Intermediate Topic 18 of 51 Algorithms
Heap Sort
Sorting by repeatedly extracting the maximum from a heap.
How it works
Build a max-heap, then repeatedly swap the root with the last element and sift down. It is O(n log n) in all cases, in place, but not stable.
Where it is used
Guaranteed worst-case performance with O(1) extra memory.
Common pitfall
Poor cache behavior makes it slower than quicksort in practice.
Where it fits in the course
Heap Sort is topic 18 of 51 in Algorithms, rated Intermediate. It follows Sliding Window. The next topic is Shell Sort.
Practice and explore
- Open the interactive lesson, with a mini quiz.
- Take the Algorithms quiz.
- Explore the Sorting Algorithms visualizer: Bubble, selection, insertion, merge and quick sort animated.
How to study this topic
- Read the explanation above and restate the definition in your own words.
- Open the interactive lesson and answer its mini quiz.
- Read the common pitfall, then write a short example that avoids it.
- Check your understanding in the Algorithms quiz, and revisit the topic if you miss a question.
Frequently asked questions
What is Heap Sort?
Sorting by repeatedly extracting the maximum from a heap. It belongs to Algorithms and is an intermediate-level topic.
Where do people use Heap Sort?
Guaranteed worst-case performance with O(1) extra memory.
What is the most common mistake with Heap Sort?
Poor cache behavior makes it slower than quicksort in practice.
What should I learn before this topic?
Start with Sliding Window, the topic just before it in Algorithms.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Algorithms quiz. You can also explore Sorting Algorithms in the Visual Lab.
Is Heap Sort hard to learn?
It is an Intermediate topic. Be comfortable with the Beginner topics in this area first, then read the common pitfall carefully, since it is where most mistakes happen.
How long does it take to learn Heap Sort?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to Heap Sort?
Sliding Window, Shell Sort, Two Pointers are closely connected. The full list is in the related topics section of this page.
What should I study after Heap Sort?
Continue with Shell Sort, the next topic in Algorithms.
Related topics
- Sliding Window (Algorithms)
- Shell Sort (Algorithms)
- Two Pointers (Algorithms)
- Bucket Sort (Algorithms)
- Stack vs Heap (Languages & Compilers)
- Binary Heap Operations (Data Structures)