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Quick Sort vs Merge Sort

Theory

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Quick Sort vs Merge Sort

Quick Sort vs Merge 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 Quick Sort vs Merge Sort.

From the example next to this theory: Quick Sort vs Merge 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 Quick Sort vs Merge Sort? Then show n log n vs n². Then name the trap.

Exam tip

What is Quick Sort vs Merge 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]))

Quick Sort vs Merge Sort — quick sort partitions around a pivot, then sorts both sides.

Short notes

DefQuick Sort vs Merge 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]))

Quick Sort vs Merge Sort

Example

Short notes

Questions

Quick Sort vs Merge Sort

Example

Short notes

Questions