This is the fourth day of my participation in the November Gwen Challenge. Check out the details: The last Gwen Challenge 2021

🐻 Data structure

A total of 1 million people participate in the competition. The top 20 winners are selected as winners. The winners’ results are output in descending order of score. (Jilin University, 2017)

A. Quicksort B. Heap sort C. Merge sort D. Bubble sortCopy the code

parsing

Answer: B

🐲 First of all, since the topic only needs the top 20 as winners, the sorting algorithm of the top few can be displayed in the sorting process without completing the sorting process, including heap sorting, bubble sorting and selection sorting.

For very large numbers of sorts, heap sort is more suitable than bubble sort and selection sort because of its better average time complexity.

Although quicksort and merge sort are suitable for large numbers of sorts, neither of them can guarantee to determine the final position of a sorted element in a round of sorting, so they are not considered.

🐼 Computer network

In the TCP/IP architecture, the protocol that provides services for ICMP directly is ___ (Xidian University 2017)

A. PPP
B. IP
C. UDP
D. TCP
Copy the code

parsing

Answer: B

🐲 Internet Control Message Protocol (ICMP) Network Control Message Protocol. As a subprotocol of TCP/IP, it is used to transfer control messages between IP hosts and routers.

ICMP uses the basic support of IP as if it were a higher level protocol. However, ICMP is actually a part of IP and must be implemented by each IP module.

  • Transport layer: TCP, UDP
  • Application layer: FTP, SMTP, HTTP
  • Network layer: IP, ARP, DHCP, ICMP

🐨 Operating system

The main features of the primitive are ___ (Xi ‘an University of Technology 2001)

A. Indivisibility B. non-reproducibility C. non-masking D. inaccessibleCopy the code

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Answer: A,

The 🐲 primitive refers to a program composed of several machine instructions to perform a specific function. This procedure is indivisible during its execution. A. indivisible B. indivisible C. indivisible D. indivisible

Some operations called by a process, such as queue operations, operations on semaphores, checking startup peripherals, etc., cannot be interrupted once executed, otherwise there will be an operation error, causing chaos in the system, so these operations are implemented using primitives.

Primitives are an integral part of the operating system core (consisting not of processes but of a set of program modules) and reside in memory, usually executed in a tube state. Once a primitive is executed, it is executed continuously without interruption.

🐻❄️ Computer composition principle

Direct addressing refers to ___ (Jiangsu University 2016)

A. The operand address B is given directly in the instruction. The operand C is given directly in the instruction. The operand D is given in the middle of the instruction. The address of the operand is given in the middle of the instructionCopy the code

parsing

Answer: A,

🐲 direct addressing is a basic addressing method, characterized by: in the address field of the instruction format directly indicate the memory address of the operand.

The address of the operand is given directly without any transformation. A. direct b. direct C. direct D. direct

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)