The 1st theme: Introduction to the design of algorithms. Evaluation of algorithms in terms of volume and time. Horner's scheme for calculating the value of polynomials

The verbal form of the algorithm

• The verbal form of the algorithm representation has a number of disadvantages. For sufficiently complex algorithms, the description becomes too cumbersome and not visual. This form of representation is usually used only at the initial stages of algorithm development.

Example to verbal form of the algorithm

• An example of a verbal form for describing the algorithm: To cross the street, you need to look to the left, make sure there is no approaching traffic, reach the middle of the street, look to the right, make sure there is no nearby traffic, continue moving across the street. In the presence of moving vehicles, you need to wait for the transport to pass.

The representation in programming languages

• An algorithm written in a programming language is called a program.

The graphic form of the representation of algorithms

• The graphic form of representation of algorithms is more visual and rigorous. The algorithm is depicted as a sequence of interconnected blocks, each of which corresponds to the execution of one or more operators. Such a graphical representation is called a flowchart of the algorithm.

To draw a flowchart following standard symbols are use

To draw a flowchart following standard symbols are use

Algorithm & Flowchart to find the sum of two numbers

The use of flowcharts makes it possible to:

• The use of flowcharts makes it possible to:
• visualize the basic constructions of the algorithm;
• focus on the structure of the algorithm rather than on the syntax of the language;
• analyze the logical structure of the algorithm;
• transform the algorithm by the method of enlargement (reduction to a single block) or detailing - splitting into a number of blocks;
• use the principle of blocks in the collective solution of a complex problem;
• carry out a quick check of the developed algorithm (at the level of the idea);
• to analyze a larger number of learning tasks.