How to Do a Quicksort in Python (Simple)

How to Do a Quicksort in Python (Simple)

Greetings, in this Pythin tutorial we shall be looking at how to do a quick sort in Python.

QuickSort is a divide-and-conquer sorting algorithm. It works by selecting a 'pivot' element from the array and partitioning the other elements into two sub-arrays, according to whether they are less than or greater than the pivot. The sub-arrays are then sorted recursively. This process continues until the base case is reached, where a sub-array has only one or zero elements. Once all the sub-arrays are sorted, they are combined to produce a single, sorted array.

Step-by-Step Example: Consider the array: [9, 7, 5, 11, 12, 2, 14, 3, 10, 6]

1. Choose a pivot: Let's select 11 as the pivot (though there are many strategies for pivot selection; for simplicity, we're picking a middle element).
2. Partitioning: Rearrange elements based on the pivot.
   • Elements less than 11: [9, 7, 5, 2, 3, 6]
   • Pivot: 11
   • Elements greater than 11: [12, 14, 10]
3. Recursively apply QuickSort:
   • For [9, 7, 5, 2, 3, 6]: Let's choose 5 as the pivot.
     • Elements less than 5: [2, 3]
     • Pivot: 5
     • Elements greater than 5: [9, 7, 6]
   • For [12, 14, 10]: Let's choose 12 as the pivot.
     • Element less than 12: [10]
     • Pivot: 12
     • Element greater than 12: [14]
4. Continue recursion: This process continues recursively until each sub-array is of size 1 or 0.
5. Combine: As recursion unwinds, the arrays are combined together, resulting in the sorted array: [2, 3, 5, 6, 7, 9, 10, 11, 12, 14]

Note: The efficiency of QuickSort heavily relies on the pivot choice. In the worst case, it has a time complexity of O(n^2), but with good pivot choices and on average cases, it can achieve O(n log n).

Thanks for watching this tutorial on how to do a quick sort using Python.

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How to Do a Quicksort in Python (Simple) How to Do a Quicksort using Python ... https://www.youtube.com/watch?v=qJgcvK9n2Vw