📌 Introduction
If you’re preparing for campus placements or aiming for product-based companies like Amazon, Microsoft, or Google, one thing is certain: you will be tested on DSA (Data Structures and Algorithms).
But here’s the big question students ask:
👉 “Which DSA topics are most commonly asked in coding interviews?”
Let’s break it down by core topics and company-level expectations.
🧩 Core DSA Topics Asked in Almost Every Interview
1. Arrays & Strings
Most basic but heavily used in interviews.
Typical problems:
Reverse an array
Kadane’s Algorithm (maximum subarray sum)
Rotate array/string
Check palindrome / anagram
2. Linked List
Common for testing understanding of pointers and dynamic memory.
Typical problems:
Reverse a linked list
Detect a cycle (Floyd’s algorithm)
Merge two sorted linked lists
3. Stack & Queue
Popular in both service-based and product-based interviews.
Typical problems:
Balanced parentheses
Next greater element
Implement queue using stacks
4. Hashing
Tested for fast lookups and problem-solving ability.
Typical problems:
Two Sum Problem
Count frequencies of elements
Subarray with given sum
5. Trees
Binary Trees and Binary Search Trees (BST) are favorites in product-based companies.
Typical problems:
Level order traversal
Lowest Common Ancestor (LCA)
Height of a tree
6. Graphs
More common in product-based interviews.
Typical problems:
BFS & DFS traversal
Shortest Path (Dijkstra, Bellman-Ford)
Detect cycle in a graph
7. Dynamic Programming (DP)
The toughest yet most rewarding topic.
Typical problems:
Fibonacci sequence (memoization & tabulation)
Longest Common Subsequence
0/1 Knapsack problem
Coin change problem
8. Searching & Sorting Algorithms
Classic questions to test efficiency.
Typical problems:
Binary Search
Merge Sort & Quick Sort
Search in rotated sorted array
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