From Big Medical Encyclopedia

ALGORITHM — the instruction (system of the rules) determining the content and operating sequence, providing problem solving of a certain class.

The term «algorithm» comes from a name of the medieval Uzbek mathematician Al-Horezmi who in 9 century formulated rules of performance of four arithmetic actions.

The algorithm belongs to number of the basic mathematical concepts and it makes exact sense. In other sciences, including and in medicine, this concept is used in a broader sense. To Algoritmizirovat any process — it means to provide creation And., performance to-rogo guarantees achievement of desirable result.

Any mathematical Algorithm shall have property of determinancy (definiteness), effectiveness and mass character. To determine the Algorithm — it means to make each instruction which is contained in it in such measure unambiguous and exact that the result of implementation of this instruction did not depend on the one who and when follows it. Under effectiveness (or an orientation) And. understand the requirement of that the algorithmic procedure applied to any task from the set class through final number of steps stopped. After such stop the required result shall be received. Understand the fact that the Algorithm shall solve not a specific objective, a class A of tasks as mass character. The description of this class of tasks communicates with this And., which cannot be torn off from this description.

Also discretization of the process determined by it (its raschlenennost on separate consecutive acts) and simplicity of the operations which are carried out continually is characteristic of the Algorithm. Any process, for to-rogo it is possible to make the Algorithm, it can be essentially automated. To develop And. solutions of a task only the specialist in that area can, to a cut this task belongs.

The developed Algorithm can be presented in the form of a formula for the solution of mathematical tasks, the scheme (graphic And.), the verbal description of rules or it is combined it is expressed these three ways.

Algorithms, according to-rymi the solution of a task comes down to arithmetic actions, are called numerical A. Chislennymi A., e.g., any formulas and schemes, sluzhagtsy for the solution of a nek-ry class of tasks are if are completely expressed by these formulas as structure of actions (multiplication, subtraction, division), and an order, in Krom they shall be carried out. In mathematics are considered also And., where the instruction of a way of actions belongs not necessarily to digital objects. Can be an example And. for the solution of a logical task — search of a way in a labyrinth. And. such orders how on each crossing of a corridor of a labyrinth it is necessary to make the decision on along what corridor to follow in order that after some number of turns to reach the set place in a labyrinth, e.g. an exit.

In biology, medicine and other natural sciences the Algorithm represents the nek-ry sequence of instructions, without assuming strict unambiguity of each instruction. So, e.g., often enter into consideration And., in which actions on nek-rum a step in this or that sense are accidental. In these cases it is possible to speak about the solution of a task in nek-rum probabilistic sense. In other cases it is possible to take result which will turn out after the nek-ry fixed number of the executed instructions for the solution of a task And.

Consideration And. in it, broader understanding, though does not guarantee obtaining identical results, but allows to transfer to other person a certain system of rules, a cut it is necessary to be guided directionally to move to the purpose or, in any case, to approach it.

Development of the Algorithm is represented reasonable where there is a need of standardization of action: e.g., during the processing of the case histories any of objectively removed curves (time-temperature charts, encephalograms, an ECG etc.) or in attempts to formalize (in this case to describe) process of diagnosis (see. Diagnosis , diagnosis ).

Bibliography: Yzerman M. A., etc. Logic, Automatic machines, Algorithms, M., 1963; Lyapunov A. A. and Shestopal G. A. About the algorithmic description of management processes, in book: Matemat. education, under the editorship of Ya. S. Dubnov, etc., century 2, page 81, M., 1957; Trakhtenbrot B. A. Algorithms and machine problem solving, M., 1957.

O. I. Aven.