What the board asks
We went through the ISC board papers, question by question, and matched each question to a topic. Here is what was asked, how often, and what was never asked.
Computer Science: 180 topics in the 2027 syllabus, across 10 units. The board has asked 117 of them at least once. 63 were never asked in the papers we checked.
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CS10 Complexity and Big O Notation
All the topics in Computer Science: Complexity and Big O Notation
Asked topics first, the most asked at the top. Tap a topic to see what to write, the result, the years, and the real board questions.
9 topics shown
| # | Topic | Type | Marks | Times asked | Last asked | Status |
|---|---|---|---|---|---|---|
| 1 | Big O of sequential and nested loopsCount how often the innermost statement runs for loops one after another (add) and loops inside loops (multiply), write the total in terms of the given bounds, and give the Big O, including the case when all bounds equal N. | Sum | 1 | 3 papers | 2025 improvement | Asked |
| 2 | Big O of dependent and halving or doubling loopsFind the Big O of a nested loop whose inner bound depends on the outer counter (1 + 2 + ... + n) and of a loop whose counter is doubled or halved each pass. | Sum | 1 | 1 paper | 2026 | Asked |
| 3 | Dominant term and dropping constantsExplain with an example such as 3n^2 + 5n + 7 that for large n the highest-order term decides the growth, so constants and lower terms are dropped to give O(n^2). | Give reason | 2 | 1 paper | 2024 | Asked |
| 4 | Best and worst case Big O of searching and sortingState the best, average and worst case Big O of linear search, binary search, bubble sort, selection sort and insertion sort, with the input that causes each case. | Statement | 2 | 1 paper | 2020 | Asked |
| 5 | Compare growth rates such as O(n^2) and O(2^n)Arrange or compare common orders O(1), O(log n), O(n), O(n log n), O(n^2), O(n^3), O(2^n), say which is better for large n and why, with a value of n to show it. | Comparison | 2 | 1 paper | 2019 | Asked |
| 6 | Define complexity and Big O; factors of complexityDefine computational complexity (time and space) and Big O notation, and state that complexity is measured as a function of the input size n, naming time and space as the two factors. | Statement | 2 | 1 paper | 2018 | Asked |
| 7 | Best, average and worst caseDefine best, average and worst case of an algorithm and illustrate each with linear search (target first, in the middle on average, last or absent). | Statement | 1 | never | Never asked | |
| 8 | Complexity of code that calls methodsFind the Big O when a loop calls a method whose own complexity is known (multiply) or when methods are called one after another (add), and state the overall order. | Sum | 1 | never | Never asked | |
| 9 | Complexity of matrix and linear-equation algorithmsGive and justify the Big O of matrix addition, matrix multiplication and solving n linear equations by elimination by counting the nested loops. | Sum | 1 | never | Never asked |
This list was made from the 2027 syllabus and checked with 9 board papers, including the 2027 specimen paper. It is not yet checked with the textbook.
The 10 topics Computer Science papers ask most
Counted on the board papers from 2018 to the 2027 specimen paper, which every unit has been checked against.
- 1.Principle of duality: state it and write the dualCS1 Boolean Algebra · asked 8 times since 2018
- 2.Complement of an expression using De Morgan's theoremCS1 Boolean Algebra · asked 8 times since 2018
- 3.Word problem to truth table and SOP or POSCS1 Boolean Algebra · asked 8 times since 2018
- 4.K-map reduction of a four-variable POS expressionCS1 Boolean Algebra · asked 8 times since 2018
- 5.Pre-order, in-order and post-order traversalCS9 Data Structures · asked 8 times since 2018
- 6.K-map reduction of a four-variable SOP expressionCS1 Boolean Algebra · asked 7 times since 2018
- 7.Read a tree: leaves, internal nodes, parent, siblings, degreeCS9 Data Structures · asked 7 times since 2018
- 8.Truth table to classify tautology, contradiction or contingencyCS1 Boolean Algebra · asked 6 times since 2018
- 9.Convert between cardinal and canonical formsCS1 Boolean Algebra · asked 6 times since 2018
- 10.Address of an element, row major and column majorCS6 Arrays and Strings · asked 6 times since 2018