Algorithms which are O(n), O(n log n), quadratic order, etc.

This video covers what you need to know for Decision Maths AS about “order” and “efficiency” of algorithms.

The terminology is a bit odd – the usual thing is to describe O(n), O(n2), O(n log n) as the time-complexity of an algorithm and sometimes as its “efficiency”. Run-time usually means time, in actual seconds or whatever, on a particular computer in a particular implementation. But this video will do.