Interview Exercises: The TDD Way


I'll be honest with you, I suck at algorithms and data structures. Trying to figure the proper approach is a difficult and brain-frying endeavor. And don't get me started on the recursion, which makes everything 10x more challenging to reason about.

GitHub for PHP Interview Exercises

Luckily things get easier with experience, repetition and simple know-how. Old challenges that seemed insurmountable become easier to reason about. That's why I love to return and rehearse some basic algorithms and data structures from time to time. It just makes you feel better when you finally understand how a linked list works, or a tree traversal is accomplished.

Test-driven development

Wikipedia for TDD

This time I wanted to try a TDD approach (more or less.) By writing a test first, and the implementation with possible refactor it is easier to solve a problem. Instead of staring into an empty code editor you start writing and thinking about the problem.

To write a proper test you need to:

  • Understand the problem (What is my goal)
  • Explore test cases (Find proper input and output)

And already half of the problem is solved. Now what rests is to create a solution.

What we can do now is:

  • Break the problem down into smaller chunks & solve it
  • Simplify once all the test are green
  • Look & Refactor for performance (Remember that premature optimization is bad)

Problem-solving is an important skill to hone for a developer. By practicing on smaller chunks of code it is easier to gauge one's level and simply stay motivated.

Happy coding!