Java Collections Coding Practice Problems

Java Collections provides dynamic and efficient data structures for handling and processing data. This collection of Java practice problems covers fundamental concepts of ArrayLists, LinkedLists, Stacks, Queues, Deques, PriorityQueues, HashMaps, and TreeSets, helping you master data manipulation, searching, sorting, and advanced operations.

Whether you are a beginner or looking to enhance your problem-solving skills, these exercises will build a strong foundation in Java Collections.

Java Collections Practice Questions

Basic:

• ArrayList Insertion
• ArrayList Operations
• ArrayList Iterate Front to Back
• Average of an ArrayList
• Check Sorted ArrayList
• Max and Min In ArrayList
• Get Smaller Elements
• ArrayList Separate Even Odd
• LinkedList Insertion
• LinkedList Traversal
• Stack Designer
• Operations on Stack
• Queue Operations
• Queue Traversal
• Queue Reversal
• Deque Implementations
• Insertion in Deque
• Dequeue Traversal
• Deque Deletion
• Rotate Deque By K
• PriorityQueue Insertion - 1
• PriorityQueue Insertion - 2
• HashMap Operations
• TreeSet Operations
• TreeMap Operations
• Fill LinkedList

Easy:

• Minimum Vertical Sum
• Maximum Neighbours In ArrayList
• LinkedList Josephus Circle
• Delete Mid of a Stack
• Removing Consecutive Duplicates
• Removing Consecutive Duplicates - 2
• Parenthesis Checker
• Shopkeeper Profit
• Get Min at Pop
• Queue using Two Stacks
• Reverse First K Elements of Queue
• Generate Binary Numbers
• K Sized Subarray Maximum
• Operations on PriorityQueue
• Hashing for Pair - 1
• Hashing for Pair - 2
• Union of Arrays with Duplicates
• Unique Substrings
• Intersection of Arrays with Distinct
• Distinct Sorted
• Print Different Characters in Sorted Manner
• Elected Candidate
• Tie Breaker
• Frequency Count
• Count Non-Repeated Elements
• First Repeating Element
• Subarray with 0 Sum
• Sorted Frequency
• Common Elements
• Sort an ArrayList
• Are LinkedLists Equal

Medium:

• Maximize Number of Toys
• Minimum Cost of Ropes
• Kth Largest Element
• Kth Smallest Element
• Rotate LinkedList By K

This set of practice questions covers everything from basic operations on ArrayLists and LinkedLists to more advanced topics like priority queues and hashing. Whether you're just starting out or want to sharpen your problem-solving skills, these exercises will help you get comfortable with essential data structures.