Answer 1

I have no professional experience in evaluating algorithms, but based on common sense:

A good algorithm :

• should be efficient :
- solves problems in the least steps possible.
- uses minimal resource to achieve the solution.

• should be easily understood :
- reflects real-life problem-solving steps.
- can be maintained at minimal cost.

• should be flexible :
- handles all kinds of exceptions and errors.
- is self-sustainable.
- can be applied in a wide variety of similar problems.

• should have balance (!) :
- The shortest and most efficient algorithm may not be the most readable/maintainable. Suitable algorithms should be chosen after evaluating specific conditions in real life.

• should actually solve your problem.

Answer 2

well Ace u know more than me but my views are:
The characteristics of a good algorithm are:
1.Precision – the steps are precisely stated(defined).

2.Uniqueness – results of each step are uniquely defined and only depend on the input and the result of the preceding steps.

3.Finiteness – the algorithm stops after a finite number of instructions are executed.

4.Input – the algorithm receives input.

5.Output – the algorithm produces output.

6.Generality – the algorithm applies to a set of inputs.

Answer 3

How fast the black box returns something? (Runtime)

Answer 4

{Walks into black box store}

Oh look, the algorithm in this one generates waste heat. But I bet this would keep someone's toes warm on a cold winter night ~

{Walks into a forest}
Trees!*

* Box-making materials.

Answer 5

Simplicity and the one that uses less time.
I think majorly that time is the big thing here

Answer 6

adding a last point :

should be as crossplatformed as possible or
constraint independent as possible

Answer 7

Simplicity :)

Answer 8

@Ace: I would say by storing the string in an array and checking against a single character first using a loop condition and set up some sort of flag to tell me if any are missing from that set or not (1-9). next, id repeat the process and check against a double character (10-99) to see if anything is missing. if so, I will find my value. if not, repeat and check against a triple character (100-250) to see what is missing. using this method, the algorithm is optimized so that I only check each group once. i would probably code this in c/c++ if necessary

I could on the other hand sort the numbers first before attempting to find the missing number, but that would increase my overal run-time complexity

Answer 9

I good algorithm is one that is free of mistakes or errors. This way your code always satisfies the right answer and never fail. That's why I think keeping your code safe is important. There are programs that helps doing that you can use, such as checkmarx which I've heard of.
Good luck.

Answer 10

A good algorithm should address the problem at hand without propagating another issue in a simplistic way. Space and Run-time complexity should also be considered.

@Ace: Got an interview at Google in two days. I've been doing some independent study on Data Structures and Algorithms so far, but would you recommended any last minute prep that I should consider focusing on?

Answer 11

@Ace . Ok, well I just ordered a book from Amazon a few days ago: Programming Interviews Exposed and it seems to really lay out everything regarding Structures, Algorithms, and some System Design topics, I think.

Im well aware of the NDA, and I wouldn't want to neither compromise myself or anyone else. I think I'm more nervous than anything else. If I can manage to pick up multiple programming languages within a short period of time and also be able to teach myself about data structures and algorithms, I should be fine. I really just want to do well and make it to the next round

Just as a simple test, could you provide me an abstract practice problem that I could potentially be tasked to solve? (One that is NOT related to Google.)

Answer 12

Algorithms can make systems smarter, but without adding a little common sense into the equation they can still produce some pretty bizarre results.

The characteristics of a good algorithm are:
Precision – the steps are precisely stated(defined).
Uniqueness – results of each step are uniquely defined and only depend on the input and the result of the preceding steps.
Finiteness – the algorithm stops after a finite number of instructions are executed.
Input – the algorithm receives input.
Output – the algorithm produces output.
Generality – the algorithm applies to a set of inputs.

Regards,
Christian

Answer 13

@Ace: Could you give me another more challenging algorithmic problem? Something that I would have to put even more considerable thought into?