Algorithms need somewhere to live. The data structures you choose to work with determine not just how your program is organised, but how fast it runs — sometimes by orders of magnitude.
This unit covers the fundamental abstract data types: containers, dictionaries, and priority queues. For each one, we look at how different underlying structures (arrays, linked lists, trees, hash tables) implement the same operations with very different performance trade-offs.
By the end of this unit you should be comfortable choosing the right data structure for a given problem, and understanding why that choice matters.