What is Heapify? Explain the process.

Difficulty: 5/10

heap construction, in‑place heapify, time complexity

Heapify

Heapify is the process of restoring the heap-order property. For a node, we compare it with its children, select the appropriate child according to min-heap or max-heap ordering, swap when necessary, and continue downward. Bottom-up heap construction applies this process from the last non-leaf node toward the root and builds a heap in O(n) time.

javascript

1
Sift-down heapify for one node is O(log n).
2
Bottom-up construction of a heap is O(n).
3
Heapify does not mean sorting the array.
4
After heapify, the heap-order property is restored.

Scenario Questions

0-2 years experience

2-5 years experience

Follow-up Questions