A Common-Sense Guide to Data Structures and Algorithms

Practical Examples

Here’s some typical Python code that prints out all the items from a list:

things = ['apples', 'baboons', 'cribs', 'dulcimers']

for thing in things:
    print "Here's a thing: %s" % thing

How would we describe the efficiency of this algorithm in Big O Notation?

The first thing to realize is that this is an example of an algorithm. While it may not be fancy, any code that does anything at all is technically an algorithm—it’s a particular process for solving a problem. In this case, the problem is that we want to print out all the items from a list. The algorithm we use to solve this problem is a for loop containing a print statement.

To break this down, we need to analyze how many steps this algorithm takes. ...