Mock tests
Timed papers with a real clock, instant scoring, and a breakdown afterwards showing which topics cost you the marks. Retake anything as often as you like.
51 papers · 640 questions · 30 free, 21 with Pro · no negative marking
You can sit any free paper without an account. Signing up is what saves the score, ranks you and pays coins.
Computer Science Core 10 papers
Complexity, data structures, sorting, DBMS, OS and networks.
Data Structures & Algorithms — Core Concepts
Complexity, sorting properties and the behaviour of stacks, queues, linked lists, trees and hash tables — the theory questions that open most placement tests.
Start the testOOP & DBMS — Interview Fundamentals
The object-oriented ideas and database basics that come up in almost every campus interview: inheritance, polymorphism, normalisation, keys, joins and ACID.
Start the testTime & Space Complexity Analysis
Work out the exact asymptotic time and space cost of loops, recurrences and standard operations.
Start the testArrays & Strings — Algorithms and Complexities
Standard array and string techniques - two pointers, prefix sums, Kadane, rotation - and what each one actually costs.
See what is insideLinked Lists, Stacks & Queues
Costs of linked-list operations and hand-traces of stack and queue behaviour, including postfix evaluation.
Start the testTrees, BST, Traversals & Heaps
Trace binary tree traversals, reason about BST properties and heap operations, and count nodes.
See what is insideGraphs — BFS, DFS & Shortest Paths
Trace breadth-first and depth-first search, run Dijkstra by hand, and reason about graph representations.
Start the testSorting & Searching Properties
Hand-trace sorting passes and pin down stability, in-place behaviour and best/average/worst-case costs.
See what is insideDBMS — SQL Semantics, Joins, Keys & Normalisation
Evaluate SQL against small given tables (including NULL traps) and answer on keys, normal forms and ACID.
Start the testOperating Systems & Computer Networks
Scheduling calculations, memory management and deadlock, plus the OSI/TCP-IP model and core protocols.
See what is insideHow to use these
A drill is about a dozen questions on one topic — good for a spare fifteen minutes between classes. A full paper is forty questions in an hour and should be sat in one go, with the phone somewhere else.
There is no negative marking here, so never leave a question blank. A guess on a four-option question is worth a quarter of a mark on average; a blank is worth zero.
The score is the least useful part of the result. The topic breakdown underneath it is the part that tells you what to revise tonight.