[UNFINISHED] Introduction to Algorithms

Most of the following comes from lecture slides and material by Ran Wei and Andrew Sogokoń from the Lancaster University course “SCC.223 - Algorithms”

Introduction

What is an Algorithm?

• A rule for solving a mathematical problem in a finite number of steps
• A set of instructions or steps designed to provide a method of solving a problem or achieving a result (computing)
• A step-by-step method for solving a problem

- The Chambers Dictionary (TCD)

Algorithms can be thought of as providing blueprints for a program. They outline a solution, which a program then implements.

Example

A simple algorithm returning the absolute of a value:

int abs(int x) {
    if (x < 0) {
        return -x;
    } else {
        return x;
    }
}

Notes

Pseudocode

CLRS 4^th ed. : https://lancaster.primo.exlibrisgroup.com/discovery/fulldisplay?context=L&vid=44LAN_INST:LUL_VU1&search_scope=MyInst_and_CI&tab=Everything&docid=alma9931008930901221

• Algorithms are not language-dependent
• Many are written in psuedocode to more easily convey the idea, instead of syntax
• Unlike in maths, ”=” denotes assignment, and ”==” denotes equality in most programming languages.