Practice Collections in Java

Collections exercises

1. ArrayList Basics Java exercise — Create and use ArrayList
2. HashSet Basics Java exercise — Use HashSet for unique elements
3. HashMap Basics Java exercise — Store key-value pairs
4. List Iteration Methods Java exercise — Different ways to iterate a list
5. Queue Operations Java exercise — Use Queue for FIFO operations
6. Stack Operations Java exercise — Use Stack for LIFO operations
7. Word Frequency Counter Java exercise — Count word frequencies in a sentence
8. Remove Duplicates from List Java exercise — Remove duplicates while preserving order
9. List Intersection Java exercise — Find common elements between two lists
10. Sort Map by Value Java exercise — Sort a map by its values
11. Group By Property Java exercise — Group elements by a property
12. Simple LRU Cache Java exercise — Implement a simple LRU cache
13. Priority Queue with Custom Order Java exercise — Use PriorityQueue with custom comparator
14. Two Sum with HashMap Java exercise — Find pair with target sum using HashMap
15. First Unique Element Java exercise — Find first element that appears once
16. Merge K Sorted Lists Java exercise — Merge multiple sorted lists into one
17. Stack Using Queues Java exercise — Implement a stack using only queues
18. Group Anagrams Java exercise — Group words that are anagrams of each other
19. Sliding Window Maximum Java exercise — Find maximum in each sliding window
20. Top K Frequent Elements Java exercise — Find the k most frequent elements
21. Merge Intervals Java exercise — Merge overlapping intervals
22. Task Scheduler Java exercise — Find minimum time to complete all tasks with cooldown