Preface

I am a bottom-level 211 undergraduate. I have just graduated with no scientific research experience, but have some project experience.
Worked for a period of internship in a leading company in the domestic surveillance industry.
Thinking of investing in a byte, you can accumulate a trial experience and prepare for the golden, nine, and silver moves. After
I
submitted my resume, after a period of time , HR called me to make an appointment and explained that I voted for Beijing office.
The following is the whole process of an interview, share it with friends who are interested.

one side

The interviewer is very kind. At the beginning of a self-introduction, I immediately started to ask the item, such as:
(Answered SpringBoot, Redis, Mysql, etc., which are often used by myself. There is basically
no Java background on the byte side . , So I feel that the tester will not ask Spring, Java, etc., but it is for the database and intermediate

1. What are the commonly used web components?

Piece ⽐᫾interested)

2.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 test officer, because Kafka is really not prepared enough, but the state is stable)

3. Mysql index, B+ tree (must take the test, students!!!)

There are also some details in the items, these are different, so I won't put them up.
One reminder is to introduce some dazzling places in the project,
such as what powerful data structure is used, what are the characteristics of the architecture, the amount of concurrency is large, and how to hold the amount of concurrency!
After that is the algorithm problem , I have done two in total

1. Determine the balance tree

This question is not difficult in general, but the examiner has interspersed the knowledge of garbage collection in the middle, which is very uncomfortable.The
specific thing is to judge when the object will be recycled, and what is the reachability analysis. At that time, it is
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 only the
stack frame size changes, there should be There are two peaks, and there will be jitter in the middle)

2. Variations of the sub-point search method

Given a target and an ascending array, find the next number that is smaller than the number of the array. This question is not difficult,
depending on the familiarity of the score search method. Of course, there is an optimization point here. , You can check my blog for inspiration
.

The test officer asked me to wait for a while, about 10 minutes, let me continue after a short break

Two sides

First of all, let me introduce myself, of course, the same routine, the same crispness,
and then asked me some questions about Redis ,
like the implementation of zset (jump table, this high frequency), the key expires Strategies, persistence, etc.,
these can be found in most Redis introductions, so I won't go into details!

There are also some data structure issues:

1. Rather than asking what a hash table is, I gave the
tester a detailed explanation of how java.util.HashMap is implemented (of course, there are red trees interspersed with red trees. Look at the red trees. What are the characteristics?
2. Including why the chain address method is used to avoid conflicts and what are the detection methods?
3. Comparison of the advantages and disadvantages of chain address method and detection method

Later, I also discussed a long-term project with me, so I said that the project of the home must be done well, and there must be places with bright spots. Here, I have discussed
many optimization projects with the test officer . What's wrong, where else can you add new features, etc.?
I also didn’t elaborate on it. During the
discussion, I cracked and knocked a lot. It should be a kind of evaluation of the person’s face.

The latter part is the traditional art tearing algorithm of bytes. Three channels are made and one
channel is 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}.
1. The first question is what is the relationship between their numbers (1 3 7 15...2
n times -1, solved by bitwise arithmetic).
2. The second problem is that given the number of arrays 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 I do it. If there is any, everyone can share the next
3, the third is the next permutation: https://leetcode-cn.com/ The question type of problems/next-permutation, but
some modifications have been made, the array size is 10000<n<100000, and the brute force method cannot be used, and the number will be repeated between 1-9

HR face

There are some topics that are biased towards career planning, internship time, project experience, and internship experience.

to sum up

The foundation is important!
I have asked about the principles of Redis, Mysql, JVM, etc. that 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 a test, but also in the future. The knowledge base of the work).
Of course there are ready Your Own underexposed places subject:
⽐ middleware such as Kafka, not only Using the principle is absolutely not perform while the basics and not just back, ⾯ interviewer will melt.
Fit the item destination time ⾥ Cross-examination

Secondly, don’t panic if you don’t, because the examiner is testing your technical depth, and may be directed to a certain question. You won’t be wrong when asked, so it’s normal for you to have questions that you won’t.
Keep your attitude under control. Regardless of whether you are doing a question or answering a question, remember that you are not taking an exam, but communicating. It is very important to interact and communicate with the examiner.
You say something The omissions, if you give feedback to the tester in time, you can still remedy them.

The most important point of the byte test is that the algorithm must be firm, and there will be a tearing algorithm in every round!
No need to think about it, LeetCode+jian points to the Offer niche.
State is very important. You may not know how to solve the algorithm problems. You need to be prepared for a certain amount of reason. If you encounter a problem, you can calmly analyze it first.
It is also important to write bug free code.
Finally, I wish you your favorite offer on the occasion of the golden nine and silver tenth, and
I will give it to you! The above is an experience of my own interview in 2020.