Anyone can help me to solve this question, I have tryed, but didn't work with me

Question

https://code.sololearn.com/cA10a2237A0A/?ref=app
Assume we want to analyze empirically 4 variants of the Quicksort algorithm by varying the
selection of the pivot and the recursive call as follows:
● Try the following values when selecting a pivot:
- Pick the last element as pivot
- Pick a random element as pivot
● Do not make a recursive call to QuickSort when the list size falls below a given
threshold, and use Insertion Sort to complete the sorting process instead. Try the
following values for the threshold size:
- Log2(N)
- Sqrt(N)
Therefore, you are asked:
a. Write the java code for the 4 Quicksort implementations.
b. Write a driver program that allows you to measure the running time in
milliseconds of the 4 implementations for N = 10000, 20000, 40000, 80000 and 160000.
For each data size N, generate a random list of N random integers ranging from 1 to 107
and use the same list to measure the running

Answer 1

Their is one extra Curly brackt remove last one

Answer 2

also add
import java.util.Random;
and after for() in main() one } bracket is missing