Here are five Big O run times that you’ll encounter a lot, sorted from fastest to slowest: O(log n), also known as log time. Example: Binary search. O(n), also known as linear time. Example: Simple search. O(n * log n). Example: A fast sorting algorithm, like quicksort (coming up in chapter 4). O(n2). Example: A slow sorting algorithm, like selection sort (coming up in chapter 2). O(n!). Example: A really slow algorithm, like the traveling salesperson (coming up next!).
