Learn and practice
Reference
Operation costs and implementation assumptions to use when comparing interview solutions. Keep the reference beside your practice exercises.
Reference
Data structure time complexity reference
Compare arrays, hash maps, linked lists, stacks, queues, trees, and heaps with worst-case, expected, and amortized costs explained.
ReferencePython collections for interviews: dict, Counter, deque, and heapq
Choose Python collections by operation, write counts and adjacency lists, and test queue, heap, missing-key, and copying behavior.