In this tutorial, we will discuss a Python program for a quick sort algorithm to sort an array of numbers in ascending order.

Before going to the program first, let us understand what is Quick Sort.

Quick Sort:

• Quick sort is an efficient, divide-and-conquer sorting algorithm that selects a “pivot” element and partitions the array into two sub-arrays based on whether the elements are less than or greater than the pivot.

Related: Python program for insertion sort

Program code for Quick Sort in Python

# Quick Sort in Python
def partition(arr, low, high):
    pivot = arr[high]
    i = low - 1
    for j in range(low, high):
        if arr[j] <= pivot:
            i += 1
            arr[i], arr[j] = arr[j], arr[i]
    arr[i + 1], arr[high] = arr[high], arr[i + 1]
    return i + 1
 
def quick_sort(arr, low, high):
    if low < high:
        pi = partition(arr, low, high)
        quick_sort(arr, low, pi - 1)
        quick_sort(arr, pi + 1, high)
 
arr = [10, 7, 8, 9, 1, 5]
quick_sort(arr, 0, len(arr) - 1)
print("Sorted array:", arr)

Explanation

1. Function Definitions: The partition function partitions the array into two sub-arrays based on the pivot element, and the quick_sort function sorts the array using the quick sort algorithm.
2. Main Program: The program defines an unsorted array and sorts it using the quick_sort function. It then prints the sorted array.

Output

• When you run the above program, it will sort the array using quick sort and print the sorted result.

Conclusion

• In this tutorial, we learned how to implement the quick sort algorithm in Python.
• Understanding this concept is essential for solving various sorting problems and enhancing your programming skills.