Project: NeetCode Blind 75 Solutions

Project background

LeetCode is rather infamous in the programming world. It’s a site where you can solve and practice programming algorithms. There are a lot of problems of varying difficulty. This idea is to try solve the problem in as effecient a way as possible. The skills you learn from these challenges serve you in good stead for later, as many of the principles you learn have broad application.

This project / repo contains my solution to the NeetCode Blind75, which is a small, curate list of LeetCode problems that are commonly asked in interviews.

Why this project

I started the Blind75 for a couple different reasons:

1. I was preparing for interviews, and I wanted to be sharp and have some practice with the kinds of problems that are commonly asked.
2. I am a self-taught developer, and I figured this would be a good way to maybe fill in some gaps when it comes to data structures and algorithms (DSA).
3. They’re kinda fun actually.

I figured if I’m going to be doing these problems, I’d might as well make it visible. So instead of just keeping the code on Neet- / LeetCode, I would put it in my own repository, where I own it and can also have multiple solutions to the same problem.

Languages

You can solve the problems in many different languages on the Neet- / LeetCode website. I opted for Python initially, as it’s very direct and you are able to really focus on the algorithmic thinking rather than issues of memory management etc.

I took a break from this project for a while (I got finished the Linked List group, ~30% of the problems), and when I came back to it after a few months I decided to begin again with Java. Once I’ve caught up to where I am with Python, I’ll switch back to Python and continue.

Other technical aspects

Aside from the solutions themselves, there are some other interesting technical aspects to this project.

Consolidated test data

Once I added Java as a second language for the solutions, I decided to extract the tests cases into a separate data file. I decided to go with JSON, being so ubiquitous and ergonomic. Now every language will use the same test cases automatically.

Reusable Java test class

For the Java solutions, I created a reusable test class that automatically gets picked up by JUnit and runs the parameterized tests. All you have to do to create a new test is extend the base class and override the required methods. New tests can be added in seconds, and the test data is automatically pulled from the JSON file.

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This is a living repo, and I am adding solutions occassionally. I’m also blogging about some of the problems.