In C please

2.1 Design a brute force algorithm to solve the convex-hull problem and analyze its efficiency.

2.2 Design a recursive divide-and-conquer algorithm of (n log n) to solve the convex-hull problem, set up a recurrence to analyze the number of executions of the basic operation of the best case, and determine the efficiency class. Use the Master Theorem to verify the efficiency class in your analysis result.

2.3 Implement the two algorithms and test them using data 2.txt, which includes 30,000 points (pairs of x-y coordinates). Your programs are required to display the number of points on the convex hull and their x-y coordinates (sorted by their x coordinates). Your programs are also required to display execution time. Compare the differences in execution time and theoretical analysis.