Python: Pushing all values onto a heap and then popping off the smallest values one at a time

Last update on April 23 2025 12:59:04 (UTC/GMT +8 hours)

3. Heapsort Implementation

Write a Python program to implement heapsort by pushing all values onto a heap and then popping off the smallest values one at a time.

Sample Solution:

Python Code:

import heapq as hq
def heapsort(iterable):
    h = []
    for value in iterable:
        hq.heappush(h, value)
    return [hq.heappop(h) for i in range(len(h))]
print(heapsort([1, 3, 5, 7, 9, 2, 4, 6, 8, 0]))

Sample Output:

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to implement heapsort by inserting all elements into a heap using heapq.heapify, then repeatedly calling heappop to produce a sorted list.
• Write a Python script to demonstrate heapsort on a large list of integers and compare its output with Python’s built-in sorted() function.
• Write a Python function that sorts a list using the heap queue algorithm and prints the intermediate heap states during sorting.
• Write a Python program to implement heapsort on a list of floating-point numbers and then validate that the final list is in ascending order.

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• Python Heap Queue Algorithm Exercises Home ↩
• Python Exercises Home ↩

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