1. Write a function to find the majority element in an array.

2. Implement a function to find the kth smallest element in an array.

3. Write a function to find the kth largest element in an array.

4. Implement a function to find the first repeating element in an array.

5. Write a function to find the first non-repeating element in an array.

6. Implement a function to find the subarray with the maximum sum.

7. Write a function to find the length of the longest subarray with a given sum.

8. Implement a function to find the number of subarrays with a given sum.

9. Write a function to find the maximum sum of a subarray of size k.

10. Implement a function to find the maximum sum of a circular subarray.

11. Write a function to find the maximum product of a subarray.

12. Implement a function to find the longest increasing subarray.

13. Write a function to find the longest decreasing subarray.

14. Implement a function to find the longest subarray with equal number of 0s and 1s.

15. Write a function to find the longest subarray with all distinct elements.

16. Implement a function to find the longest subarray with a given number of distinct elements.

17. Write a function to find the longest subarray with all elements having at most k distinct elements.

18. Implement a function to find the maximum length of a subarray with the sum of elements divisible by k.

19. Write a function to find the longest contiguous subarray with at least one 0.

20. Implement a function to find the length of the smallest subarray with a sum greater than or equal to a given value.

21. Write a function to find the longest subarray where the difference between the maximum and minimum elements is at most k.

22. Implement a function to find the maximum length of a subarray with the sum of elements equal to a given value.

23. Write a function to find the maximum length of a subarray with the product of elements equal to a given value.

24. Implement a function to find the longest subarray with a given sum and all elements are positive.

25. Write a function to find the longest subarray with a given sum and all elements are non-negative.

26. Implement a function to find the longest subarray with a given sum and all elements are negative.

27. Write a function to find the maximum length of a subarray with the product of elements equal to a given value.

28. Implement a function to find the maximum length of a subarray with the product of elements divisible by k.

29. Write a function to find the longest subarray with a given sum and all elements are distinct.

30. Implement a function to find the longest subarray with a given sum and all elements are same.