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Data Structures

Arrays, lists, trees, hash tables and their trade-offs.

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This course has 3 lessons. Start with the first one and use the next / previous links at the bottom of each lesson — the sidebar keeps the whole course in order.

Lessons

  1. Arrays, linked lists, stacks and queuesContiguous memory versus pointers, why pop from the front is the classic performance mistake, and how to pick a container.
  2. Hash tablesHow hashing turns a key into a slot, what collisions and load factor do to performance, and what makes a key usable.
  3. Trees and choosing a structureBinary search trees, why balance decides everything, heaps for priority, and a decision table for real code.

More in Computer Science Fundamentals

Algorithms Computer Networks Operating Systems Character Encodings Hashing & Checksums Data Formats Dates & Time Regular Expressions

Last refreshed 2026-09-17.