operating system

Processes and threads, how to synchronize threads (speaking of semaphores, signals) (should be thread communication), the interviewer smiled contemptuously:
Does it need to be so troublesome? After reminding me, I talked about shared memory.
Asked the thread scheduling algorithm written in the project , I asked how job duration is judged in SJF, but I didn’t answer it.

7. The difference between process and thread
8. The difference between kernel mode and user mode

database

Database engine
Clustered index and non-clustered index function

I heard that the covering index is useful in the project, and asked what the covering index is

Simple sql question, because I haven’t written it for a long time, so I talked about the idea
id and score, and gave a new score. I want to know the ranking of this score.

computer network

Then OSI7 layer model, TCP/IP4 layer, and five layers talk about
the composition of HTTP messages

Jiwang:
The review of this part is not very good. I was asked to be confused about the
OSI seven-layer model and the protocol of each layer.
Who is on the network layer and the transport layer?
TCP and UDP are applied separately
? Is TCP safe (said security, interview Officer: Are you sure, I’m stupid)
Later, you said all about the reliability of
TCP , not security. How can TCP guarantee reliability? (Answer slow start, prepare to continue, be interrupted)
Ask what is the purpose of slow start (No answer)
Do you know the difference between HTTP and https
HTTPS encryption process? (never heard of that)

5. What do you know about the Http status code?
6. Because I said 301 and 302, I asked the difference between the two (the interviewer also explained it again)

1. The difference between the three-way network handshake tcp and udp (dug a bit, but I will not)

During network transmission, the sequence numbers of the client and server data packets change.
7. Do you understand http.

data structure

HashMap talk about

3. The difference between B+ tree and B tree
4. MySQL topic: judging index usage

Algorithm question

First introduce myself, and then tear up an algorithm problem, factorial of large numbers, it is too silly to write it out. I
changed it, and the path in the matrix was adapted.

K flip list

9. Algorithm question: Jump up the stairs, write recursion and dp (it has been a long time to calculate the time complexity when using recursion, it's too cumbersome)
10. Mathematical thinking question: ABCDE pirates, they want to divide up 100 gold coins. ABCDE, take turns to propose, the proposer needs to get half a vote or more, otherwise he will be killed, the next one continues to propose, how will you be assigned if you are A

Longest common prefix

Given an integer, output the string corresponding to the 36 base.
2. One hundred thousand (one hundred million) Guangdong candidates' scores, find the median.

(Supplement) The minimum number of the interval times the maximum value of the interval sum, a high-frequency interview question with byte beating

C++ basics

Why use shared_ptr instead of auto_ptr now.
4. Why use make_shared instead of using new directly.
5. Use scenarios of weak_ptr, why is weak_ptr needed?

other

Asked about the project, introduced the design of the database table, the technology stack used, etc.

No projects (all written in class)
Often: 35min
may not ask any questions because the interviewer does not write java

The difference between select and epoll.
8. Give a function to write it as a lambda expression, what is the difference between & and = in the capture list, and what capture is the default.
9. Are you familiar with STL? The answer is familiar but did not ask.
10. Open the question. I get stuck when I try to use the vibrato. What could be the reason.
11. Do you know about audio and video? I don't know anything about the answer, but I still ask me what kind of frames there are. . .
11. Tucao project is too simple, does zeromq understand.
12. Interview feedback: I said that my algorithm is pretty good (but I didn't actually work out both questions), and the network foundation is relatively poor (really).