What are the main algorithms of the operating system?

Know. Computer programs.

What are the three basic structures?

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The three basic structures of a computer program are: sequential structure, branching structure, and cyclic structure.

1. Sequential structure:

The sequential structure is that a program runs from the first line to the last, that is, the program runs from beginning to end.

2. Branch structure:

The execution of the branching structure is based on certain conditions, rather than strictly following the physical order in which the statements appear. The key to the programming method of branching structure is to construct appropriate branching conditions and analyze the program flow, and select appropriate branching statements according to different program flows. Branching structures are suitable for those with logical or.

Calculation of conditional judgment such as relationship comparison, when designing this kind of program, it is necessary to draw the program flow chart first.

Then write out the source program according to the program flow.

In doing so, the kernel sequestration separates the programming analysis from the language, making the problem simple and easy to understand.

3. Circular structure:

It is generally used to repeat a certain segment and need to be repeated repeatedly.

Common features: All three structures have only one entrance and one exit.

There is no such thing as an endless loop within any of the three structures. Change annihilation.

There are three basic logical structures of algorithms: sequential structure, conditional branching structure, and loop structure.

What the three basic structures have in common:

1) There is only one entrance and exit.

2) Each part of the structure has a chance to be executed, that is to say, for each box, there should be a path from the entrance to the exit through it, as shown in the figure a, there is no path from the entrance to the exit through it, that is, the algorithm structure does not meet the requirements.

3) There is no dead loop in the structure, that is, there is no end to the loop.

Scheduling algorithms. 1.First-come, first-served (FCFS): Schedules jobs in the order in which they are scheduled.

The simplest scheduling algorithm, which is not good for short jobs (longer average turnaround time), non-preemptive.

Processing: (1) Assign the CPU to execute according to the order of job submission;

2) The current job occupies the CPU until the execution is completed or blocked (such as applying for IO) to give up the CPU;

3) After the job is woken up (if the IO execution is completed), the execution is not resumed immediately, and the execution can be resumed only after the current job has given up the CPU.

2.Short Job Priority (SJF): Jobs are scheduled in order of length, and short jobs are prioritized.

Sequential structure. Branching structure. Circular structure.

The operating system is not an algorithm. An algorithm is defined as a set of instructions that have a canonical input to obtain the required output within a certain limited time. By definition, it is two different concepts from the operating system, of course, the operating system itself is executed by many different algorithms, such as disk scheduling algorithms, process scheduling algorithms, and so on.

Operating system (OS) is a computer program that manages and controls computer hardware and software resources, and is the most basic system software that runs directly on "bare metal", and any other software must be supported by the operating system to run.

The operating system is the interface between the user and the computer, as well as the interface between the computer hardware and other software. The functions of the operating system include managing the hardware, software and data resources of the computer system, controlling the operation of programs, improving the human-computer interface, providing support for other application software, maximizing the use of all resources of the computer system, providing various forms of user interface, enabling users to have a good working environment, and providing necessary services and corresponding interfaces for the development of other software. In fact, the user does not have to touch the operating system, which manages the computer hardware resources and allocates resources according to the resource requests of the application, such as:

Divide CPU time, open up memory space, call printers, etc.

How to put it, the operating system should be a combination of many algorithms together!

Personally, I think that the algorithms mentioned in the course of operating systems are generally implemented in C language or assembly language.

1. The following are a few concepts about algorithms found on the Internet, and I personally prefer the first one:

1. An algorithm is a well-defined set of rules used to solve a problem in a finite step. In layman's terms, it is the process of computer problem solving. In this process, whether it is forming a solution idea or writing a program, it is implementing some kind of algorithm.

The former is an algorithm for inference implementation, and the latter is an algorithm for operational implementation.

2. The term "algorithm" first came from the influential work "Algebraic Dialogues" by the Persian mathematician Bial Khovarisson in the 9th century AD. of the 20th century.

The British mathematician Turing developed the famous Turing argument and abstracted a machine, which we call the Turing machine. Turing's ideas played an important role in the development of algorithms.

An algorithm is the essence of how computers process information, because a computer program is essentially an algorithm that tells a computer the exact steps to take to perform a given task, such as calculating an employee's salary or printing a student's transcript.

In general, while the algorithm is processing information, the data is read from the input device, written to the output device, and possibly saved for later use.

3. Algorithm refers to the accurate and complete description of completing a task. That is to say, given an initial state or input data, a computer program can perform a finite number of operations to obtain the required or desired termination state or output data. Algorithms can be implemented not only with computer programs, but also with artificial neural networks, circuits, or mechanical devices.

Computer operating system (computer system software).

The operating system (OS) is the system software responsible for supporting the application running environment and the user operating environment in the electronic computer system, and it is also the core and cornerstone of the computer system. Its responsibilities often include direct oversight of hardware, management of various computing resources (e.g., memory, processor time, etc.), and provision of application-oriented services such as job management.

An operating system is a collection of system software (or programs) that facilitates users, manages, and controls the software and hardware resources of a computer. From the user's point of view, the operating system can be seen as an extension of the computer hardware; From the perspective of human-computer interaction, the operating system is the interface between the user and the machine; From the perspective of the system structure of the computer, the operating system is a collection of programs with a hierarchical and modular structure, which belongs to the ordered hierarchical method and is the orderly hierarchical call of disordered modules. The design of the operating system embodies a combination of computer technology and management technology.

The operating system is software, and it is the system software. Its role in the computer system can be roughly experienced from two aspects: internally, the operating system manages various resources of the computer system and expands the functions of the hardware; Externally, the operating system provides a good human-machine interface, which is convenient for users to use the computer.

It has the status of connecting the past and the next in the entire computer system.

Computer system refers to the computer hardware and software and network system used for database management. Database systems require a large capacity of primary memory to store and run operating systems, database management system programs, applications, databases, directories, system buffers, etc., while secondary memory requires a large capacity of direct access devices. In addition, the system should have strong network capabilities.

An operating system is a computer program that manages and controls computer hardware and software resources, and a program is a collection of several algorithms.

What do you mean? You didn't express this question clearly!