Introduction

Quick Sort Technique: Quick Sort is an efficient, comparison-based sorting algorithm that follows the divide-and-conquer strategy. The algorithm selects a "pivot" element, partitions the array around the pivot, and recursively applies the same process to the subarrays.
This technique gets its name because it sorts elements by quickly partitioning them relative to the pivot.

How can we sort an array?

• In Quick Sort, we select a "pivot" element from the array.
• Partition the array into two subarrays:
  • Elements smaller than the pivot go into the left subarray.
  • Elements larger than the pivot go into the right subarray.
• Recursively apply the same steps to the left and right subarrays.
• Combine the sorted subarrays and pivot to form the final sorted array.

Important Observations

• The choice of the pivot element greatly affects the efficiency of the algorithm.
• Partitioning is performed in-place, minimizing the need for additional memory.
• The array will be sorted in ascending order after the recursive process is complete.

Key Characteristics:

• Divide-and-conquer sorting technique.
• In-place sorting algorithm; no additional memory required for partitioning.
• Highly efficient for large datasets.

Advantages:

• Efficient for large datasets.
• Time complexity is (O(n log n)) on average.
• Requires minimal additional memory.

Disadvantages:

• Worst-case time complexity is (O(n^2)), which occurs when the pivot is poorly chosen.
• Not a stable sorting algorithm (does not preserve the order of equal elements).

Time Complexity:

• Best Case: (O(n log n)).
• Average Case: (O(n log n)).
• Worst Case: (O(n^2)).