The computer is out of power. How did I pass the terrible interview of Tencent cloud?

First of all , This article is the summary of the author's interview with Tencent cloud Regional R & D company today

After introducing yourself, the interview begins , The platform is Tencent conference .

Problem.

1. The interviewer asked me to do two questions , Write a for the first question memcpy, The second question is to write the preorder traversal of binary tree ( The structure of the tree is given by the interviewer , The call has a travseFun A function pointer , Call the callback function )
   finish writing sth. memcpy, The interviewer asked me if I thought about it ( I didn't say it here , I felt like I was going to hang up ) The interviewer directly asked the second question ;
   Preorder traversal is simple , Recursion and iteration .

2. What's wrong with the recursive traversal of binary trees ？( Answer the memory problem that may cause the call stack to be too deep )

3. The user-defined stack is used in the iterative traversal of binary tree , Characteristics of stack type , Realization ？（ Answer first in and then out , Sequence table implementation , Linear table implementation ）

4. C++ Why do destructors use virtual modification ？（ The dynamic creation of subclass objects by base class pointers causes memory leakage problems ）

5. The difference between heap and stack ？（ From two aspects of call and memory distribution ）

6. Interprocess communication ？（pipe, fifo, signl, mmap, socket, And specify whether it is full duplex , And advantages and disadvantages ）

7. UDP and TCP The difference between ？（ Everyone on earth knows that ）

8. TCP Why is it called Streaming Protocol ？ How do you define flow ？（ from TCP The connection and disconnection of , Let's talk about socket Knowledge of network programming in creation ）

9. TIME_WAIT Why two MSL Time ？（ In general FIN The loss of , And port reuse ）

10. Difference between process and thread ？（ combination Linux For its realization point ）

11. What is paging error ？（ I have studied the principle of computer composition ... But forget , I don't really remember ）

12. Database paradigm ？（ Three paradigms , Each paradigm is introduced in detail ）

13. Database index ？（ Combined with the project , Used to primary_key, unique, index etc. ）

14. Trees in C++ Application in , Properties of red-black trees , The time complexity of adding, deleting, checking and modifying red black trees ？（set, map, Definition of red black tree ,Log N）

15. Is there a data structure that can make the search performance constant ？（ Hashtable , And introduced in detail STL Hash table implementation of ）

16. Why not use the red black tree for the database B+ Trees ？（ Start with disk , To B+ The advantages of tree data structure ）

17. If there is a joint index by ( Time , full name ), Now just look up the name, will you use the index ？（ Left most matching principle ）

18. The difference between virtual memory and physical memory , contact ？（ Middle layer , as well as linux The general implementation of virtual memory ）

project

There are two items in the resume , However, the interviewer said there was nothing in my resume to read .... Just ask me if I have ever done a project with my teacher . I said I had done a community QR code registration system .

1. Do you use encryption methods in your project , If you use encryption, which encryption method would you use ？（ Not used , If it can be used, one is simple encryption ： For example, letters a+3, And then decrypt a-3; There's another one MD5 Or hash ）
2. Whether the QR code considers the problem of information conflict ？（ No, ... Embarrassment ）

summary

These last... About 1 Hours 45 minute I feel that the interviewer has to ask a lot of questions , But because my computer has no electricity, I shut it down ... Then I felt like I was using my cell phone to enter the meeting , The interviewer said that today's interview is over , Didn't ask me any questions , I didn't say to prepare for the follow-up interview , I thought it was so cold .

As a result, I received two notices when I returned to the dormitory , Come on, come on, come on ~