FAQ: Merge Sort: Conceptual - Merge Sort Performance

Community%20FAQs%20on%20Codecademy%20Exercises

This community-built FAQ covers the “Merge Sort Performance” exercise from the lesson “Merge Sort: Conceptual”.

Paths and Courses
This exercise can be found in the following Codecademy content:

Sorting Algorithms

FAQs on the exercise Merge Sort Performance

There are currently no frequently asked questions associated with this exercise – that’s where you come in! You can contribute to this section by offering your own questions, answers, or clarifications on this exercise. Ask or answer a question by clicking reply (reply) below.

If you’ve had an “aha” moment about the concepts, formatting, syntax, or anything else with this exercise, consider sharing those insights! Teaching others and answering their questions is one of the best ways to learn and stay sharp.

Join the Discussion. Help a fellow learner on their journey.

Ask or answer a question about this exercise by clicking reply (reply) below!

Agree with a comment or answer? Like (like) to up-vote the contribution!

Need broader help or resources? Head here.

Looking for motivation to keep learning? Join our wider discussions.

Learn more about how to use this guide.

Found a bug? Report it!

Have a question about your account or billing? Reach out to our customer support team!

None of the above? Find out where to ask other questions here!

Why is merge sort O(N * LOG N) and not instead O(N + LOG N). I ask because splitting the original list into singleton will take O(LOG N) steps, after which we’ll merge those O(N) singletons. Isn’t that O(N + LOG N)?

1 Like

Yes, the divide and conquer is O(log(n)), and merge is O(n), but there is not just one merge, there is one for every divide step.

Good analysis here.

1 Like

If you think of it like a geometric shape where the area is the amount of work required…

The first row is the single array
then two halves
four fourths
eight eights
… N ones

Each row is still N elements
Each row involves N work
How many rows are needed to split the array down into 1-size arrays?
You’ve now got a height and a width of the work that you can multiply for the total size.

1 Like