STUDY MATERIAL · GATE CS · DA
GATE Data Structures and Algorithms: questions and notes
Data Structures and Algorithms questions from 13 GATE papers (2018–2026) with the official answers, 114 of 117 solved step by step, plus notes for each topic, a formula sheet and practice questions.
- previous-year questions
- 117previous-year questions
- solved step by step
- 114solved step by step
- GATE papers, 2018–2026
- 13GATE papers, 2018–2026
- topics with notes
- 7topics with notes
TOPICS
Seven topics, in the order they are taught
Taken from the official GATE 2027 syllabus. Each topic has notes, the formulas you need, its previous-year questions with the official answers, most of them solved step by step, and practice questions.
Arrays, stacks, queues and linked lists
GATE CS/IT notes on arrays, stacks, queues and linked lists.
13 previous-year questions · 20 marks · 6 practice questions
Trees, binary search trees and binary heaps
Trees, binary search trees and binary heaps: how hierarchical data is structured, searched and prioritised.
26 previous-year questions · 38 marks · 7 practice questions
- GATE CS only
Asymptotic complexity and recurrences
Asymptotic complexity describes how an algorithm's time and space grow with input size n, independent of any machine.
14 previous-year questions · 19 marks · 6 practice questions
Searching, sorting and hashing
Searching, sorting and hashing cover how to find, order and index data.
18 previous-year questions · 23 marks · 5 practice questions
Greedy, dynamic programming and divide-and-conquer
Greedy, dynamic programming and divide-and-conquer are the three core algorithm-design paradigms for GATE CS.
8 previous-year questions · 13 marks · 6 practice questions
Graphs: traversals, minimum spanning trees and shortest paths
Graph traversal (BFS, DFS with timestamps and edge classification), ordering and connectivity (topological sort, connected and strongly connected components), minimum spanning trees (Kruskal, Prim, cut and cycle properties) and shortest paths (BFS, DAG relaxation, Dijkstra, Bellman-Ford, Floyd-Warshall): the exact procedures, the conditions under which each algorithm is correct, and their time and space costs, with hand-traced worked examples and original practice problems.
28 previous-year questions · 53 marks · 5 practice questions
- GATE DA only
Programming in Python
Python for GATE DA is tested as exact-output tracing: you read a short program and say what it prints.
10 previous-year questions · 18 marks · 6 practice questions
QUESTIONS BY TOPIC AND YEAR
117 questions, by topic and year
How many questions each topic had in the CS and DA papers of each year. This shows what was asked, not what will be asked. We placed each question under a topic ourselves; the exam paper does not label topics. Every question links back to its paper.
| Topic | 2018 | 2020 | 2022 | 2023 | 2024 | 2025 | 2026 | Total |
|---|---|---|---|---|---|---|---|---|
| Linear structures | 1 | 1 | 2 | 2 | 3 | 2 | 2 | 13 |
| Trees & heaps | 2 | 4 | 1 | 2 | 5 | 5 | 7 | 26 |
| Complexity | · | 1 | 2 | 2 | 3 | 2 | 4 | 14 |
| Sorting & hashing | · | 1 | 1 | 1 | 3 | 7 | 5 | 18 |
| Design techniques | 2 | · | · | 1 | 3 | · | 2 | 8 |
| Graph algorithms | 2 | 3 | 1 | 1 | 6 | 8 | 7 | 28 |
| Python | · | · | · | · | 3 | 3 | 4 | 10 |
GATE CSE question papers with solutions: 2026 Set 1, 2026 Set 2, 2025 Set 1, 2025 Set 2, 2024 Set 1, 2024 Set 2, 2023, 2022, 2020, 2018
For CS, the 2019 and 2021 papers are not included: the copies we host are scans. GATE 2023 comes from IIT Kanpur's own copy of the paper and its answer key, which numbers the CS questions Q.11 to Q.65. For 2024, 2025 and 2026 both sessions (CS1 and CS2) are included. For DA, all three papers are included: 2024 (IISc Bengaluru), 2025 (IIT Roorkee) and 2026 (IIT Guwahati), each with its final answer key.
Data Structures and Algorithms formulas by topic
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THE OFFICIAL SYLLABUS
What each paper lists under Data Structures and Algorithms
From the GATE 2027 syllabus PDF: the data-structure items of CS Section 4, “Programming and Data Structures”, and all of CS Section 5, “Algorithms”. Programming in C and recursion, the first two items of Section 4, are on the Programming in C page. For DA, all of Section 4, “Programming, Data Structures and Algorithms”, including Programming in Python, the topic only DA lists.
GATE CS
Arrays, stacks, queues, linked lists, trees, binary search trees, binary heaps, graphs. … Searching, sorting, hashing. Asymptotic worst case time and space complexity. Algorithm design techniques: greedy, dynamic programming and divide‐and‐conquer. Graph traversals, minimum spanning trees, shortest paths.
GATE DA
Programming in Python, basic data structures: stacks, queues, linked lists, trees, hash tables; Search algorithms: linear search and binary search, basic sorting algorithms: selection sort, bubble sort and insertion sort; divide and conquer: mergesort, quicksort; introduction to graph theory; basic graph algorithms: traversals and shortest path.
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