Shulou(Shulou.com)06/01 Report--

The subject does not write about which position he is looking for, even if it is a technical post, if it is in different directions, such as C++ and Java, the written interview questions will be different.

It doesn't matter if the subject doesn't write. Here we will choose a few positions with a large number of job seekers and more popular positions, and list their interview sites and summarize them to everyone.

Here is a summary of the written interview sites for C++, Java and machine learning / algorithm positions, as well as the front-end positions and test positions. If you want to see these two directions, please pull them directly to the bottom.

(PS: there are answers to these summaries, ha. the answers are summarized at the end of each part.) C++ Direction 1, basic knowledge 1, basic language

1. Talk about the function of the static keyword

2. Talk about the difference between C++ and C

3. Talk about the role of the static keyword in C++

Please talk about the function of static

5. Talk about the four cast conversions in C++

6. Please tell me the difference between pointers and references in CUniverse +.

7. Given the triangle ABC and a point P (XMagneyMagnez), determine whether the point P is in the ABC, give the idea and write the code by hand.

8. How to judge that a number is a multiple of two, and how to find out how many ones there are in a number? tell me your idea and write the code by hand.

9. Please tell me what you understand about the four smart pointers of smart pointer in C++

10. Please answer the difference between array and pointer

11. Please answer what the wild pointer is

12. Please introduce the smart pointers in C++

13. Please answer whether there is a memory leak in the smart pointer

14. Please tell me how to solve the memory leak of the smart pointer.

Please understand the references and pointers in C++

16. Please talk about the smart pointers in C++

Please answer why the destructor must be a virtual function and why C++ 's default destructor is not a virtual function

18. Please tell me about the function pointer

19. Please tell me about the fork function

Please talk about the role of destructors in C++

21. Please tell me the difference between static functions and virtual functions

22. Please tell me about overloading and overwriting

23. Please talk about the static keyword

Please tell me something about strcpy and strlen

25. Please tell me about the virtual functions and polymorphisms you understand

26. Please answer the difference between + + I and iTunes +

27. Please talk about the implementation of + + I and iTunes +.

28. Please write a function to run before the main function is executed

29. A piece of code is written as follows: if you change only one character, make the code output 20 hello

30. Please talk about the implementation of smart pointer shared_ptr

31. What is the difference between the following four lines of code

32. Could you tell me how constant is defined in C++? Where are the constants stored in memory?

33. Please answer what is the purpose of const decorating member functions?

34. Will there be a problem if two functions are defined at the same time, one with const and the other without?

35. Please tell me about implicit type conversion

36. Tell me about the type conversion you know.

37. Please talk about the maximum value of C + function stack space.

38. Please say something about extern "C"

Please answer what is the difference between new/delete and malloc/free

Please tell me what you know about RTTI

41. Could you tell me exactly how the virtual function table implements runtime polymorphism?

42. Could you tell me how C language makes function calls?

43. Could you tell me the stack order of C language parameters?

44. Could you tell me how C++ handles the return value?

45. Would you please answer whether the parameters of the copied assignment function in C++ can be passed on?

46. Please answer the difference between malloc and new

47. Please say something about select

48. Please talk about the fork,wait,exec function

49. Please answer the difference between static function and virtual function

Please talk about overloading and overwriting

Please say the keyword static

Please talk about strcpy and strlen

2. Containers and algorithms

1. Please tell us the difference between map and set and how they are realized.

2. Please introduce STL's allocaotr

3. Please talk about STL iterator deleting elements

4. Please talk about the storage form of MAP data in STL

Please tell me what is the basic composition of STL

6. Please talk about map and unordered_map in STL

7. Please talk about the difference between vector and list. The more detailed the application, the better.

8. Please tell us the role of iterators in STL and why you need iterators with pointers.

9. Please talk about the principle of epoll

10. Please tell me how the STL iterator deletes elements

11. Please talk about the storage form of MAP data in STL

12. An unordered array of n integers to find the first number larger than it after each element, requiring a time complexity of O (N).

13. Please answer the difference between resize and reserve in STL

Please tell me how to implement set and map in stl

3. Class and data abstraction

1. Please talk about the access rights of class members in C++.

Please tell me the difference between struct and class in C++

3. Can you define reference data members in C++ class?

4. Object-oriented and generic programming

1. Please answer what is the right value reference and what is the difference between the right value reference and the left value?

5. Compilation and bottom layer

1. Please tell me about the process of a C++ source file from a text to an executable file.

2. Would you please answer the order of the header files and the difference between double quotation marks and angle brackets?

3. Please answer the principle of malloc, and what is the function of brk system call and mmap system call respectively?

4. Could you tell me what the memory management of C++ is like?

5. Please tell me about the memory allocation of Centralink C

6. Would you please answer how to judge the memory leak?

7. Please tell me when an error will occur.

8. Please answer what memory leak is, that is, memory leak

9. Please answer the difference between new and malloc

10. Please tell me something about shared memory related api

11. Please tell me about the composition of the reactor model

12. Please design how to deal with high concurrency in a single-threaded way.

13. Could you tell me how C++ handles memory leaks?

14. Please talk about the differences, principles, performance and limitations of select,epoll

15. Please talk about the memory optimization of C++ STL

6. Central11

1. What are the new features of Category 11?

2. Please introduce in detail the new features of variable parameter template, right value reference and lambda in Clover 11.

II. Operating system

1. Please tell me the concept of process and thread, why there are process threads, what is the difference between them, and how they are synchronized.

2. Please talk about the Linux virtual address space

3. Please talk about the memory structure of the programs in the operating system

4. Please talk about the missing page interrupts in the operating system

Please answer the difference between fork and vfork

6. How to modify the maximum number of handles in a file?

7. Please talk about concurrency and parallelism

8. What is the port number of MySQL and how to modify it

9. Please talk about page table addressing in the operating system

10. Please tell me why there are threads when there is a process.

11. When writing multithreaded programs on a single-core machine, do you need to consider adding locks? why?

12. What context does the thread need to save, and what are the registers SP, PC and EAX for?

13. Please talk about the synchronization mode between threads, and it is best to specify the specific system calls.

14. Please tell me the difference between multithreading and multiprocess

Please tell me the difference between a process and a thread

16. Should the game server open a thread or a process for each user? why?

17. Please talk about the OS page replacement algorithm

18. Please tell me the difference between process and thread

19. Please tell me about the usage scenarios of multi-process and multi-thread.

Please talk about the conditions under which the deadlock occurred and how to solve the deadlock

21. How do virtual memory and physical memory correspond

22. Please talk about structure alignment and byte alignment in the operating system

23. How to communicate between processes

Please tell me the way of virtual memory replacement

25. Please talk about several ways of multithreading and thread synchronization

26. Please talk about the mechanism of mutex and the difference between mutex and read-write lock

27. Please answer the difference between process and thread

28. Please talk about the process state transition diagram, dynamic ready, static ready, dynamic blocking, static blocking

29, AA = new A; a-> I = 10; what happens to memory allocation in the kernel?

30. I'll give you a class with static,virtual and so on. Let's talk about the memory distribution of this class.

31. Please answer the difference between soft links and hard links

32. What is the big end and how to judge the big end and the small end

33. Please answer when the static variable is initialized

34. Please tell me the difference between user mode and kernel state

35. How to design server to receive requests from multiple clients

36. The method of creating a new thread when connecting is a bit inefficient. How to improve it?

Could you tell me how to wake up the blocked socket thread?

38. How can I determine whether the current thread is busy or blocked?

39. Will idle processes and blocked processes be misjudged when waking up?

40. What is the ready process waiting for?

41. Please talk about the synchronization of multi-thread and the mechanism of lock.

42. Will both processes acquire spin locks when they access critical zone resources?

43. assuming that critical zone resources are released, how to ensure that only one thread gets critical zone resources and not all of them?

44. Do you know the windows message mechanism? please talk about it.

45. How many locks do you know for C++?

46. Tell me about the locks you use

47. Would you please tell me the necessary conditions for deadlocks to occur?

48. Please tell me what threads and processes, multithreading and multiprocess communication are.

49. Please talk about memory spills and memory leaks

50. the difference between processes and threads, what thread model do you use?

51. Please tell me about the cooperation process.

What are the system calls and what system calls have you used

53. Please write an example of fork call by hand

54. Please talk about the principle of transformation from user state to kernel state.

Please tell me the process from the source code to the executable file

56. Please tell me about the micro kernel and the macro kernel

57. Please tell me about the zombie process

58. Have you used GDB debugging? what is a conditional breakpoint

59. Please introduce five IO models

60. Please talk about the event loop of asynchronous programming

61. Please answer why the operating system should distinguish between kernel mode and user mode.

62. Please answer why there is page cache and how does the operating system design page cache

63. The server listens to the port, but no client is connected yet. What state is the process in at this time?

64. How to design server to receive requests from multiple clients

65. The method of creating a new thread when connecting with a dead loop is a bit inefficient, how to improve it?

66. What are ready processes waiting for?

67. Please talk about the synchronization of multi-thread and the mechanism of lock

68. Will both processes acquire spin locks when they access critical zone resources?

69. assuming that critical zone resources are released, how to ensure that only one thread gets critical zone resources and not all of them?

70. How to implement thread pool

71. How to get 100 to 200 lines of a file under Linux

72. Please tell me about the use of awk

73.Please talk about the Timer timer mechanism in the linux kernel

III. Computer network

1. Your research direction is wireless sensor networks. How to ensure the reliability of node transmission and storage?

2. Please explain how TCP ensures reliability, and briefly describe the process of establishing and disconnecting TCP.

3. Please talk about the model of TCP, state transition

4. Please answer the difference between HTTP and HTTPS, and what are the shortcomings of HTTPS?

Please talk about the difference between http and HTTPS

6. Please tell me the HTTP return code

7. Please talk about the function of IP address and MAC address

8. Please introduce the interrupts in the operating system

9. Please answer the OSI seven-layer model and the TCP/IP four-layer model, and list 2 protocols in each layer.

10. Please tell me the process and reasons of TCP's three-way handshake and four waves

11. What layer in the computer network will be used to search for baidu? What does each floor do?

12. Would you please talk about TCP congestion control? And at what point does it begin to slow down the rate of growth?

13. What measures does TCP take to ensure its reliability

14. Please talk about the interaction process of TCP/IP data link layer

15. Please tell me how to pass to the IP layer how to know which application the message should be sent to, and how it can distinguish between UDP message and TCP message.

16. Have you ever developed based on socket? How to do the operation of the specific network layer? (it is actually the basic step of network programming)

17. May I ask the server terminal to listen to the port, but no client has connected yet? what is the state of the process at this time?

18. What is the three-way handshake for TCP?

19. Why can't tcp shake hands twice? Why not four times?

Could you tell me something about TCP congestion control?

20. The difference between TCP and UDP and their respective applicable scenarios

21. Please tell me how TCP shook hands three times and waved four times, and why it takes three times for tcp connection to shake hands, time_wait status.

22. Please talk about the http protocol

Please tell me the difference between GET and POST

Please tell us which functions are mainly used by the server and the client in socket programming

25. Please tell me what the digital certificate is and what it contains

26. Please introduce UDP's connect function

27. Would you please tell me about TCP's three-way handshake, four waves and why you use a three-way handshake?

28. Please talk about blocking, non-blocking, synchronous and asynchronous

29. Would you please talk about the send () recv () accept () socket () function of Socket programming?

30. Could you tell me how to intercept the end sign of http session?

Please tell me about the three handshakes

32. Please say four waves

33. Please talk about the interaction process of TCP / IP data link layer

Database 1, database foundation

1. Please talk about database transactions and four features

2. Please talk about the three paradigms of the database

3. Please introduce the ACID features of the database.

4. Please talk about the database index

5. Please talk about database transactions

6. Please talk about database transaction isolation

7. Please talk about inner join and left join

8. Please talk about the consistency of database things.

9. Please tell me what the index is, and will it be good to add more indexes?

10. What are the requirements of key in KMurv storage?

11. Introduce the WAL technology in the database

2 、 Mysql

1. Please talk about the four isolation states of mysql

2. Please introduce the MVCC mechanism of mysql

3. What are the SQL optimization methods?

4. Please tell me about the MySQL engine and the difference

3 、 Redis

1. Please answer the difference between mongodb and redis

2. Please tell me about the mysql engine and its difference

3. Please tell us how the timing mechanism of Redis is implemented.

4. Please say that Redis is single-threaded, but why is it so efficient?

5. What are the data types of Redis and how to implement them at the bottom?

6. How is Redis's rehash done, why is progressive rehash, and how is progressive rehash implemented?

7. Please tell me the difference between Redis and memcached

8. How does Redis realize the function of deleting periodically?

9. Please talk about the corresponding command and data type of Redis.

Algorithm and data structure 1. Tree

1. Please talk about the definition and characteristics of red-black tree and AVL tree, and the difference between them.

2. Please talk about Huffman coding

3. Please answer why the bottom layer of map is implemented with red-black tree.

4. Please introduce the B+ tree

5. Please talk about the underlying implementation of map and unordered_map

6. Please answer the advantages and disadvantages of map and unordered_map

7. Please answer how epoll is realized

8. Please talk about C++ and two kinds of map

Do you understand the red-black tree?

10. Please talk about the nature of the red-black tree and the rotation from left to right

11. Could you tell me the principle of the red-black tree and the specific distribution of iterators after erase?

12. Please realize the sequence traversal of the binary tree and output

13. Handwritten code: binary tree serialization and deserialization

2. Stack and stack

1. Please talk about the stack overflow you understand, and give a simple example that leads to stack overflow.

2. Please answer the difference between stack and heap, and why the stack is fast

3. Handwritten code: two stacks implement a queue

4. Please tell the difference between heap and stack

5. Please talk about the characteristics of the small root pile

3. Array

1. Please answer the difference between Array&List, array and linked list

two。 A shaping array of length N, and the value range of each element in the array is [0memnmur1]. To determine whether there are duplicate numbers in the array, please tell me your idea and write the code by hand.

4. Sort

1. Please write the code of express arrangement by hand.

2. I would like to ask the method of finding the largest number of k and what is their complexity. In addition, when there are the same elements, what different methods can be used to find the largest element of k?

3. Please introduce various sorting algorithms and time complexity.

4. Please tell me about the sorting algorithm you know and its complexity

5. May I ask how to get the largest k of massive data?

6. Please talk about the Top (K) problem

7. What is the worst time complexity of fast queue? When is the worst time?

8. What are the stable order?

9. Please introduce the fast arrangement algorithm; and what is the stability sort? is the fast arrangement stable? the worst case derivation formula of the fast arrangement algorithm

5. Hash

1. Please talk about the implementation of the hash table, including the hash bucket length constant in STL.

2. Please answer how the hash table is rehash and what to do with the resources stored in it.

3. Would you please tell me why the number of buckets in the hash table is prime and what's wrong with the combined number?

4. Please tell me how to resolve the hash conflict

5. Please talk about the solution to the hash conflict

6. Dynamic planning

1. Please write the code by hand: the longest common continuous subsequence

2. Handwritten code: find the longest text substring of a string

3. Handwritten code: find the longest reply substring

7. Linked list

1. Please write your handwritten code on how to merge two ordered linked lists.

2. Handwritten code: reverse the linked list

3. Determine whether a linked list is a palindromic linked list, state your ideas and write the code by hand

4. Please reverse your handwritten list

5. What is an one-way linked list and how to judge whether two one-way linked lists intersect

7. Advanced algorithm

1. If you were asked to do natural language understanding (NLU), what algorithm would you probably use when dealing with language rules?

2. What are the encryption methods?

3. What is LRU caching

4. Please tell me about the shuffle algorithm

8. String

1. Give you a string and find the first character that does not repeat, such as "abbbabcd", then the first character that does not repeat is c

VI. Project-related

1. Please answer the difference between Merge and rebase in git

7. Design pattern

1. What design patterns have you used, and introduce the multi-thread safety of singleton patterns?

2. What design patterns do you know?

3. How to ensure that the singleton model has only one instance? What methods do you know?

4. Please talk about the five principles of OOP's design pattern

5. Would you please tell me the advantages of the factory model?

6. Please tell me about the observer mode

7. Please introduce the singleton model

8. Lazy loading in singleton mode, what should I do if I access concurrently?

9. Decorator mode and singleton mode, what should be paid attention to when using singleton mode

VIII. Scene questions

1, give you two balls, 100 floors, each ball thrown at a certain height will be broken, how to use the least number of times to judge which floor can break the request?

IX. Distribution and Architecture

1. Design of distributed cache and distributed storage.

For the answers to the C++ test sites, please see here:

Attach C++ knowledge points, mind maps and answers.

Summary of machine learning / algorithm school enrollment interview test sites (attached questions and answers) [continuously updated] _ written face _ Niuke.com www.nowcoder.com

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Due to the limitation of space, we can only put it in these three directions for the time being.

In addition to these three directions, Niuke has also summarized the test sites of the front end and test posts, and the 50W words are all here (with answers):

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