AQA A-level Computer Science (7517)Specification point 4.4.4.3

AQA 7517 4.4.4.3: Order of complexity

The free BugBot lessons that teach this point, a robot to try it on, and the past-paper questions that test it.

What it covers

The last lesson counted operations as a function of n. Big O notation is the shorthand for that function's growth. It throws away the detail that stops mattering when n is large, and keeps the one thing that does: the shape of the curve.

  • Keep the dominant term, drop the constants
  • The orders you need
  • Deriving the complexity of code
  • Exponential growth in code
  • Best, average and worst case
  • Space complexity
Read the free lesson (25 min)

Or do it in the simulator, with tasks that mark themselves

Lessons that teach it

  1. A5.2 Big O notation Algorithms and complexity
    Dominant terms, the orders of complexity from O(1) to O(2^n), deriving complexity from code, best, average and worst case, and space…
  2. A5.9 Project: plan the route, then drive it Algorithms and complexity
    Choose and justify a route planner, build the mat's graph, find the shortest route with Dijkstra's algorithm and drive it.
  3. A15.7 Calculation and theory questions Exam preparation
    Number representation, floating point, Boolean logic, state machines and complexity answered quickly and checked.

Try it on a robot

The task from A5.2 Big O notation, running here. Change the program and press Run.

The specification is AQA's own document; this page says which of our lessons teach point 4.4.4.3 and is not endorsed by the board.