Diagnostic
Covered it, or know it?
Forty questions across eight core areas. On each one, mark how sure you are alongside your answer — the gap between the two is what we actually measure.
Data Structures
Lookup in a hash table is O(1) on average. What is it in the worst case?
How sure are you of that answer?
Your answers stay in this browser. You can stop early; only what you answered is scored.