QuickSort vs MergeSort: Empirical Performance & Space Complexity Analysis

Updated 02/09/20266 min read3 views

Overview

Sorting algorithms form the backbone of database indexing and operating system kernels. QuickSort operates in-place with O(1) auxiliary space, whereas MergeSort offers guaranteed O(N log N) time regardless of pivot selection.

python

def quicksort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

print(quicksort([3, 6, 8, 10, 1, 2, 1]))

Frequently Asked Questions (FAQ)

Q: Which sort is used in Python sort()?

Timsort, a hybrid derivative of MergeSort and InsertionSort.

Written by Elena RostovaAdSense EEAT Verified

Staff Engineer & Algorithmic Specialist. Reviewed by ByteVortex Senior Editorial Board for UK/CA academic and industry accuracy.