What is the pivot selection strategy in Quick Sort that can lead to poor perform
Practice Questions
Q1
What is the pivot selection strategy in Quick Sort that can lead to poor performance?
Random pivot
Median of three
First element
Last element
Questions & Step-by-Step Solutions
What is the pivot selection strategy in Quick Sort that can lead to poor performance?
Step 1: Understand what Quick Sort is. It is a sorting algorithm that works by selecting a 'pivot' element and partitioning the array around that pivot.
Step 2: Learn about the pivot selection. The pivot is used to divide the array into two parts: elements less than the pivot and elements greater than the pivot.
Step 3: Identify a common pivot selection strategy. One simple strategy is to always choose the first element of the array as the pivot.
Step 4: Consider the scenario where the array is already sorted or nearly sorted. If the first element is chosen as the pivot in this case, it will not effectively divide the array.
Step 5: Understand the consequence of poor pivot selection. When the pivot does not divide the array well, Quick Sort may end up making many recursive calls, leading to a time complexity of O(n^2).
Step 6: Conclude that choosing the first element as the pivot can lead to poor performance in specific cases, particularly with sorted or nearly sorted arrays.
