ByteDance Android interview, summary of knowledge points + analysis of interview questions

Preface

In the last year 10 I joined a foreign company in June , It coincides with the large-scale recruitment of the company in recent weeks Android Development , Fortunately, I have participated in more than ten interviews , So I have a feeling . There are also some ideas from the aspect of interviewers , I hope to share with you .

Originally as an interviewer for me is a relatively new thing , But after a few interviews , I feel that I have a more three-dimensional feeling about the interview . I hope the following sharing can bring you a little help . Here is the text ：

First of all, let's talk about my feelings , There are several key points in the whole interview process , If you master the key points well, you have a good chance to pass the interview

Ali

Ali's intern recruitment, I participated in the internal batch and the official batch, a total of two .

Ali's internal batch and official batch are completely staggered , That is to say, the official batch will not be started until all internal push is finished . It should be noted that , Ali's main departments （ The group 、 rookie 、 Ants, etc ） Almost all of the recruitment is in the push batch , Most of the official batches are non major departments （ Gao de 、 Youku tudou 、 Small shrimp 、 Nails, etc ） Recruitment .

There is no unified written test for Ali's extrapolation , After the success of internal push , I'll be informed of the quality assessment and programming test soon . However, these two assessments are not of great significance , It'll be quick to do it or not （ A day or two ） I started the interview . All of the interviews are phone interviews . I got a phone call the next day after the push , The Department is a rookie / wireless （ I can't remember clearly. ）.

The extrapolation side is about 40 minute , The main question is the basis of computer , Such as HTTP、TCP、 Concurrent 、 Binary tree traversal 、 String matching algorithm, etc , Let me also briefly introduce two projects I have done . Because one of my projects did APP There are the distribution and collection of questionnaires , So I asked how to prevent someone from brushing the questionnaire ; I replied that it was possible to limit IP、 Record the unique number of the device 、 Monitoring, questionnaire, etc , But there are some loopholes . Finally I asked him Android Will there be many compatibility problems in the development process , The interviewer replied that he would meet , It's also detailed that they have dedicated large-scale real machine testing to check compatibility . On the one hand, the overall answer is OK , It's almost nothing to do with Android Related issues ; Because it's a telephone interview , I didn't ask any arithmetic questions .

Two days later, I got a call from the second side of the internal push . About two sides 50 minute , The main question is Java GC Mechanism 、Android APP The boot process 、Android Event distribution 、Android View Drawing process .GC I've just read the mechanism, so I'm quite good at answering it , However, because Ali started the interview too early , I haven't had time to review Android, therefore Android The answers to the related questions are very confusing , such as APP The start-up process just faltered ,View I don't know the drawing process , Tell the interviewer I know Android Event distribution process , So I talked about everything in detail for a long time , Finally, I make complaints about the Tucao Android. At last, I asked the interviewer about the domestic mobile phone manufacturers Android Framework What's your opinion , The interviewer replied that he was helpless too , But Ali generally cooperates with mobile phone manufacturers , Go straight to the white list , So I didn't have a big problem .

It took more than a week to get a call from three sides after two sides were pushed , And on weekend nights 11 A.m. . Three sides, about 20 More minutes , I mainly asked about the projects I have done 、Java Basics 、 Recent books 、 What do you want to learn when you go to Ali . I'm not sure if this round of interview is technical or HR Noodles , Because it's night 11 Point and female ticket just returned to the hotel, completely out of state , And the interviewer seems to be impatient , In addition, I have been preparing for technical problems during that period HR I'm totally unprepared for face-to-face problems , So the answer is very wordy and bad , Many of them didn't get to the point . Finally, I asked the interviewer how I did , The interviewer was impatient and didn't hang up .

After the end of the three sides of the push, I think it should be hung up , And then for another week , From the official website “ During the interview ” become “ Has refused ”.

When the official batch of Ali started, the official batch was put in , There is a unified written test for official batches , Ali's own system for the written test ; I can't remember the content of the written test clearly , But ten or twenty multiple choice questions have deep memory , A lot more than Android Related knowledge topics , A lot of intelligence problems that can't be solved .

Only a few people seem to have passed the formal written test （ The main reason is that there are few jobs in the official batch ）, Fortunately, I also passed , After making an appointment for the interview on the official website, I started to prepare the video , The interview department is nail （ Like I said before , The official batch of departments are relatively marginal ）.

The formal side is the video interview , Probably not 20 minute , It's the second worst interview for my internship in autumn . The main question is Activity Time consuming operations can be performed in （ Namely UI Thread related ）、Android What are the memory leaks in , And then there's sharing screens and writing code ： Realize the insertion, deletion and search of single linked list . Why is the experience so bad ？ First of all, the whole interview asked two questions , And almost any of these two questions has Android All those who have developed experience can answer like a stream , And I don't have it after I answer , I didn't go any further ; Secondly, the code in the data structure textbook when talking about the linked list will say , And there's no technical content . Finally, the interviewer said it was OK , It's over without me asking him questions .

One day later, the state of the official website becomes “ Have turned down ” 了 , I'm very tired. I don't think I can love again .

US group review

Meituan's comments have been applied online for a long time , In fact, it was originally pushed by elder martial brother , However, at that time, the post of internal promotion was backstage development , After thinking about it carefully, I changed it to Android Development , So it's not extrapolation （ I didn't understand this until I failed the written test ）.

After that, I received the unified written examination of meituan's comments , Meituan reviews are based on the Beisen system , It's amazing . I can't remember the written test , Finally, there is a programming problem , It's like finding the longest increasing subsequence , Classic title . At that time, I felt that the written test was very good , However, there is no news after the written test , It's a black question mark .

Later, I thought that maybe it was when I applied online , choose “ Interested business groups ” Yes “ All interested in ” As a result, no business group is interested in me , We'll talk about that later .

Netease game

Strictly speaking, I vote for Netease Entertainment （ Different from thunder fire & Pangu , I'll talk more about the difference later ）, The inner push of walking . Netease game is famous for its difficulty in written test , This is no exception ; All extrapolations require a unified written test , I remember a few written tests , I was in the first . The post of internal promotion is the core of Netease game “ Game Development Engineer ”, The location is Hangzhou .

Niuke platform for written test , Big praise . There are four programming problems in the written test , altogether 150 minute , It's very difficult , The first three questions don't use any advanced algorithm , But we need to think of solutions , The last problem is a multiple knapsack problem . I passed three and a half questions in the written test , Because the last question I don't know why the memory is out of limit , With primary int And dynamic planning , In theory, there is no memory overrun . I'm almost sure that I can enter the interview after I finish the written test , At that time, I had a hunch that if I could do two questions, I could enter the interview , Later found that many people only made a question into the interview .

Netease game intern recruitment is very magical is the whole round of interview ,HR There is no face . An interview is a video interview , Niuke  

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  Web platform , About an hour or so . The interview is to ask the four major computer courses in turn , Asked Java Language foundation , Finally, I asked an algorithm problem .

The four major courses ask the basic questions , But there are some deep questions , The basic image asks the best of all sorts of sorting algorithms 、 Average 、 Worst time complexity 、 The difference between threads and processes 、cache working principle 、 Seven layer model of computer network ; It's like asking how many stacks there are in the process 、 How many stacks are there in the thread 、 Blocking refers to process blocking or thread blocking 、 On a server TCP and UDP Monitor whether the port number can be the same 、 The server 80 After the port and the client establish a connection, whether the port will be switched, etc .

Java Language foundation, here's an episode , The interviewer didn't expect me to C/C++（ Because the job description has to write C/C++, But only any two of the five requirements can be delivered ） It's just Java and Python, So he had to ask some questions Java The problem of language basis , such as Integer and int The difference between 、GC The working process of the project ; And asked Python The principle of the decorator , I just talked about aspect oriented programming ; Finally, the interviewer felt that he didn't ask C/C++ no way , Then ask me if I know C/C++ The virtual function in , I turned it down . Finally, I asked an algorithm problem of string circular movement , It's a classic topic , Just say it orally three times .

Finally, I asked the interviewer that the job introduction required that C/C++, But I think it's mentioned in the introduction of the recruitment website Python, What languages are used in practice ？ Interviewer said C/C++ It's mainly used in the game engine , The development is mainly able to use Python. Although some questions have not been answered or have been answered wrong , But on the whole, the answer was very good , Anyway, for me, I've reached the limit . I feel like this after the interview offer It's almost there .

It took me more than two weeks to get a copy of Netease games offer, But it's also the first one I received for intern recruitment offer, It's also a very important one , Since then, my intern recruitment has a solid foundation .

Last

Considering the length of the article , I have made these questions and answers, as well as the questions I have encountered in my interview for many years and some interview materials PDF file

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