plus ordering”). You can also choose your preferred question count and difficulty before starting, making it easy to do a short warm-up or a full deep practice session.

Common pitfalls to avoid

Many wrong answers come from over-focusing on one operation (like fast search) while ignoring others (like frequent inserts, deletions, or range queries). Another common trap is picking a structure you know well instead of the one that matches the constraints.

• Confusing arrays vs linked lists when insert/delete patterns dominate
• Using a stack/queue when you actually need random access or priority ordering
• Reaching for a hash map without considering ordering or range queries
• Missing when a heap is better than sorting repeatedly
• Treating trees and graphs as interchangeable when relationships differ

Tips to get more out of every attempt

After each question, ask yourself which operations must be fast and which can be slower, then validate your choice against edge cases. If you miss a question, rewrite the scenario in terms of operations (search, insert, delete, min/max, traversal) and try again with a different difficulty setting.