Real world implementations of "classical algorithms"

Question

I wonder how many of you have implemented one of computer science's "classical algorithms" like Dijkstra's algorithm or data structures (e.g. binary search trees) in a real world, not academic project?

Is there a benefit to our dayjobs in knowing these algorithms and data structures when there are tons of libraries, frameworks and APIs which give you the same functionality?

Answer 1

Is there a benefit to our dayjobs in knowing these algorithms and data structures when there are tons of libraries, frameworks and APIs which give you the same functionality?

The library doesn't know what your problem domain is and won't be able to chose the correct algorithm to do the job. That is why I think it is important to know about them: then YOU can make the correct choice of algorithms to solve YOUR problem.

Answer 2

Knowing, or being able to understand these algorithms is important, these are the tools of your trade. It does not mean you have to be able to implement A* in an hour from memory. But you should be able to figure out what the advantages of using a red-black tree as opposed to a normal unbalanced tree are so you can decide if you need it or not. You need to be able to judge the fitness of an algorithm for solving your problem.

This might sound too school-masterish but these "classical algorithms" were not invented to give college students exam questions, they were invented to solve problems or improve on current solutions, just like the array, the linked list or the stack are building blocks to write a program so are some of these. Just like in math where you move from addition and subtraction to integration and differentiation, these are advanced techniques that will help you solve problems that are out there.

They might not be directly applicable to your problems or work situation but in the long run knowing of them will help you as a professional software engineer.

To answer your question, I did an implementation of A* recently for a game.