Frequently Asked Questions

Note: I am putting these here because students have asked them in the past, this is not a reflection of what will be on quizzes. 

Q: Does Big O refer only to data structures? 

A: No, Big O can be applied to all algorithms.

Q: If I create int x = 4, versus if I create int x = 2 + 2, would the latter take the computer twice as long to run since it has to solve an equation as well as assign x to 4?

A: Yes, the computer would have to compute the value of 2+2 and then assign x the value of 4 but the time complexity of both of those operations is constant O(1) and O(2) since you aren't getting any input in. We only worry about time complexity when we get input into the algorithm from a user or from reading in data. 

Q: What is the x value of the displayed graph?

A: The n, or number of inputs the algorithm has to process. 

Q: Why does the time that the algorithm run matter?

A: When you have a lot of data writing an algorithm that takes less time to run can mean the difference between getting the results in minutes or days or not in your life time.