Computer Science Fundamentals

Let’s jump right in at the only place we can: the very begining, diving into the perfectly obvious and terribly argumentative 'rules of logic'.

You're George Boole, a self-taught mathematician and somewhat of a genius. You want to know what God's thinking so you decide to take Aristotle's ideas of logic and go 'above and beyond' to include mathematical proofs.

This is a famous interview question: 'write a routine that adds two positive integers and do it without using mathematic operators'. Turns out you can do this using binary!

Up until now we've been representing binary values as strings so we could see what's going on. It's time now to change that and get into some real binary operations.

We've covered how to add binary numbers together, but how do you subtract them? For that, you need a system for recognizing a number as negative and a few extra rules. Those rules are one's and two's complement.

Now that we know how to use binary to create switches and digitally represent information we need to ask the obvious question: 'is this worthwhile'? Are we improving things and if so, how much?

Claude Shannon showed us how to change the way we encode things in order to increase efficiency and speed up information trasmission. We see how in this video.

There are *always* errors during the transmission of information, digital or otherwise. Whether it's written (typos, illegible writing), spoken (mumbling, environment noise) or digital (flipped bits), we have to account for and fix these problems.

In the previous video we saw how we could correct errors using parity bits. In this video we'll orchestrate those bits using some math along with a divide and conquer algorithm to correct single-bit errors in transmissions of any size.

In this video we play around with cryptography and learn how to encrypt things in a very simple, basic way. We then ramp up our efforts quickliy, creating our own one-time pad and Diffie-Hellman secure key transmitter.

In this video we dive into hashing algorithms, how they're used and what they're good (and not so good) for. We'll also dig into RSA, one of the most important pieces of software ever created.

Functional programming builds on the concepts developed by Church when he created Lambda Calculus. We'll be using Elixir for this one, which is a wonderful language to use when discovering functional programming for the first time

Before their were computers or programming languages, Alonzo Church came up with a set of rules for working with functions, what he termed lambdas. These rules allow you to compute anything that can be computed.

How does a spreadsheet become a highly-tuned set of tables in a relational system? There are rules for this - the rules of normalization - which is an essential skill for any developer working with data

It's a thing you'll need to know if you plan to get through any interview. It's actually quite useful and in this post I'll hopefully make the case that's it's simple as well.

The building block data structures from which so many others are built. Arrays are incredibly simple - but how much do you know about them? Can you build a linked list from scratch?

You can build all kinds of things using the flexibility of a linked list. In this video we'll get to know a few of the more common data structures that you use every day.

The bread and butter of technical interview questions. If you're going for a job at Google, Microsoft, Amazon or Facebook - you can be almost guaranteed to be asked a question that used a binary tree of some kind.

You will likely *never* need to implement a sorting algorithm - but understanding how they work could come in handy at some point. Interviews and workarounds for framework problems come to mind.

You now know all about trees and graphs - but how do you use them? With search and traversal algorithms of course! This is the next part you'll need to know when you're asked a traversal question in an interview. And you will be.

Dynamic programming gives us a way to elegantly create algorithms for various problems and can greatly improve the way you solve problems in your daily work. It can also help you ace an interview.

The use of prime numbers is everywhere in computer science... in fact you're using them right now to connect to this website, read your email and send text messages.

How can you traverse a graph ensuring you take the route with the lowest cost? The Bellman-Ford algorithm will answer this question.

Bellman-Ford works well but it takes too long and your graph can't have cycles. Dijkstra solved this problem with an elegant solution.

Tried and true design patterns for creating objects in an object-oriented language.

As your application grows in size you need to have a plan to handle the increase in complexity. The Gang of Four have some ideas that could work for you.

Mediators, Decorators and Facades - this is the deep end of object-oriented programming and something you'll come face to face with as your application grows.

You've heard the terms before: YAGNI, SOLID, Tell Don't ASK, DRY... what are they and what do they mean?

Testing code has moved beyond the realm of QA and into the realm of design, asking you to think about what you do before you do it. Let's have a look at some strategies.

It's a Unix world. You should have a functional knowledge of how to get around a Unix machine using the command line, as well as how to complete basic tasks using shell scripts and Make files.

I use the static site generator Jekyll to write my blog. I store the site at Github, who then translates and hosts it all for me for free. Jekyll is simple to use and I like it a lot. There's only one problem: it's a bit manual.

I use the static site generator Jekyll to write my blog. I store the site at Github, who then translates and hosts it all for me for free. Jekyll is simple to use and I like it a lot. There's only one problem: it's a bit manual.

Make is a build utility that works with a file called a Makefile and basic shell scripts. It can be used to orchestrate the output of any project that requires a build phase. It's part of Linux and it's easy to use.

No video with this one - just a post with lots of code. Make has been around forever and is often overlooked in favor of tools that recreate precisely what it does, but in crappier ways. Let's see how you can use Make to help your testing process.