Algorithmics
Algorithmic concepts | Super Study Guide
By Afshine Amidi and Shervine Amidi
Algorithm
Given a problem, an algorithm A\mathcal{A}A is a set of well-defined instructions that runs in a finite amount of time and space. It receives an input III and returns an output OOO that satisfies the constraints of the problem.
As an example, a problem can be to check whether a number is even. In order to do that, an algorithm could be to check whether the number is divisible by 2.
An iterative algorithm is an algorithm that runs through a sequence of actions. It is characterized by either a for or a while loop.
Suppose we want to return the sum of all of the elements of a given list. An example of an iterative algorithm would be to sequentially add each element of the list to a variable, and return its final value.
A recursive algorithm uses a function that calls itself. It is composed of the following components:
- Base case: This is the set of inputs for which the outputs are known.
- Recursive formula: The answer of the current step is based on function calls relying on previous steps, eventually using the base case answer.