What is Heap Sort and how is it implemented?
A sorting algorithm question focusing on the heap data structure and its application.
Why Interviewers Ask This
Heap Sort demonstrates understanding of tree structures and in-place sorting algorithms with guaranteed O(n log n) complexity.
How to Answer This Question
Explain building a max-heap, swapping the root with the last element, reducing heap size, and heapifying. Mention its space efficiency compared to Merge Sort.
Key Points to Cover
- Max-heap construction
- Root swap and reduction
- Heapify operation
- Space efficiency
Sample Answer
Heap Sort works by first building a max-heap from the input data. The largest element is at the root. We swap it with the last element, reduce the heap size by one, and heapify the root to restore the max-heap property.…
Common Mistakes to Avoid
- Confusing min-heap and max-heap
- Incorrect heapify logic
- Overlooking in-place nature
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