Postgraduate entrance exam 408 includes data structure, computer network, computer composition principle and operating system four subjects, each of which is the content that programmers should focus on understanding and mastering.
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Analysis is my own writing, if there are questions or mistakes please comment to inform, hope to point a big praise 💗
The data structure
Post-ordered ergodic trees belong to the following ergodic category ___ (Beijing University of Posts and Telecommunications 2013)
A. Depth-first traversal B. Random traversal C. Breadth-first traversal D. In the sequence traversalCopy the codeAnswer and analysis
Answer: A,
🔊 both front, middle and rear order traversal belong to depth-first traversal. The order of rear order traversal is left and right roots, traversing the left child first, then the right child, and finally the root node.
Computer network
The main functions of the network adapter are ___ (Ocean University of China)
A. Functions of the physical layer and network layer B. Functions of the network layer and application layer C. Functions of the physical layer and data link layer D. Functions of the network layer and presentation layerCopy the codeAnswer and analysis
Answer: C
🔊 Devices at the data link layer use the MAC address of the network adapter. MAC is also called media access control. This is also the work of the network adapter, so the network adapter also works at the physical layer.
Computer composition principle
The minimum unit time in computer is ___ (Nanjing University of Aeronautics and Astronautics, 2016)
A. Clock cycle B. Instruction cycle C. CPU cycle D. Execution cycleCopy the codeAnswer and analysis
Answer: A,
🔊 Clock cycle is the reciprocal of clock frequency. It is the most basic and smallest unit of time in A computer.
The CPU cycle is also the machine cycle. The execution process of an instruction in a computer is usually divided into several stages. Each stage completes a basic operation, and the time required to complete a basic operation is called the machine cycle. In general, a machine cycle consists of several clock cycles.
Therefore, the instruction cycle consists of several machine cycles and is the sum of the time from the value to the completion of execution.
The operating system
Among the components of a process, the part of the process that cannot be modified during operation is ___ (Henan University 2003)
A. private program segment B. shared program segment C. Data set D. process control blockCopy the codeAnswer and analysis
Answer: B
🔊 sharing program certainly cannot modify ah, modify other procedures how to do 😂