Computer Fundamentals and Programming
What this domain tests
Questions cover number systems, computer organisation basics, C programming, algorithms, data structures, operating-system ideas, and networking fundamentals. The level is introductory, but precision on syntax and number representation matters.
Core concepts
- Binary, octal, decimal, and hexadecimal conversions are routine. In 2's complement, negate a number by inverting bits and adding 1.
- C data types include int, float, char, and double. Operators have precedence: postfix, unary, multiplicative, additive, relational, logical, assignment. Integer division truncates toward zero.
- Arrays use zero-based indexing. A function receives arguments by value in C unless pointers are used. A pointer stores an address.
- An algorithm is a finite sequence of steps; flowcharts show control flow. Common data structures include arrays, stacks, queues, linked lists, and trees.
- An operating system manages processes, memory, files, and I/O. A LAN connects devices in a limited area; an IP address identifies a network interface.
Worked example
Binary 1101₂ equals 1×8 + 1×4 + 0×2 + 1×1 = 13 in decimal. In an 8-bit 2's complement system, the 2's complement of 00001100 is 11110011 + 1 = 11110100.
Traps
Do not confuse assignment = with comparison ==. Array index 0 is valid; index n is out of bounds for an n-element array. Integer division 5/2 gives 2, not 2.5. A pointer is not the same as the value it points to.
Key points
- 1101₂ = 13₁₀.
- 2's complement: invert bits and add 1.
- Arrays are zero-indexed.
- C passes arguments by value by default.
- Precedence: multiplicative before additive.