1. Implement the merge sort algorithm and analyze its time complexity.
2. Write a function to sort an array using the quick sort algorithm, and discuss its average and worst-case time complexities.
3. Given two sorted arrays, merge them into a single sorted array using a divide and conquer approach.
4. Use binary search to find the square root of a given number with a precision of 0.01.
5. Implement a function that finds the k-th smallest element in an unsorted array using a divide and conquer approach.
6. Write a function to find the majority element in an array (the element that appears more than n/2 times) using a modified divide and conquer approach.
7. Given an array of integers, count the number of inversions using the merge sort technique.
8. Use the divide and conquer technique to find the closest pair of points in a 2D space.
9. Write a function that solves the "maximum subarray problem" using divide and conquer.
10. Implement Strassen's algorithm to multiply two matrices, and analyze its complexity.
11. Given a list of points, find the convex hull using the divide and conquer approach.
12. Write a function to find the longest common subsequence (LCS) between two strings using divide and conquer.
13. Implement a function that finds the maximum product of three integers in an array using a divide and conquer strategy.
14. Given a matrix, find the maximum sum rectangle using the divide and conquer technique.
15. Write a function to find the median of two sorted arrays in logarithmic time.
16. Implement a function that finds all unique paths in a grid with obstacles using divide and conquer.
17. Use divide and conquer to find the longest palindromic substring in a given string.
18. Given an array, determine if it can be partitioned into two subsets with equal sum using divide and conquer.
19. Write a function to find the number of unique ways to climb stairs when each step can be 1, 2, or 3 steps at a time.
20. Implement a function to count the number of ways to tile a 2 x n rectangle using 1 x 2 dominoes.
21. Given a binary tree, find its diameter using a divide and conquer approach.
22. Write a function to find the longest increasing subsequence in an array using divide and conquer.
23. Implement a function to determine if a string is a valid anagram of another string using divide and conquer.
24. Given an array of stock prices, find the maximum profit that can be made by buying and selling once using a divide and conquer strategy.
25. Write a function to find the longest substring with at most k distinct characters using a divide and conquer approach.
26. Use divide and conquer to compute the product of two polynomials represented as arrays.
27. Implement a function to find the smallest number in a rotated sorted array using binary search.
28. Given a string, count the number of distinct palindromic substrings using divide and conquer.
29. Write a function to find the longest common prefix of a list of strings using a divide and conquer approach.
30. Given an unsorted array, find the median value using the QuickSelect algorithm.
31. Implement a function to determine if a number is a perfect square using binary search.
32. Write a function to find the number of unique paths in a grid with obstacles using dynamic programming and divide and conquer.
33. Given a list of intervals, merge all overlapping intervals using a divide and conquer approach.
34. Use divide and conquer to count the number of ways to partition a number into sums of positive integers.
35. Write a function to find the first missing positive integer in an unsorted array using divide and conquer.
36. Implement a function that uses divide and conquer to reverse a linked list.
37. Given two arrays, find their intersection using a divide and conquer strategy.
38. Write a function to find the maximum sum of a subarray with a fixed length using divide and conquer.
39. Given a binary search tree, find the lowest common ancestor of two nodes using divide and conquer.
40. Implement a function to calculate the longest path in a binary tree using divide and conquer.