Big O Notation is essentially a measure of the performance/complexity of an algorithm, also known as the time complexity of an alogrithm. There are 5 main notations: Constant, Linear, polynomial, Exponential and Logarithmic. Constant has a time complexity of O(1). This means it has a constant execute time no matter the size of the input …
Author Archives: jamieho123
Karnaugh Map
Boolean expressions describe electric circuits in computer systems and selection statements in programming. We use logic gates to picture these electric circuits. It is important to use as few expressions (gates/electric components) as possible to: Reduce size of circuit. Reduce manufacture cost. Reduce power consumption. Execute instructions as quickly as possible by reducing need to …
Simplifying Boolean Expressions
General Rules for AND and OR: AND: Both terms have to be 1, or TRUE, for the result to be 1, or TRUE. OR: Only 1 term has to be 1, or TRUE, for the result to be 1, or TRUE. Rule 1: De Morgan’s Law Rule 2: Distribution Rule 3: Association Rule 4: Commutation …
1.3.3 Networks
A computer network is a group of computers that use a set of communication protocols for the purpose of sharing resources. Network topologies: Network topology refers to the physical arrangement of the components in a network. The network topology used will affect the cost, performance and ease of installation of a network. Bus topology: In …
1.2.4: Modes of addressing
Immediate Addressing: The instruction contains the data to be used. E.g: ADD 6 (add value 6 to accumulator) This is the fastest method as it doesn’t involve having to go the the main memory. Useful for carrying out instructions on constants opposed to variables. Direct (or absolute) addressing: The instruction points directly to a location …
1.2.4 Types of Programming Languages
Programming Paradigms: We need to know 3 types of paradigms: Procedural, Object Orientated and Assembly. Procedural: Languages such as Python and C. Common characteristics of procedural programming: Instructions given in sequence Selection is used to make choices/branch out Iteration decides how many times something is done Programs often broken down into Procedures/functions Object Orientated: Languages …
2.2.1: Programming Techniques
Integrated Development Environment, IDE: An IDE is software that enables you to enter, edit, compile and run programs. Many also have debugging faclities to help find errors. Debugging facilities include: Set a breakpoint which will stop the program on that line. Set a watch on a variable so its value is displayed when it changes. …
OOP Course Notes
Week 1: What an object is and how we can use objects in a program. We know that objects come from a class, which is like a blueprint, and that we can customise the attributes of an object as well as call methods on it. Each object starts with the same attributes, but we can …
1.4.2: Data Structures
Data Structure – This is a way of representing/organizing data held in a computer’s memory to be used efficiently. Data structures fall under 2 categories: Static or dynamic. Static: The size is set at the beginning of the program when it compiles and can not be changed. This is very limiting and inefficient as you …
Software Methodologies
Software development life cycle (SDLC)- The process of developing software with high quality with low cost and time. Different Methodologies: Waterfall Method: This was the first process model to be introduced. It is a simple and easy to use process, which is recommended for smaller projects. 6 Stages to the Waterfall Method: Requirements, Design, Development, …
Computer Science Notes 