Algorithms Analysis Practice Test 2025 - Free Algorithms Practice Questions and Study Guide

Merge Sort performs better than QuickSort in scenarios where the data is nearly sorted or when stability is a requirement.

When data is nearly sorted, Merge Sort's performance can be more consistent because it divides the data into smaller chunks and merges them back together, effectively minimizing the number of comparisons needed. This can lead to better performance in cases where the input data is close to being sorted, as Merge Sort has a guaranteed time complexity of O(n log n) regardless of the initial order of elements. This predictability contrasts with QuickSort, which may degrade to O(n^2) in the worst-case scenarios (e.g., when the pivot selection is poor).

Furthermore, Merge Sort is a stable sorting algorithm, meaning it maintains the relative order of records with equal keys. This stability is often required in applications where the order of similar elements is significant. For example, if sorting a list of names by last names while keeping the original order of first names, Merge Sort would be preferable because it ensures that the initial order of equal elements is preserved.

In contrast, QuickSort may not guarantee stability, making it less suitable for scenarios where the order of equivalent elements is important. Additionally, Merge Sort has a consistent performance advantage over QuickSort when the data is