Sharing of Alibaba interview abuse experiences, and Alibaba interview abuse

Sharing of Alibaba interview abuse experiences, and Alibaba interview abuse

I was so worried about this interview. On the evening of the 14th, I attended the test at the Union University. Then I waited for the interview notice, but I didn't notice it at noon, so I really couldn't sit down, I went to the hotel for the interview and asked, they said that the notification had not been sent, and they were not in the mood to wait. I told them to see if they could directly go to the interview, just a few java interviewers are idle, so I arranged for an interview. The interview lasts for more than an hour. I also asked a lot of questions and asked the questions very carefully, but the interviewer was also patient. Next let's talk about the interview questions:
1. First, introduce yourself;
2. Then I checked my internship experience and asked questions about my internship program. My internship was about Oracle ADF, so I asked me what I was about Oracle ADF, how to implement it, balabara said a bunch of things.
However, after more than a month of practice, I did not know much about many things, so I guided the interviewer to ask about struts2.
3. Next I asked about struts2:
1) How struts2 is implemented, how it works, and so on. The answer to this question is very good, because it is well prepared.
2) What is the implementation of session? This should be the implementation of the ActionContext object. Where is the storage? This problem is stunned. No, I don't know. I just know where it is stored on the server? Memory or where? Not clear.
After answering these questions, I opened the question. I said that the web project has not been completed for more than half a year. Recently, I prefer to study the basics of java, jdk, source code, and so on.

4. Well, let's look at the java basics:
1) understand the linked list. How to Create a linked list. Sorry, no problem. We have implemented this. I used protected to declare the keyword information in the Node linked list class.
2) as soon as I saw my declaration using protected, I began to ask my protected, access permission. Do you think the Linked List class I wrote can access the protected domain in Node? I said yes, in the same package.
3) Then I asked several keywords with access permissions. Do you know? Of course, I know the order of access permissions, and I am trying to correct the order... Bad
4) then, ask me which lists I have used? I said that ArrayList, vecloud, LiskedList, Map, Set, etc. Then I asked the Set framework question. Then I asked HashMap how to implement it? First, the array, and then the linked list storage. Many questions are frequently asked during interviews. I thought this was the last question. Then I started to ask again, since it is stored in the linked list of arrays, so how do I know where the array is stored? Then how does the get method take the value? Do I retrieve the array step by step?
5) I don't know. Is it traversal? I should have said no in my mouth. By the way, I smiled. He also smiled. I did not understand it for a long time, and then I changed my topic;
6) after asking about Set, TreeSet, and LinkedHashSet, I knew their functions. So I just understood their functions, and I didn't know much about the source code, then, let's talk about their respective functions;
7) Then I asked about the content of the List interface and explained the differences between ArrayList and sorted List. I also talked about the differences between ArrayList and sorted List;
8) then, I asked which books I have read. I mentioned introduction to algorithms and java programming ideas, and then I asked nio's questions. I have read these questions and can read big data, but I forgot how to implement it. I only remember the channel or something.
9) I asked another algorithm question:
The question is: how does one know the number of 1 binary data of 32 bits when int data is 32 bits?
I spoke about my ideas. One traversal is not very good, but the other method is to shift to the left and determine whether it is a positive number or a negative number after the shift. Then he said, well, what should he do if he shifts to another place? I thought about the result after the last bit and the operation, judgment and operation.
Later, the interviewer said: Well, the java basics are still available. Let's look at the operating system.
5. The operating system won't be wiped. I said that I learned the operating system when I was a sophomore, but I didn't catch a cold at the time, so I learned a little about it. He asked, why not catch a cold? I said that I was just getting started with programming, so I felt very hard to understand and understand the memory management knowledge of the operating system, and so on. Then I talked about two simple problems, mutex and semaphores. I want to talk about these two things. If I was in my sophomore year, I would definitely be finished now. I haven't seen them for a year or two. I forgot to drop my ass, what's more, I have told you that I am not familiar with the operating system. Why do I have to ask? What do I ask? Then, let's talk about the difference between a process and a thread. If no one is prepared, you will know that you will take the test. balabara said a few differences to get it done.
6. What about network? I also learned from my sophomore year. Now many of them are blurred. I asked my questions about the three-way handshake, the principle, the process, and the process. I forgot. Have you told me that I have learned the http protocol? I said that I must have learned this kind of knowledge from the Internet, but now my memory is a bit vague. Then he asked, What is the http protocol? I still asked questions. Or what operations do I do after entering an address on the website? I also know about domain name resolution. What about Bala? What then? After arriving at the server, what does the server do? What does the server do? What do I know? It's not about web server operations! What else can I do? Not clear.
7. Well, there's no way to do it on the Internet. Let's ask a few more algorithms. Okay, let's talk about quick sorting. balabara talked about a bunch of things and gave him a picture to demonstrate it. good. What about complexity? Average complexity and worst complexity, including space time.

8. What is the complexity of sorting? Barabara said again, algorithms, sorting algorithms, but no one is ready to interview again.
9. Good. Then I asked about data. I said I used oracle and mysql. After chatting, I told you that I would use SQL. Would you like to know about indexes? What are oracle indexes? Do I have B-tree indexes or Bitmap indexes? He said yes, right. I don't know much about it. I only know such a thing. However, indexing is really a good thing. It is useful to search for small data from big data.
10. Then I asked about the hash function. What should I do? I don't know, but I moved the topic to the hashCode I just asked, q: How can arrays and linked lists in HashMap be stored? If an object is stored, where can I store it? We all know that if hashcode is the same in an array, the position of the linked list exists. But how can this problem be achieved? This is unknown. How do you design a storage method? I don't know. I still smiled ....
11. Finally, I asked a question about the data structure,
The question is: an array stores many English letters. Q: How do I know which of the 26 letters are not stored?
After a long struggle, I thought about several solutions. The first one was to traverse them one by one. It was definitely not a good method. Later, I found a solution that could not be used to delete one. Finally, he prompted, you can use multiple spatial solutions.

I have asked a lot of questions about this interview, and my knowledge scope is very narrow. I don't know much about operating systems and computer networks. Alibaba's interview is really sad...


No matter whether you do, as long as you dare to write on your resume, he will dare to ask you.