Note: The byte offer of this interview in March during the epidemic

Basic conditions

I am a bottom 211 undergraduate and have no scientific research experience, but I have some project experience. I did a period of internship in a leading company in the domestic surveillance industry. Thinking about voting for bytes, I can accumulate interview experience and prepare for spring recruitment. After I submitted my resume, after a period of time, HR would call me to make an appointment and conduct a remote interview after the year.

To explain, I voted for the Beijing office.

one side

The interviewer is very kind. Due to the epidemic, everyone conducts remote interviews at home.

I didn't introduce myself at the beginning, I just started to ask the project, and asked for example

What are the commonly used web components (answered SpringBoot, Redis, Mysql, etc. that I often use, but there is basically no Java backend here, so I feel that the interviewer is not likely to ask Spring, Java, but it is for the database (More interested in middleware)
Kafka-related, how to ensure that there will be no repeated consumption, Kafka consumer group structure, etc. (this is only based on feelings and the interviewer said, because Kafka itself is not fully prepared, but the mentality is stable)
Mysql index, B + tree (compulsory wailing students)

There are also some details in the project. These vary from person to person, so I won't put it up. The tip is to introduce some bright points in the project, such as what awesome data structure is used, and what are the characteristics of the architecture. How to hold the concurrency

Next is the algorithm question, I have done two in total

Judging the balanced binary tree (this question is not difficult in general, but the interviewer interspersed the knowledge of garbage collection in the middle, which is uncomfortable. The specific thing is that everyone has to judge when the object will be recycled, and accessibility analysis When is it unreachable for this object, and how the memory changes in the recursive function, this is for us to model the execution process of this function. If we only look at the stack frame size change, there should be two Peak, there will be jitter in the middle)
A variant of the binary search method, given a target and an ascending array, find the next number larger than the array. This question is not difficult. It depends on everyone's familiarity with the binary search method. Of course, there is an optimization here. For the point, you can look at my blog for inspiration

After I was finished, the interviewer asked me to wait for a while and there will be two sides, about 10 minutes or so, and I will continue after a short rest.

Two sides

Two sides and one up is to let me introduce myself first, of course, the same routine, the same crispy

Then I asked me some questions about Redis, such as the implementation of zset (jump table, this high frequency) , key expiration strategy, persistence, etc., which can be found in most Redis introductions, so I won't go into details.

There are also some data structure questions, such as asking what the hash table is, and telling the interviewer how java.util.HashMap is implemented (of course, there are red-black trees interspersed with it, look at the red-black trees more What are the characteristics or the like), including why the chain address method is used to avoid conflicts, what are the detection methods, and the comparison of the advantages and disadvantages of the chain address method and the detection method

Later, I discussed a long-term project with me, so everyone's project must be done well, and there must be bright spots. Here I have discussed with the interviewer many areas of project optimization, what are the shortcomings, and what can be new? Increased functions, etc., the same is not going into detail

I cracked a lot while discussing, it should be a kind of personal interview evaluation

Behind is the byte's traditional art hand tearing algorithm, a total of three

One and two paths are connected together. Given a rule S_0 = {1} S_1={1,2,1} S_2 = {1,2,1,3,1,2,1} S_n = {S_n-1 , n + 1, S_n-1). The first question is what is the relationship between their numbers (1 3 7 15... 2 is n-th power -1, solved by bit operation). The second question is to Set the number of arrays with subscript n and index k, let us find the number pointed to by S_n(k), if S_2(2) = 1, I don't have any good ideas when doing it, if there is any, you can share a bit
The third one is the next permutation: https://leetcode-cn.com/problems/next-permutation question type, but some modifications have been made, the array size is 10000<n<100000, violence method cannot be used, and the number is There will be repetitions between 1-9

hr noodles

Some topics are more professional planning, internship time, project experience, and internship experience.

to sum up

The foundation is very important! I have asked about the principles of Redis, Mysql, JVM, etc. I prepared this time. (The network is not asked, but it is also necessary to prepare well. For the background, network knowledge is not only an interview, but also in the future. Knowledge base of work). Of course, I also have insufficient preparations. For example, middleware such as Kafka, it is absolutely impossible to only use the principle. And these basic knowledge can not only rely on the back, the interviewer will also integrate it into the project. ask

Don’t panic if you don’t know, because the interviewer is testing your technical depth, and it is possible to focus on a certain question, and ask until you can’t, so it is normal for you to have problems that you can’t, and your mentality is under control. Just fine.

Whether you are doing a question or answering a question, keep in mind that you are not taking an exam, but communicating. It is important to interact and communicate with the interviewer. Some omissions you mentioned, if you give feedback to the interviewer in time, Can still be remedied

The most important bit of a byte interview is that the algorithm must be firm. Every round will have a shredded algorithm. Don't think about it. LeetCode+ Sword Finger Offer is right. The mentality is very important. Yes, you must have a certain degree of psychological preparation. You can calmly analyze the wave when you encounter problems. And it is also very important to write bug free code. The algorithms in front of me have to be run because they are interviewed on Niuke.com.

Finally, I wish everyone a good offer in the spring recruitment, Aoli will give it!

The editor is here to share a wave of interview books and interview documents compiled by myself for everyone to review!

Including (JVM, multithreading, high concurrency, Spring, Nginx, Dubbo, Redis, microservices, Kafka, MySQL, etc.)

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Writing: Zuo Chengyun

This is a programmer interview book! The book summarizes the optimal solution for the category conversion of IT names attempting to interview, and provides related code implementations. In view of the lack of authoritative summary of current programmer interviews, this book selects "nearly 200 classic code interview questions that have actually appeared, to help programmers be foolproof in their interview preparations.

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