#>shapes_for_information
arrays
maps
trees
Software / Building Blocks
Shapes for Information
A data structure is a shape chosen for the questions you will ask. Arrays keep order and let you jump straight to a position; maps (dictionaries, hash tables) find a value by its key; trees keep things sorted or nested; graphs hold relationships; queues hold what is waiting its turn. Choosing well is most of the difference between a program that answers instantly and one that crawls.
Data Structures Essentials
Watch them move
VisuAlgo animates common structures and the operations on them.
visualgoA university course, free
MIT's introduction to algorithms, built around data structures.
mit ocw: 6.006The catalog
A long list of structures, each with its trade-offs.
wiki: data structures