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I would like to know what algorithms are. I program in C, study C++ and Python. In all the online courses I’ve taken, I’ve heard of such an algorithm, but I don’t know what it is.
2 answers
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An algorithm is nothing more than a recipe (like movie script, cake recipe) that shows step by step the procedures necessary for solving a task. He doesn’t answer the question what to do?, but yes how to do. It is a finite and defined sequence of instructions that must be followed to solve a problem or perform a task.
Switching
What you do in C, C++ and Python (Languages you know) and in any other language is to implement an algorithm, even when it is only one hello world, one for printing 0 to 10.
Example of a lamp exchange algorithm:
Início
Verifica se o interruptor está desligado;
Procura uma lâmpada nova;
Pega uma escada;
Leva a escada até o local;
Posiciona a escada;
Sobe os degraus;
Para na altura apropriada;
Retira a lâmpada queimada;
Coloca a lâmpada nova;
Desce da escada;
Aciona o interruptor;
Se a lâmpada não acender, então:
Retira a lâmpada queimada;
Coloca outra lâmpada nova
Senão
Tarefa terminada;
Joga a lâmpada queimada no lixo;
Guarda a escada;
Fim
Flowchart of an algorithm:
Classifications of Algorithms by Implementations:
Recursive or iterative - a recursive algorithm has the characteristic of invoking itself repeatedly until a certain condition is satisfied and it is terminated.
Logical - an algorithm can be seen as a controlled logical deduction.
Serial or parallel - algorithms are generally assumed to be executed by instructing to instruction individually, such as an execution list, which constitutes a serial algorithm.
Deterministic or non-deterministic - deterministic algorithms solve the problem with an exact decision at each step while non-deterministic algorithms solve the problem by deducing the best steps through estimates in the form of heuristics.
Exact or approximate - while some algorithms find an exact answer, approximation algorithms look for an answer close to the true solution, either through deterministic or random strategy.
Classification of Algorithms by paradigm:
Division and conquest - division and conquest algorithms repeatedly reduce the problem into sub-problems, usually recursively, until the sub-problem is small enough to be solved.
Dynamic programming - dynamic programming can be used to avoid the previously solved solution re-calculation.
Greedy algorithm - a greedy algorithm is similar to dynamic programming, but differs in that the solutions of the sub-problems do not need to be known at every step, a greedy choice can be made at every moment with what hitherto seems to be most suitable.
Linear programming - Solving a problem through linear programming involves maximizing / minimizing the inputs of a set of linear inequalities.
Downsizing - reduction solves the problem by transforming it into another problem. It is also called transformation and conquest.
Search and enumeration - various problems can be modeled through graphs. A graph scanning algorithm can be used to walk through the structure and return useful information for solving the problem.
Heuristic and probabilistic paradigm - probabilistic algorithms make random choices. Genetic algorithms try to find the solution through cycles of evolutionary mutations between generations of steps, tending to the exact solution of the problem.
Sources:
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It is a finite sequence of rules, reasoning or operations that, applied to a finite number of data, allows solving similar classes of problems. Practically summing up is like a cake recipe, will have to perform step by step to solve a problem. Usually at the beginning of computer studies, people choose to study algorithms with the English language in Visualg. (Because the syntax is in Portuguese and seems to be easier)
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It was huge. But I liked it. Let me see if I understand: the algorithm is what shows the steps for solving a task. For example, when creating a while loop to count from 1 to 10, I made an algorithm that shows all the steps to make the program go up to 10 and stop.
– Mateus Souza
you have implemented an algorithm that prints from 0 to 10 and finishes.
– Ricardo
Do you know English? it is a pseudo-language used to teach algorithm structuring.
– Ricardo
The same way for Hello World, right?
– Mateus Souza
Yes. I’ve heard of Portugol. I’ve seen it on Wikipedia.
– Mateus Souza
My opinion: It is better to learn how to create algorithms directly in the language
Cwhy you learn to create algorithms and at the same time a real programming language.– Ricardo