A Common-Sense Guide to Data Structures and Algorithms

Chapter 4Speeding Up Your Code with Big O

Big O Notation is a great tool for comparing competing algorithms, as it gives an objective way to measure them. We’ve already been able to use it to quantify the difference between binary search vs. linear search, as binary search is O(log N)—a much faster algorithm than linear search, which is O(N).

However, there may not always be two clear alternatives when writing everyday code. Like most programmers, you probably use whatever approach pops into your head first. With Big O, you have the opportunity to compare your algorithm to general algorithms out there in the world, and you can say to yourself, “Is this a fast or slow algorithm as far as algorithms generally go?”

If you find that Big O labels ...