Basic Data Structure Interview Questions

What are Data Structures?
Why Create Data Structures?
What are some applications of Data structures?
Explain the process behind storing a variable in memory.
Can you explain the difference between file structure and storage structure?
Describe the types of Data Structures?
Difference between Array and Linked List.
Difference between an array and a list.
What is an asymptotic analysis of an algorithm?
What is hashmap in data structure?
What is the requirement for an object to be used as key or value in HashMap?
How does HashMap handle collisions in Java?
What is the time complexity of basic operations get() and put() in HashMap class?

Data Structure Interview Questions related Array

What is an array? What are the applications of arrays?
Explain different types of array data structure.
Can an array be resized at runtime?
What is the time complexity for accessing an element in an array?
How would you find the smallest and largest element in an array?
Explain the concept of a multi-dimensional array.
What is an array index out of bounds exception?
How would you reverse an array in-place in linear time and constant space?
Explain the concept of a jagged array.
How can you find duplicate elements in an array?
Discuss the advantages and disadvantages of using arrays.

Data Structure Interview Questions related Linked list

What is a linked list? What are the applications for the Linked list?
Explain different types of linked lists?
What are the advantage of Linked List?
What are the disadvantage of Linked List?
What is a cycle/loop in Singly Linked List.
What is time complexity of Linked List operations?
How would you compare Dynamic Arrays Vs Linked Lists? flexible and can represent complex data structures.

Data Structure Interview Questions related Stack

What is a stack ? What are the applications of stack ?
What are different operations available in stack data structure?
How is a stack implemented in an array?
What is the time complexity of stack operations?
What are the applications of a stack?
What is a stack overflow?
What is a stack underflow?
What is a postfix expression?
How can a stack be used to evaluate a postfix expression?
What is a prefix expression?
How can a stack be used to evaluate a prefix expression?
How can a stack be used to check if a parenthesis expression is balanced?
How do you implement stack using queues?

Data Structure Interview Questions related Queue

What is a Queue? What are the applications of queue?
What are different operations available in queue data structure?
How is a Queue implemented in an array?
How is a Queue implemented in a linked list?
What is the time complexity of enqueue and dequeue operations in a Queue?
What are the applications of Queues?
How do you handle overflow and underflow conditions in a Queue?
What is a circular queue?
What is a priority queue?
How is a priority queue implemented?
What is a double-ended queue (Deque)?
How is a deque implemented?
What are the advantages of using a Queue?
What are the disadvantages of using a Queue?
Differentiate between stack and queue data structure.
How to implement a queue using stack?

Data Structure Interview Questions related Heap Data Structure

What is a heap data structure?
What are the two types of heaps?
What is the time complexity of inserting an element into a heap?
What is the time complexity of deleting an element from a heap?
What is the time complexity of finding the minimum or maximum element in a heap?
What are the applications of heaps?
What is the difference between a heap and a binary search tree (BST)?
How do you convert a BST into a heap?
How do you merge two heaps?
What is the difference between a heap and a priority queue?
What are the advantages of using a heap?

Data Structure Interview Questions related Hash Data Structure

What is a hash data structure?
What is a hash table?
What is a hash function?
Explain how a hash function works.
What is a collision?
Describe different collision resolution techniques.
How are collisions handled in a hash data structure?
What is chaining?
What is open addressing?
What is separate chaining?
What are the trade-offs between open addressing and separate chaining?
What is cuckoo hashing?
What is the load factor of a hash table?
What is the optimal load factor for a hash table?
Explain the concept of load factor and its impact on performance.
What are the advantages of using a hash data structure?
What are the disadvantages of using a hash data structure?
Explain bloom filters and their applications.

Data Structure Interview Questions related Tree Data Structure

What is a Tree?
Explain different types of trees.
What are the basic operations performed on a tree?
What are the different ways to represent a tree in memory?
What are the advantages and disadvantages of using trees?
When would you choose a tree over other data structures like arrays or linked lists?
Explain the concept of a binary search tree.
How do self-balancing trees like AVL or Red-Black trees work?
Describe the different tree traversal methods (preorder, inorder, postorder).
How can you convert a binary search tree into a sorted array?
Explain the concept of a minimum spanning tree.
Describe the use of trees in real-world scenarios.

Data Structure Interview Questions related Graph

What is a graph?
Explain common graph representations.
Differentiate between directed and undirected graphs.
Describe common graph types.
Discuss time and space complexity of basic graph operations.
Explain Dijkstra’s algorithm and its applications.
Compare DFS and BFS algorithms. strengths, weaknesses, and use cases.
Describe topological sorting. algorithm and applications.
Explain minimum spanning trees. algorithms and their significance.

Advance Data Structure Interview Questions

What is binary tree data structure? What are the applications for binary trees?
What is binary search tree data structure? What are the applications for binary search trees?
What are tree traversals?
What is a deque data structure and its types? What are the applications for deque?
What are some key operations performed on the Deque data structure?
What is a priority queue? What are the applications for priority queue?
Compare different implementations of priority queue
What is the difference between the Breadth First Search (BFS) and Depth First Search (DFS)?
What is AVL tree data structure, its operations, and its rotations? What are the applications for AVL trees?
What is a B-tree data structure? What are the applications for B-trees?
Define Segment Tree data structure and its applications.
Define Trie data structure and its applications
Define Red-Black Tree and its applications
Which data structures are used for implementing LRU cache?