Interview questions for self-preparation

Question

Java

Greetings,

In a couple of days I'm going to a personal interview at Zynga (in Moscow), so I decided to get ready :)
My specialization is development for mobile platforms, lately more android.
At a telephone interview, they offered to choose from the languages ​​\u200b\u200bc ++, java, phyton - I will probably choose java sooner if they ask (although I will declare that I also know c ++).

What will be asked is not clear. Rather general questions without specialization.

Ask questions? What do you think they can ask there?

Answer 1

1) Estimating complexity of insertion/search in different structures
2) Deadlock
3) Weak, Soft-references
4) Write some kind of sorting
5) What does the final keyword do?
6) String.intern()
7) equals() and hashCode() contract
8) count set bits in number

Answer 2

Be less nervous and answer honestly - what you did, what you didn’t give, what you worked with, what you didn’t. Don't ask for a lot of money. In general, your knowledge is only 50% of success. Much more important is how adequate a person you are, how many projects you have completed, whether you are engaged in self-education, whether you like your work, and so on. It seems to me - because an intelligent and interested programmer can be taught anything in a few months, but it is almost impossible to bring up responsibility or diligence in him.

Answer 3

So, I'll start myself. Everyone will be useful.
And so, taken from glassdoor
1. cycles in linked list, that is, the search for cycles in a linked list
2. blocked queue - implement (at the same time learn how to pronounce queue :)
3. desk class (sheffle desk) - like a class for a card deck
4. convert string to integer
The first is nonsense, the second as a whole, too, although you need to think about how elegantly you can shuffle the deck in Java, the latter is not clear what the trick could be.

Answer 4

I always ask: polyformism, encapsulation, interfaces.

Answer 5

The report is below, it is also available at the link - www.rsdn.ru/forum/job/4316931.1.aspx
I will add that it was clearly superfluous to remember the implementation of the blocked queue, and in general to remember everything related to concurrency. Which is logical though. Even if you have 15 minutes for a task, it is unlikely that you will be able to write it on a piece of paper and discuss it further. Well, various red-black trees are also perhaps an overhead - although in general there may probably be a task where they will be optimal.
There were no tasks like “exposed bits in a number” either - again, in my opinion, it is logical, because it is too specific. Although, again, there may probably be a more general task where this can be applied.
But the tasks have more than one solution :)
I will also add that there were no questions related to the specifics of a particular programming language.
The interview took place at the Marriott Hotel.
There were 6 applicants and 5 interviewers plus Mat himself.
For the first 30 minutes, Mat talked about Zing and gave advice on interviews, there were three main tips
- listen carefully to what they say so as not to start solving the wrong task (it turned out to be relevant for me - because I did not fully understand the first task, and spent 5 minutes in empty
- start with simple solutions
- communicate with interviewers, and not silently write decisions on paper (again, it turned out to be relevant for me - if I normally communicated with the first four interviewers, then with the fifth - after the fact I ran it from memory, I realized that 80% looked at the paper and told the solution to the paper, not to the person)
Of interest - he said that they have branches in 5 cities at the moment
Los Angeles
San Francisco
Austin, Texas
Dallas, Texas
Baltimore
Some have teams that they recently bought, for example the team that does Civilization
has now grown to 2000 people, plans to recruit 150-300 every quarter (??? could not understand correctly)
Also said that they had already been here for three days and had already made an offer to some of them.
He said that he would talk to each of them from 3 to 5 interviewers, and they say the number does not mean anything.
Each applicant had his own room - an ordinary room with a toilet and everything, from which the bed was removed and a large table with a couple of chairs was placed there.
The system is like this - you are in this room, the interviewer comes to you for 35-40 minutes, then you have a 15-minute break, you are alone in the room (walk around the table, drink water, lie down in an armchair, look at albums - then the next one
There was water on the table, and also 5 books - photo albums with descriptions for each city listed above
Questions can be divided into four types
1 - work in general - why are you doing this, how long, what interesting projects, what challenge, what do you want, why do you want, about the industry in general
2 - logical tasks - I either knew all the tasks before, or just heard about them
3 - tasks for writing code - i.e. There is a problem that needs to be solved. Half of them actually need to say what data structure is better to use and do some operations on it, the second is just to write an algorithm.
4 - tasks of a general IT nature - here is such a problem how to solve or here is such a process - tell us more about it, or here is such a system - how to organize it
It should be noted on point 3 - obviously I wrote God forbid lines 5 of code, everything else I actually rather, he drew a block diagram and told how it would work.
The first three interviewers asked any 3 points out of four, with the fourth we spoke only about 1 point, with the fifth only about the 3rd.
Tip - take some type of chocolate chtoli yourself. For by the fifth interview it was already frankly hard and I would not mind refreshing myself.
For the last couple of minutes, all the interviewers offered to ask them questions.
We started at about fifteen minutes to two, I finished at half past six.
The overall result - I rate communication with the first four at 9 out of 10 and, well, maybe 8. I didn’t solve one logical problem - or rather I found a solution that is close to optimal - but not optimal the second percent by 80 did.
After the fifth we talked with Mat for a bit.
He said that they are here for another three days (another 35 or 45 applicants), on Monday they are already in the USA and actually from Monday to Wednesday he will give an answer.
And he said so interestingly - that if not, then rather on Monday, if yes, then rather on Wednesday.
Well, let's not wait for a quick answer.
When I left, none of the other applicants were there.
Interesting enough, how many interviewers did anyone have, and did anyone get an answer on the same day??
English - three of them are very understandable and slow, one speaks fast enough - but we mostly talked about algorithms (well, or I said) - it was not difficult, one did not have a very clear pronunciation - but it’s true that he was the fifth, so it’s possible it's just my tiredness.
I liked the interview itself very much - everything was clear, logical and comfortable. Although it is still difficult for five interviewers to get used to it. Well, maybe someone passes in 3 conversations
From the remarks to yourself
- even if you know the answer well - then do not part and do not rush to answer, firstly, English suffers, secondly, it is better to answer a question that you know well than later to answer a question that you may not know
- if from you write a block diagram and explain its work, and the interviewer has not moved to one half of the table with you before - then it’s probably better to turn the sheet a little towards him, and yet after each block look at it, and not explain the sheet
- if you are talking about the decision , and after each offer they start saying to you - ok, eu, ok, then you can probably already interrupt
PS I talked with Mat about the relocation package - paying for tickets for the family, 2 months renting an apartment next to work, plus $ 4,000 for expenses.
PPS I asked one interviewer what he thinks about Erlang - the general answer was this - erlang is good, but firstly he thinks that there simply aren’t the number of programmers they need on the market who already know erlang, and plus he is not sure that retraining of existing ones will go well - because changing the programming paradigm will be difficult. Therefore, it can be local and in bottlenecks, but not globally.

Answer 6

So did you end up taking it or not?

Answer 7

Yeah thanks. 5) for a class, final means that it is not possible to override its any method, for a method it means that it is impossible to override
it, final variables can only be assigned once
string in string poll and returns the same. Is that all or is there more to say?
8) I would not write, I would tell in words that you can make a plate for each byte, and go through it byte by byte. Well also specified that we save memory or speed. I would say that it is possible without a sign, but there will be scary masks that I don’t think it makes sense to remember, well, the classic method would mention which result += x & 1; x >>>= 1; if it would make sense

Answer 8

Implement copy-on-write ArrayList (four methods in total - void add(int indx, int item), int get(int indx), void remove(int indx), int size()).

Answer 9

What did you end up asking?

Answer 10

And thank you all.

Answer 11

Hello, I filmed the roles here and I'm going to shoot more on the topic. Maybe someone will be useful.
https://www.youtube.com/watch?v=IyPaSUFrhaM