Algorithms

An algorithm is a finite, ordered set of well-defined instructions that offer a solution to a particular problem. It can have one or more inputs and might produce more than one output.
Algorithms operate in stages. These stages, or steps, are clearly defined so that they can be followed one at a time in a singular sequence, and performed by a computer.
There are various methods to classify algorithms. Time complexity (how the running time of an algorithm changes with the size of the input), space complexity (how the required space varies with the size of the input) and optimality (the efficiency relative to other algorithms) are common factors for comparison.
Common types of algorithms include:
- Search algorithms, used to find an item or a group of items in a dataset.
- Sort algorithms, which lay out elements in a certain order.
- Recursive algorithms, which are designed to solve problems by solving smaller versions of the same problems.
- Iterative algorithms, which solve problems via repetitive processes generally involving loops.
- Divide and Conquer algorithms, which break the problem into sub-problems that are similar to the original, solve those problems independently, and combine the solutions.
Algorithms are coded using various programming paradigms, such as procedural programming, object-oriented programming, functional programming or logical programming.
Algorithms are often visualised or planned using pseudocode or flowcharts before being coded into a specific language.
Standard algorithms include linear search for checking every element in a list one by one, binary search which works by recurisvely dividing the list in two parts until the desired element is found, and bubble sort which works by repeatedly swapping adjacent elements that are in the wrong order.
The efficiency of an algorithm is examined by computational complexity theory, which studies the time and space consumed by an algorithm as a function of the size of the input.
Incorrect or inefficient algorithms can result in the waste of computational resources (like CPU time, memory, and communications bandwidth), and can produce incorrect outcomes or fail to solve the intended problem.
Debugging, or the process of identifying and correcting errors or mistakes in an algorithm, is a crucial step in the development process.
Algorithms form the foundation of software and can make a significant difference to the performance and capabilities of a computer programme. Understanding different types and structures of algorithms, as well as how to measure their efficiency, is essential for any effective programmer.