Question

In many languages, for me specifically, Java and C++, there is an massive standard library. Many classic problems in computer science, search, sorting, hashing etc etc… are implemented in this library. My question is, are there any benefits of say implementing one’s own algorithm versus simply using the library’s version? Are there any particular instances were this would be true?

I only ask because in school a huge deal of time is spent on say sorting, however in my actual code I have found no reason to utilize this knowledge when people have already implemented and optimized a sorting algorithm in both Java and C++.

EDIT: I discussed this at length with a professor I know and I posted his response, can anyone think of more to add to it?

Answer 1

After discussing this at length with professor of Computer Science, here were his opinions:

Reasons to Use Libraries

1. You are writing code with a deadline.

• There is no sense in hampering your ability to complete a project in a quick and timely manner. That’s why libraries are written after all, to save time and avoid “reinventing the wheel”

2. If you want to optimize your code fully.

• Chances are the team of incredibly talented people who wrote the algorithm in Java or C++’s or whoever’s library did a far better job at optimizing their algorithm for that language in however long it took them than you can possibly do in an hour or two. Or four.

3. You’ve already done previously solved this problem.

• If you have already solved this problem and have a good complete understanding of how it is designed you don’t need to labor over a complex solution as you don’t stand to gain much benefit.

That being said, there are still many reasons to make your own solution.

Reasons to Do It Yourself

1. A fundamental understanding of problem solving techniques and algorithms are completely necessary once you reach a problem that is better optimized by a non-library solution.

• If you have a highly specified problem, such things often come up when working with networking or gaming or such. It becomes invaluable to be able to spot situations in which a specific algorithm will outperform the libraries version.

2. Having a very good understanding of algorithms and their design and use makes you much more valuable in the work place.

• Any halfway decent programmer can write a function to compare two objects and then toss them into a library function, however the one that is able to spot a situation and ultimately improve the programs functionality and speed is going to be looked upon well by management.

3. Having the concept of how to do something is often just as, if not more so, valuable than being able to do it.

• With an outstanding knowledge of Java’s libraries and how to use them, chances are you can field any problem in java with reasonable success. However when you get hired to work in erlang you’re going to have some rough times ahead. Where if you had known how and not merely what Java’s libraries did, you could move those ideas to any language.

4. We as programmers are never truly satisfied with merely having something “work”.

• Chances are that you have an itch to understand why things work. It was this curiosity that probably drove you to this area of study. Don’t deny this curiosity! Encourage it and learn to your hearts content.

5. Finally, there is a huge feeling of success and accomplishment that comes with creating your own personal way of sorting or hashing etc.

• Just imagine how cool your friends will see you when you proclaim that you can find the shortest path between 2 vertices in n log(n) time! On a serious note, it is very rewarding to know that you are completely capable of understanding and choosing an optimum solution based on knowledge. Not what some library gives you.