100 Best Data Structure and Algorithms (DSA) Interview Questions

Embarking on the journey to land your dream tech job? You’re in the right place. Our “Top 100 Data Structure and Algorithms DSA Interview Questions Topic-wise” guide is tailored to help you navigate through the most common and challenging questions you might encounter. Let’s boost your confidence and ensure you’re interview-ready!

Why Focus on Data Structures and Algorithms (DSA)?

Data Structures and Algorithms are the building blocks of computer science. They are critical in designing efficient software and are a favourite topic among interviewers to assess a candidate’s problem-solving skills.

The top 100 questions will revolve around these topics.

¡》Array and String Questions

1. How do you reverse an array in place?

2. What is the most efficient way to concatenate strings in Java?

¡¡》Linked List Questions

1. Can you explain how to detect a cycle in a linked list?

2. What are the advantages of using a doubly-linked list over a singly-linked list?

¡¡¡》Stack and Queue Questions

1. How would you implement a queue using two stacks?

2. What real-world scenarios can be modelled with a stack?

¡V》Tree and Graph Questions

1. Describe the algorithm for a depth-first search on a binary tree.

2. What is the difference between a tree and a graph data structure?

V 》Sorting and Searching Questions

1. When would you use merge sort over quicksort?

2. How does binary search work, and why is it efficient?

》Advanced DSA Questions

1. Explain the concept of dynamic programming with an example.

2. How do hash tables handle collisions?

V¡¡》Behavioural Questions

1. Describe a time when you optimized an algorithm.

2. How do you approach learning a new data structure or algorithm?

The top 100 DSA Interview Questions

Here a Are the links to top 100 DSA Interview Questions. Remember these questions are segregated based on the data structures and algorithms used to solve them. So let’s get started.

1. DSA Interview Questions on Array

  • Check if pair with the given Sum exists in Array
  • Best Time to Buy and Sell Stock
  • Find duplicates
  • Product of Array Except Self
  • Maximum Subarray
  • Maximum Product Subarray
  • Find Minimum in Rotated Sorted Array
  • Search in Rotated Sorted Array
  • 3 Sum
  • Container With Most Water
  • Find the Factorial of a large number
  • Trapping Rain Water
  • Chocolate Distribution Problem
  • Insert Interval
  • Merge Intervals
  • Non-overlapping Intervals

2. DSA Interview Questions on Matrix

  • Set Matrix Zeroes
  • Spiral Matrix
  • Program to find the transpose of a matrix
  • Word Search

3. DSA Interview Questions on String

  • Longest Substring Without Repeating Characters
  • Longest Repeating Character Replacement
  • Smallest window in a String containing all characters of other String
  • Check whether two Strings are anagram of each other
  • Print all anagrams together
  • Check if given Parentheses expression is balanced or not
  • Sentence Palindrome
  • Longest Palindromic Substring
  • Palindromic Substrings
  • Longest Common Prefix

4. DSA Interview Questions on Linked List

  • Reverse a Linked List
  • Detect Cycle in a Linked List
  • Merge Two Sorted Lists
  • Merge K Sorted Lists
  • Remove Nth Node From End Of List
  • Reorder List
  • Add 1 to a number represented as linked list
  • Find the middle of a given linked list
  • Delete last occurrence of an item from linked list

5. DSA Interview Questions on Stack & Queue

  • Convert Infix expression to Postfix expression
  • Next Greater Element
  • Delete middle element of a stack
  • Check mirror in n-ary tree
  • The Celebrity Problem
  • Length of the longest valid substring
  • Print Right View of a Binary Tree
  • Find the first circular tour that visits all petrol pumps

6. DSA Interview Questions on Tree

  • Maximum Depth of Binary Tree
  • Check if two trees have same structure
  • Invert/Flip Binary Tree
  • Binary Tree Maximum Path Sum
  • Binary Tree Level Order Traversal
  • Serialize and Deserialize Binary Tree
  • Subtree of Another Tree
  • Construct Binary Tree from Preorder and Inorder Traversal
  • Validate Binary Search Tree
  • Kth Smallest Element in a BST
  • Lowest Common Ancestor of BST
  • Implement Trie (Prefix Tree)
  • Add and Search Word

7. DSA Interview Questions on Heap

  • Top K Frequent Elements
  • Find Median from Data Stream
  • Largest triplet product in a stream
  • Connect n ropes with minimum cost

8. DSA Interview Questions on Graph

  • Clone Graph
  • Course Schedule
  • Pacific Atlantic Water Flow
  • Number of Islands
  • Longest Consecutive Sequence
  • Snake and Ladder Problem
  • Detect Cycle in a Directed Graph
  • Bridges in a graph
  • Check whether a given graph is Bipartite or not
  • Find size of the largest region in Boolean Matrix
  • Flood fill Algorithm
  • Strongly Connected Components
  • Topological Sorting

9. DSA Interview Questions on Dynamic Programming

  • Count ways to reach the n’th stair
  • Coin Change
  • 0/1 Knapsack Problem
  • Longest Increasing Subsequence
  • Longest Common Subsequence
  • Word Break Problem
  • Dice Throw
  • Egg Dropping Puzzle
  • Matrix Chain Multiplication
  • Combination Sum
  • Subset Sum Problem
  • Find maximum possible stolen value from houses
  • Count Possible Decodings of a given Digit Sequence
  • Unique paths in a Grid with Obstacles
  • Jump Game
  • Cutting a Rod
  • Maximum Product Cutting
  • Count number of ways to cover a distance

10. DSA Interview Questions on Bit Manipulations

  • Number of 1 Bits
  • Counting Bits
  • Missing Number
  • Reverse Bits
  • Find XOR of all subsets of a set

These are the top 100 DSA Interview Questions. Practice them to equip your self with DSA.


Congratulations on making it through our “Top 100 Data Structure and Algorithms DSA Interview Questions Topic-wise” guide. Remember, understanding the concepts is just the beginning.

Practice is key to mastering DSA, so dive into coding challenges, and don’t be afraid to tackle problems from different angles. Good luck with your interviews, and may your code always compile on the first try.


  • Data Structures Tutorial and Learning Path: A Comprehensive Guide
  • Algorithms in DSA Tutorial & Learning Path: Unlocking the Power of Efficient Problem-Solving
  • Common Data Structure Interview Questions & Answers
  • Frequently Asked Questions on Algorithms in Interviews and Answers

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