15.1.3. Choosing a Pivot Element

Try these first

1. 1.

   What is a pivot element in Quick sort?

   Hint

   Think about how it helps divide the array.

2. 2.

   Name one advantage Quick sort has over merge sort.

   Hint

   Consider the space requirements.

3. 3.

   What is the main purpose of choosing a pivot in Quick sort?

   • To find the maximum
   • To divide the array for sorting
   • To merge the sorted parts

   Hint

   Recall how pivot partitioning works.

4. 4.

   True or False: Quick sort requires additional memory for merging.

   • True
   • False

   Hint

   Think about how merge sort works.

5. 5.

   Given the array [4, 2, 7, 3, 1, 6], implement the Quick sort algorithm using the first element as the pivot. Show the partitioning steps and the recursive calls.

   Hint

   Focus on how elements rearrange around the pivot and track recursive calls.

6. 6.

   Analyze the impact of selecting the last element as the pivot in a descending sorted array. How does it affect Quick sort’s performance?

   Hint

   Consider how you can balance the partitions to achieve better performance.