How do I explain what a “naive implementation” is? [closed]

Answer 1

Determining if a number is prime or not (primality test) is an excellent example.

The naive method just check if n mod x where x = 2..square root(n) is zero for at least one x. This method can get really slow for very large prime numbers and it is not feasible to use in cryptography.

On the other hand there are a couple of probability or fast deterministic tests. These are too complicated to explain here but you might want to check the relevant Wikipedia article on the subject for more information: http://en.wikipedia.org/wiki/Primality_test

Answer 2

Doing it the most straightforward, least tricky way available. One example is selection sort.

In this case naive does not mean bad or unusable. It just means not particularly good.

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Taking Jon Skeet's advice to heart you can describe selection sort as:

1. Find the highest value in the list and put it first
2. Find the next highest value and add it to the list
3. Repeat step 2 until you run out of list

It is easy to do and easy to understand, but not necessarily the best.

Answer 3

another naive implementation would be the use of recursion in computing for an integer's factorial in an imperative language. a more efficient solution in that case is to just use a loop.

Answer 4

StackOverflow's Jeff Atwood had a great example of a naive algorithm related to shuffling an array.

Answer 5

"Naive implementation" is almost always synonymous with "brute-force implementation". Naive implementations are often intuitive and the first to come to mind, but are also often O(n^2) or worse, thus taking too long too be practical for large inputs.

Programming competitions are full of problems where the naive implementation will fail to run in an acceptable amount of time, and the heart of the problem is coming up with an improved algorithm that is generally much less obvious but runs much more quickly.

Answer 6

Let's say that someone figures out how to extract a single field from a database and then proceeds to write a web page in PHP or any language that makes a separate query on the database for each field on the page. It works, but will be incredibly slow, inefficient, and difficult to maintain.