Selection Sort in Swift

The classic

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Difficulty: Beginner | Easy | Normal | Challenging

This article covers the classic sorting algorithm Merge Sort, and it’s implementation in Swift.

• This is seen as a beginner topic (first year Computer Science degree fare) but is certainly not easy.

Terminology

Algorithm: A process or set of rules to be followed

Big O Notation: A mathematical notation to describe the limiting behaviour of a function when an argument tends towards infinity

Selection Sort: An implementation of linear search, where the smallest element is placed sequentially to the front of the list

Selection Sort

The simple theory

A selection sort is about performing a linear search, placing the smallest element sequentially at the front. Since are are performing a linear search for (potentially) every item in the list we are looking at a O(n²) worst case scenario for time complexity.

The tests and function signature