Small knowledge, big challenge! This article is participating in the creation activity of “Essential Tips for Programmers”.

🌴 Data structure

The time complexity of an algorithm is O(n2), indicating that ___

A. The problem size is n^2 B. The execution time is equal to n^2 C. The execution time is proportional to n^2 D. The size of the problem is proportional to n^2Copy the code

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Answer: C

📢 time complexity is O (n2), the execution time of the algorithm of T (n) < = c n2T \ n (n) < = c ^ 2 T (n) < = c n2 (c for proportionality constant), T (n) = O (n2) T (n) = O (n ^ 2) T (n) = O (n2).

The time complexity T(n) is a function of the problem size n, which is still n rather than N2.

🌳 Computer network

In the following network topology, the network with a certain centralized control function is ___ (Central University of Finance and Economics 2006)

A. Bus network B. Star network C. Ring network D. Fully connected networkCopy the code

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Answer: B

📢 Several common topologies are shown in the figure. In the star topology, communication between end users must pass through the central station for centralized control.

🌵 Operating system

Of the following options, ___ is not the main concern of the operating system (Zhejiang University, 2003)

A. Management of bare computer B. Design and provide interfaces between user programs and computer hardware systems. Manage computer system resources D. Compiler for a high-level programming languageCopy the code

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Answer: D

The 📢 compiler is the software on top of the operating system, and the other options are the services and functions that the operating system needs to provide.

Operating System (OS) is a program set that controls and manages the hardware and software resources of the entire computer System, reasonably organizes and schedules the work of the computer and the allocation of resources, and thus provides convenient interfaces and environments for users and other software.

🌲 Computer composition principle

The 8-bit complement code of decimal value +0.3125 is ___ (Xidian University, 2007)

A. 28H B. 58H C. 8H D. 8HCopy the code

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Answer: A,

📢 work out the source code, the positive source code is the same as the complement code, so:


0.3125 = 0.25 + 0.0625 0.3125 = ( 0010   0100 ) 2 = 28 H The highest bit is the sign bit, and the decimal point is hidden behind the sign bit 0.3125 = 0.25+0.0625\0.3125 = (0010\ 0100)_2 = 28H \\ The highest bit is the sign bit, and the decimal point is hidden after the sign bit

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)