40 Algorithms Every Programmer Should Know

Selecting an algorithm

How do you know which one is a better solution? How do you know which algorithm runs faster? Time complexity and Big O notation (discussed later in this chapter) are really good tools for answering these types of questions.

To see where it can be useful, let's take a simple example where the objective is to sort a list of numbers. There are a couple of algorithms available that can do the job. The issue is how to choose the right one.

First, an observation that can be made is that if there are not too many numbers in the list, then it does not matter which algorithm do we choose to sort the list of numbers. So, if there are only 10 numbers in the list (n=10), then it does not matter which algorithm we choose as it would ...