Java Code Challenges & Tips

1. Implement a function in Java that takes a string and returns the first non-repeating character.

2. Write a method to find the longest palindrome in a given string.

3. Create a function that merges two sorted arrays into a single sorted array.

4. Implement a LRU (Least Recently Used) Cache using Java collections.

5. Write a Java program to perform a binary search on a sorted array.

6. Design a class in Java that represents a basic calculator that can evaluate expressions in the format of "3 + 5" or "10 / 2".

7. Write a method that finds the intersection of two arrays and returns them as a new array.

8. Create a Java method that generates all possible subsets of a given set of integers.

9. Implement a function that checks if two strings are anagrams of each other.

10. Write a Java code to sort a linked list using merge sort.