Summary of morning questions for intermediate software designers
foreword
I prepared for the intermediate software designer exam at the end of October and the beginning of November. The total preparation time for the exam was 20 days. Since the reserved time for the exam is not much, the review strategy for the morning questions is mainly to read the notes organized by others. The video of zst_2001 was supplemented, and finally reserved 5 days to prepare the afternoon questions and write the real questions in the morning. In the morning, I did 700+ real questions. This blog is in the final stage of doing the real questions. I personally think that the knowledge points that are more difficult to memorize need to be recorded. , to avoid rework due to forgetting, and reviewed this note 2~3 times in the last night.
After the exam in early November, I wanted to wait for the results before sharing this note. Today, I just revived the note script and processed all the previous notes together. The results will be released at the end of December, so I took advantage of the convenience to release them in advance.
Here I would like to thank zst_2001, the up master of station b: zst_2001 personal homepage
, thanks to the creator of zst_2001 video notes @肖戴:软考Notes
This blog extracts part of the content of @肖戴Notes, the original intention is to facilitate personal study, if there is any infringement, please contact The author will delete it immediately!
1. Assembly line
Throughput rate = number of instructions / [time of a complete instruction + (n-1) * pipeline cycle]
The total time of the pipeline = the time of a complete instruction + (n-1) * pipeline cycle
The pipeline cycle is the segment with the longest execution time (the most time-consuming)
2. IP address block
The address code reserved for the host in the IP address block is only 6 digits
IP26 is in the format of CIDR, and its full name is classless inter domain route.
These addresses are all in the form of 222.125.80.10xxxxxx, where the minimum address is 222.125.80.10000001, which is 222.125.80.129, and the maximum address is 222.125.80.10111110, which is 222.125.80.190
**Note:**In the IP address, all 0s represent the network, all 1s represent the broadcast
3. Relational schema candidate key
4. Floating point representation
Examine the representation of floating point numbers. Floating-point number representation: = mantissa * base exponent
where the mantissa is represented by the original code, which is a decimal. According to the table and the question stem, 00000000001 is the mantissa part, with a total of last 11 digits, of which the first digit is 0 to indicate a positive number, which can be expanded to The 2-10
order code part is represented by complement code, which is an integer. It can be seen from the table and the question stem that 10001 is the integer part, with a total of the first 5 digits. To calculate its specific value, it needs to be converted into the original code, through the first digit Sign bit 1 shows that it is a negative number, complement code: 10001, inverse code: 10000 original code: 11111, the data is -15, the base number is expressed as 2 in floating point numbers, and 2-15×2-10 can be obtained
Note : The order symbol indicates the sign of the exponent, the exponent is an integer, the number sign indicates the sign of the mantissa, and the mantissa is a decimal. The mantissa part is actually 0.xxxx, here is 0.0000000001, which is 2-10
4. Storage
Read and write storage: RAM
Read-only storage: ROM, PROM (programmable), EPROM (erasable and programmable), EEPROM (electrically erasable and programmable)
Flash: Similar to EEPROM, the difference is that it can be deleted and rewritten at the byte level instead of rewriting the entire chip. Data can be saved when power is off.
5. Semaphore mechanism and PV operation
The value of S is a negative number, and there are several processes waiting for negative numbers. The value of S is 0, which means that there are no waiting processes, but one or more processes are running. If S is a positive number, it means how many resources are available.
Here, I understand it as entering p and exiting V (into fart) for such a topic, that is, observing the graph, if the in-degree is the P operation, and the out-degree is the V operation, for example, P1 in the above picture has two out-degrees , that is V(S1) and V(S2), for P2, one in-degree and one out-degree, so it is P(S1) and V(S3), so before doing the question, first mark S1 on the one with To the side, note that I am just doing the questions quickly. This statement itself is not normal, but it can be done quickly.
6. Structured development
The data dictionary will define the elements in the data flow diagram
7. Object-oriented
Package:
Different forms of polymorphism:
Object-oriented design principles:
8. Connections in relational operators
full outer join
9. Huffman tree
10. Firewall
Firewall technology has experienced three stages of development: packet filtering, application proxy gateway, and state inspection technology
11. ISO IEC 9126 software quality model
12. Software testing
13. Connected graphs and strongly connected graphs
14. Minimum spanning tree
Minimum spanning tree : Among all the spanning trees of a connected network, the spanning tree with the minimum sum of the costs of each edge is called the minimum cost spanning tree of the connected network, or the minimum spanning tree for short.
15. Object-oriented analysis
16. Agile development XP
17. Viruses
The Trojan horse program is generally divided into a server (Server) and a client (Client). The server is the part that the attacker transmits to the target machine, and is used to listen on the target machine and wait for the client to connect. The client is the part used to control the target machine and is placed on the attacker's machine.
Trojan horse programs are often disguised as tool programs or games. Once users open email attachments with Trojan horse programs or download them directly from the Internet, or execute these programs, when you connect to the Internet, this program will The hacker will be notified of the user's P address and the pre-set port. After receiving the information, the hacker can use the hidden program to arbitrarily modify the user's computer settings, copy any files, spy on the data in the user's entire hard disk, etc., so as to achieve the purpose of controlling the user's computer.
Now there are many such programs, such software in foreign countries include Back Office, Netbus, etc., and such software in China include Netspy, YAI, SubSeven, Binghe, "Guangwai Girls" and so on. Sniffer is a network analysis software based on the principle of passive listening. Using this software, you can monitor the status of the network, data flow and information transmitted on the network, which is not a Trojan horse program.
18. Deadlock
19. Recursive time complexity
20. SMTP and POP3 (email protocol)
21. Compiler and Interpreter
22. RISC and CISC
23. Layers corresponding to various protocols
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24. Integration testing strategy
25. Database design
26. Bitmap
27、HTTP和HTTPS
The HTTPS protocol is a secure hypertext transfer protocol that encrypts the data to be transmitted by using SSL technology, and uses port 443 of the TCP protocol. The HTTP protocol uses clear text to transmit hypertext data, which has poor security.
28. Sequential storage of binary tree
29. Domain name process
30. Encryption algorithm
31. Distributed database
32. Software maintainability expressions
33. Huffman coding compression ratio
34. thread
35. Coupling
36. Classification of Design Patterns
37. TCP and UDP protocols
Both TCP and UDP provide port addressing function
UDP is an unreliable, connectionless protocol with no connection management capabilities, no responsibility for resending lost or erroneous data messages, and no flow control capabilities.
38. PERT diagram
39. Assembly and disassembly
Compilation is the translation of a high-level language source program into a machine language program (assembly form or machine code form). Disassembly usually cannot restore an executable file to a high-level language source code, but can only be converted into a functionally equivalent assembler program
40. Check code
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41. Encryption and decryption technology
Encryption and decryption are reciprocal, encrypted with the public key and decrypted with the private key, enabling secure communication
Encrypt with private key, decrypt with public key, and realize digital signature
42. Communication path
43. Software engineering model
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44. Characteristics of various sorts
- Direct insertion sort: stable and non-returning, suitable for basic ordered situations
- Hill sort: unstable and not homing
- Simple Selection Sort: Unstable Homing
- Heap sort: unstable homing
- Bubble Sort: Stable Homing
- Quick sort: unstable homing, the efficiency of quick sort is the lowest for basically ordered sequences, and the time complexity is the worst case
- Merge sort: stable and non-returning
45. Software project estimation
Capability Maturity Model
46. Simple Selection Sort
47. Single and double buffer
48. UML Diagram Summary
49. Computer system reliability
50. Database conflict
Naming conflict. Because the same object names different
structure conflicts. Because the attributes of the same object are different,
the attribute conflicts. Because the type and value range of the attribute are different