Introduction to Algorithms and Data Structures in Swift 5

In this section we are going to talk about computational complexity. The Big-O notation is a mathematical model used in computer science to describe the efficiency of algorithms as a function of their input size. 

The best way to understand the Big-O thoroughly is via code examples. Therefore, we are going to illustrate each concept using live Swift coding.

This lecture is about the Linear Time complexity. As usual, we'll not only talk about the theory, but we are going to also illustrate O(n) via Swift code examples.

The topic of this lecture is the Quadratic Time complexity. We are going to delve into the world of nested loops and we'll discuss why they should be avoided if possible.

Do your best to avoid polynomial - and worse - time complexity. This lecture explains what to do if you encounter O(n^k).

Let's take a closer look at the logarithmic time complexity. Logarithmic time represents an extremely efficient algorithm, used by the binary search technique for example.


Understanding the Big-O notation paves the road to working with algorithms. This lecture is a brief summary of what we've learned during this module.

Big O Quizzes

Xcode playground projects for the Big-O section.

An overview of what we're going to cover in the Recursion section.

In this video, I'm going to walk you through a demo to show you how recursion works. We're going to also solve an interesting problem.

Recursion is great, but it doesn’t come without pitfalls. The biggest problem is infinite recursion. I’m going to illustrate it using an Xcode playground project.

There are two basic rules we need to follow to avoid infinite recursion. Let's take a closer look at them.

Recursion Quizzes

Recursion demos.

In this section, we are going to take a closer look at the importance and the benefits of algorithms and algorithmic thinking.

In this lecture, we are going to implement a function which calculates the sum of the first N natural numbers. We’ll start with a naive implementation. 
Then, we are going to implement a more efficient way to solve this problem using a formula that is more than 2000 years old.

Our task is to implement a function that, given an array and a target value, returns zero-based indices of any two distinct elements whose sum is equal to the target sum.

In this lecture, we are going to build a function to find the equilibrium indices of an array. The equilibrium index of an array is an index such that the sum of elements at lower indices is equal to the sum of elements at higher indices.

In this section, we’ve seen some practical examples of solving problems using two different approaches. Let's recap the biggest take-aways.

The Power of Algorithms - Xcode playground projects.

This is what we're going to talk about in this section.

In this video, we'll try to solve a problem using a naive approach. We'll see where this leads and why generics are the way to go.

Generic structures provide an elegant solution to the problem presented in the previous lecture. Here's how.

Generic functions can work with any type. In this lecture, I'll show you how to avoid code repetition. We'll also talk about generic functions and type constraints.

Let's test your knowledge about Swift Generics!

Xcode playground projects for the Generics section.

We’ve seen that the array stores elements in a given order. We can even have duplicates in an array.
What if we need a collection that guarantees the uniqueness of its elements? The Set is the answer!

Now that we know how to create a Set, let’s talk about accessing and modifying its contents.

The Set exposes useful methods that let us perform fundamental set operations.

There will be cases when you need to adopt the Hashable protocol.
For example, if you want to create a Set with your custom type, or use it as a key in a Dictionary, you can't avoid conforming to Hashable.

The Dictionary, also known as hash-map, stores key-value pairs. In this lecture, we're going to talk about topics like dictionary creation, heterogeneous dictionaries, the AnyHashable protocol and much more.

The Dictionary provides various methods to access and modify its contents. This video takes a closer look at these methods.

Test your knowledge about the Array, the Set and the Dictionary

Xcode playground projects for the "Built-In Swift Collection Types" section.

In this section we are going to talk about basic sorting algorithms.
Understanding the inner workings and knowing how to implement the basic sorting algorithms gives you a strong foundation to building other, more sophisticated algorithms.

We'll start the study of basic sorting algorithms with the selection sort algorithm. We are going to implement it in Swift. We’ll also visualize how selection sort works and we’ll analyze the time complexity of this algorithm.
Finally,we are going back up the theory with performance tests.

Let's quickly recap the pros and cons of the selection sort algorithm.

Insertion sort is a basic sorting algorithm, which works by analyzing each element and inserting it into its proper place, while larger elements move one position to the right. 

Insertion sort has quadratic time complexity. However, the performance of the insertion sort is largely affected by the initial order of the elements in the sequence.

In the previous lecture, we took a closer look at the insertion sort algorithm. Did you know that even Apple uses it in their sort() implementation? Check out why!

The topic of this lecture is Bubble Sort. This algorithm works by repeatedly evaluating adjacent items and swapping their position if they are in the wrong order. While it's easy to grasp and implement, you don't want to use it in production code. Let's see why!

A brief summary of the bubble sort algorithm.

Test your knowledge on basic sorting algorithms.

Xcode playground projects for the Basic Sorting section.

A brief overview of what to expect in this section.

The merge sort is a fast divide-an-conquer algorithm. Check out this lecture to see what that means.

Merge sort in a nutshell.

In this lecture, we'll analyze the famous quicksort - the king of the compare-based sorting algorithms.

Let's recap what we've learned about the popular - and fast - quicksort algorithm.

Quizzes for the Advanced Sorting Algorithms section.

Xcode playground projects for the Advanced Sorting section.

Apple introduced property wrappers in Swift 5.1 along with other useful features. Property wrappers are an elegant alternative to redundant property setters and getters. In this article, I provide a quick overview of property wrappers using hands-on Swift code examples.

Let me give you some useful online resources which will help you in sharpening your coding and problem solving skills.

Here's the companion eBook as a special gift to you (124 pages print length, sells for $28.80 on Amazon).

I share some links that will get you discounts on my other courses.