DSA · Theory

Difference between merge sort and quick sort

Theory

446/810

Difference between merge sort and quick sort

Difference between merge sort and quick sort is a DSA topic. In plain words you use it for names A→Z in the roll list. Don’t start with a slogan — start with that picture.

Smallest example: n log n vs n². Type it, run it, and say what you see. If you can do that from memory, you know Difference between merge sort and quick sort.

From the example next to this theory: Difference between merge sort and quick sort — quick sort partitions around a pivot, then sorts both sides.

Trap — unstable sort when equal keys matter. Fix that before you talk about advanced DSA.

Viva — what is Difference between merge sort and quick sort? Then show n log n vs n². Then name the trap.

Exam tip

What is Difference between merge sort and quick sort? Show this: n log n vs n². Trap: unstable sort when equal keys matter.

Example

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

print(quick_sort([5, 1, 4, 2, 3]))

Difference between merge sort and quick sort — quick sort partitions around a pivot, then sorts both sides.

Short notes

DefDifference between merge sort and quick sort — names A→Z in the roll list.
Rulen log n vs n²
Trapunstable sort when equal keys matter
Usethe roll list

def quick_sort(arr): if len(arr) <= 1: return arr pivot = arr[len(arr) // 2] left = [x for x in arr if x < pivot] mid = [x for x in arr if x == pivot] right = [x for x in arr if x > pivot] return quick_sort(left) + mid + quick_sort(right) print(quick_sort([5, 1, 4, 2, 3]))

Difference between merge sort and quick sort

Example

Short notes

Questions

Difference between merge sort and quick sort

Example

Short notes

Questions