What is the difference between heuristics and algorithms

As I set about trying to simplify these terms, I realised this might be a helpful glossary to a more general audience:. We hear a lot of talk of algorithms these days slightly less on heuristics, but that will change. Put simply, an algorithm is a mathematical model for completing a task. A heuristic is a mathematical guide to solving a problem. An algorithm is specific and will always work, regardless of the situation.

A heuristic is imprecise, and might not guide you to the right answer, but is the best approximation to hand. At time of writing, computers are essentially mechanical devices with fixed hardware and prescribed software which operates by providing a set of instructions for the hardware to follow in a particular sequence in order to perform a particular task.

While algorithms provide step-by-step procedures that can guarantee solutions, heuristics are faster and provide shortcuts for getting to solutions, though this has the potential to cause errors.

Let me know by commenting or sending me an email! In this video I want to explain the difference between an algorithm and a heuristic and then provide an example that will hopefully help you to see why it is that we tend to use heuristic. First, what is an algorithm? Well an algorithm is a step by step procedure for solving a problem.

The downside of an algorithm is that it tends to be slow because we have to follow each step. If we can follow all the steps, then we will find the solution to the problem. The application of these methods is suitable to solve real world problems or large problems so awkward from the computational point of view that for them there is not even an algorithm capable of finding an approximate solution in polynomial time.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. What is the difference between a heuristic and an algorithm? Ask Question. Asked 11 years, 8 months ago. Active 5 years, 6 months ago. Viewed k times. Improve this question. Joost 4 4 silver badges 16 16 bronze badges. If you look at a heuristic algorithm as a sort of tree structure, I guess you could call it as a special purpose algorithm.

A heuristic is an algorithm that doesn't provably work. Add a comment. Active Oldest Votes. Improve this answer. Another common use for heuristics is in virus detection, where you might not be sure a virus is there, but you can look for specific key attributes of a virus. Heah thats true and for cracking programms — streetparade. Pacerier: yes. It's an algorithm helping to navigate in the solution space of a particular problem. You can also see it as a strategy to modify an algorithm to make it practical a meta-algorithm.

It's still an algorithm, all methods are, and a Heuristic is definitely a method. An algorithm is typically deterministic and proven to yield an optimal result A heuristic has no proof of correctness, often involves random elements, and may not yield optimal results.

Michael Borgwardt Michael Borgwardt k 75 75 gold badges silver badges bronze badges. I would not say that an algorithm is proven to yield an optimal result: it depends on the algorithm with respect to which problem. Yielding an optimal result is not the essential quality of algorithms, it is preciseness i. Buhake Sindi Buhake Sindi 84k 27 27 gold badges silver badges bronze badges. Joost Joost 4 4 silver badges 16 16 bronze badges. I believe your definition of the word algorithm is too restrictive.

Does the use of the word sequence implies non-parallell? Parallell algorithms are fine and even usual nowaday. What about solving a problem using a neural network? Or a constraint propagation tool?

The reader get the feeling NP problems are the worse there is. That's untrue. There are truly hard problems needing truly bad algorithms like exponential ones or worse. NP are special because if we have a solution it is easy and fast to check it, while it is very hard to find it if we don't already have it.

It's easy to check that we have correct instructions to get out of a labyrinth, it's much harder to find the exit. Thus NP are both easy and hard if we could try all possible solutions at the same time non deterministically solving it would be very simple Thanks for the feedback! I've updated the phrasing slightly, and approached it differently. In my view, constraint propagation is a technique to approach something, but is not yet an algorithm that describes how to step-wise come to the solution described in constraint propagation.

You are ofcourse correct about the classes of expspace and 'worse', I've added a note on that too. Of course you are right I should have written NP-Complete.

My bad. It's way better than what one of my colleagues names it: NP-ness which sounds just awful and kinda gross Lazarus Lazarus