Methods of describing algorithms and types of algorithms

With the word "algorithm" many people came across. After all, the life of people is closely connected with him. What it is? What are the ways of describing algorithms, types of algorithms? What are they needed for? This article will help in all this to understand and put everything in its place.

Algorithm: concept, types, ways of description

The term itself means an understandable and precise sequence of simple steps that the performer must go through to solve the task assigned to him. The very word "algorithm" takes its origin from the name of the famous oriental mathematician Al-Khorezmi. It was he who formulated all the rules by which arithmetic operations are performed. At the very beginning, this concept was understood only by rules relating to the main four arithmetic operations performed on numbers. And then the concept was used to indicate the sequence of steps leading to the solution of the problem. In the computational process, the data are the objects to which the algorithm is applied. At the decision of a problem of calculation the initial data are transformed to result.

The algorithm development process is very creative, despite its simplicity. If a man can compose it, then the technique is capable of performing. And today it is not only a computer, but also phones, tablets, terminals and even washing machines with coffee makers.

On requests on the Internet you can find a lot of valuable information, but it still needs to be collected together. Therefore, all the essentials are indicated here.

What basic properties does the algorithm have?

1. Certainness. This property is also called determinism. It involves obtaining a result of calculations, which is unambiguous when specifying the initial data for calculations. This property gives the process a mechanical character. Do not need additional information and instructions about the task. There should be nothing arbitrary.

2. The mass. This property assumes that the algorithm should be suitable for solving a set of problems of the same type. The initial information in this case can be selected from some area, called the field of application.

3. Effectiveness is a property that indicates the availability of the initial information, for which, according to a given sequence of actions, the process must pass a finite number of steps, and then stop, producing the necessary result.

4. Discreteness is when the computational process is divided into stages. And the possibility of their implementation does not cause any doubt. Here, each subsequent action is performed only if the previous one is completely finished.

Methods of describing algorithms that everyone understands

Algorithms should be formalized according to certain rules using specific means. The main ways of describing algorithms: with the help of words, formula-verbal, algorithmic, graphical and software.

A verbal form is a record in the natural human language. It was much less common, because it is too verbose. And yet it lacks visibility. The description of words is not strictly formalizable, and some of the prescriptions can be interpreted ambiguously.

Formally verbal form is a little more convenient. Here mathematical formulas are added to the words, which can both help and, vice versa, confuse the person when reading. Other ways of describing algorithms are much more convenient.

Methods for describing algorithms for programmers

The algorithmic method of recording is based on pseudocode. This is a code that is similar in structure to the programming language, but commands are specified in natural language, and mathematical expressions are also present. Pseudocode is a semi-formalized language. This method is much more understandable, especially for programmers.

The methods for describing the algorithms described above were completely formalized, after which the program form of the record was born. Here one of the many programming languages is used, on which the same sequence of steps for execution is written. The computer reads them in turn and executes the specified instructions, which ultimately leads to the final result.

The most popular way of describing

The graphical method of describing algorithms has received the greatest popularity because of its clarity. It is also called a block-diagram method. What is a block diagram? This is a graphical representation of the algorithm scheme. Each step of the data processing process is represented as a geometric figure, called a block. Each block has its own configuration, which depends on the type of operation being performed. The name and the list of symbols, sizes and forms, as well as the functions to be displayed, are defined by the standards. If we take all the basic methods of describing algorithms, then this is the most obvious.

Calculation processes

Methods of describing algorithms using flowcharts imply three main types of computation processes: linear, branching and cyclic.

Linear is a process where each step in the solution of a problem is performed in order.

A branching is a calculation process in which the choice of the direction of motion depends on the initial or intermediate information, as well as on the results of checking the logical conditions.

A cyclic algorithm contains one or more one cycle, that is, a computation section that is repeated many times. Cycles can be with a predetermined number of repetitions and with an undefined number. Depending on the observance of any condition, the number of these repetitions is also determined. And the condition can be checked at the very beginning of the cycle or at its end.

The methods for describing the algorithms are clear, but there are also rules that are presented to them.

Rules for creating algorithms

First, when designing an algorithm, you need to specify many objects to work with. The formalized representation of such objects is the data. The algorithm begins to work with a set of data called input, converting them into a result-output data. Any method of describing algorithms can be used. The properties of algorithms must be observed.

The second rule is that in order for the algorithm to work, it needs memory. It contains the input data, intermediate and output. Memory itself is discrete, that is, it consists of separate sections - cells. That cell that has a name is called a variable.

The third rule is discreteness. The whole algorithm must be built from individual operations, the number of which must necessarily be finite.

It should be noted that there is such a thing as an auxiliary algorithm that is developed in advance, and then applied in the algorithmization of another task. It can also be called an auxiliary procedure.

Algorithm, concept, properties, methods of description - without all this in the field of computer science anywhere. This is the base on which all computer science is held.