Beating the intelligence agency (well, at their Christmas puzzle)
Every year, the Dutch equivalent to the CIA publishes a Christmas puzzle as a fun challenge for the general public. Having some programming skills can definitely help to solve these tough problems, but only when combined with clever observations and logical reasoning.
In this ‘case study’, we will look at one of these problems and my journey to solve it using PHP. We will look at modelling the problem, implementing a blunt brute force approach (spoiler: it’s nowhere near fast enough), and iteratively using our own analytical skills to refine the solver algorithm, ultimately arriving at a strategy that solves the puzzle in no time.
While solving such puzzles will probably not earn you a living (if you do, let me know 😉), they can teach us some valuable skills that are useful in our day jobs. We will learn about creating robust and expressive domain models, natural language detection, algorithms and data structures to improve our performance. But most of all we will sharpen our problem solving skills, turning our failed attempts into insights for better approaches.