This article has participated in the “Digitalstar Project” and won a creative gift package to challenge the creative incentive money.
408 contains four subjects, including a variety of basic computer theory, even if you do not take the postgraduate entrance examination, it is good to know some basic knowledge. Welcome to me and my column 🔥
Borrow a big man’s words: for a programmer, the basic knowledge of the computer is internal power, is our professional accomplishment, only deep internal power can walk the river’s lake less.
Programmers can go far, can write high-quality code, can quickly find the bottleneck of the system, can quickly find the core functions of the system, and our professional literacy must be related. Only if you know the basics well enough, can you be truly proficient in your work and solve problems more efficiently and gracefully.
🙈 Data structure
Let hash table length M=14, hash function H(Key)= Key Mod 11. There are 4 elements in the table, and their keywords are 4, 27, 61, 84 respectively. If the conflict is handled with secondary detection and hash, the address of the node whose keyword is 49 is. (University of Chinese Academy of Sciences, 2018)
A.9
B.8
C.3
D.2
Copy the codeparsing
Answer: A,
🤡 Simple calculation:
For quadratic rehash, d=1, -1, 4, -4, 8, -8.
H(49)= 5,456 is occupied, so we can only add 4 to 9, which is choice A.
🐵 Computer network
When assigning IP addresses to hosts on the network, the following addresses are incorrect. (Chongqing University in 2005)
A.29.9.255.254 B. 129.21.255.109 C. 195.5.91.254 D. 220.250.2.255Copy the codeparsing
Answer: D
The address in 🤡 D is a class C address. 255 is the host NUMBER, but 255 cannot be the host number. All host numbers are 1, indicating the broadcast address of the local network.
Some IP addresses have special functions and do not need to be used as host IP addresses:
- All 0 host ids indicate the network itself.
- Host ids all 1 indicate the broadcast address of the local network, also known as the direct broadcast address.
- X.X.X is reserved as the loopback address. This address represents any host itself. IP datagrams whose destination address is a loopback address will never appear on any network.
- 0.0.0.0 indicates the local host on the local network.
- 255.255.255.255 is a broadcast address on the entire TCP/IP network, which is also called a restricted broadcast address. In practice, because the router isolates the broadcast domain, it is equivalent to the broadcast address of the local network.
🙊 Operating system
Computer systems using SPOOLing technology, peripheral computers required. (Lanzhou University, 2004)
A. A B. More than one C. At least one D. 0Copy the codeparsing
Answer: D
The 🤡 SPOOLing technology requires the use of disk space (input/output Wells) and memory space (input/output buffers) without peripheral computer support.
Turning a stand-alone printer into one that can be shared by multiple users is a typical example of SPOOLing technology. Instead of actually assigning the printer to the user process, the system first applies for a free disk block in the output well and feeds the printed data into it. The request print form is then requested and filled out for the user, and the form is attached to the request print queue. If the printer is idle, the output program fetches the table first from the request print queue, passes the data to be printed from the output well to the memory buffer, and prints again until the print queue is empty.
🙉 Computer composition principle
A disk running at 7200 RPM with 160 sectors per track and 512 bytes per sector would ideally have a data transfer rate of.
A. 7200×160KB/s b. 7200KB/s c. 9600KB/s d. 19200KB/sCopy the codeparsing
Answer: C
🤡 Simple calculation
The exercises come from @Wangdao Weibo
The analysis is written by myself, if there are any questions or mistakes, please comment.
I am Mancuoj, welcome to pay attention to me and my computer entrance examination column (≧∇ Blue)