Primeiro Algoritmo - Curso de Algoritmos #02 - Gustavo Guanabara

♫ ♫ Opening Music Hello welcome its second class of your algorithm course. My name is Gustavo Guanabara, I'm your teacher. And now we are going to continue our algorithm study last lesson we saw some logic problems we got to that which serves an algorithm, which is the function of an algorithm for our lives and now we're going to focus on computational algorithms.

That is exactly what we will study in this course of programming logic or algorithms. So as I just said our subject, our main focus will be computational algorithms and there you will ask me, hey Guanabara what is the difference between algorithm and computational algorithm? Well, when I say algorithm is all kind of routine you perform and can be in their day to day as I said go to work, go to school, brushing teeth, bathing, lunch.

everything that you do and that is routine algorithms can be considered. computational algorithms, the concept is the same only the execution of focus is a bit different Go to a concept that I created myself and you will understand easily the definition that I created computer algorithms is simple. "Algorithms are steps to be followed by a processor module and their users, when executed in the correct order, they can perform a particular task.

" And we have highlighted here four terms: Processor module is all that can perform processing. And when I say everything that can perform processing, I say all the same It can be a laptop computer, can be a big computer like this that is recording the classes, It may be this little one, It can be a tablet, It can be a smartphone, can even be the camera that is recording me at that time, she run a software. Processor module today is all that can be programmable.

The second term is highlighted in green there is "users". User is you, you who are using you when developing their algorithms will want others to use this program these other people are users. The last two terms are "hold" particular "task".

And how to perform a task understands how to solve a problem, any need that your user is having and that requires the processor module to solve this problem You get the idea? So understand the following: computer algorithms are executed routines for a processor, or a set, or a computer or a smartphone, or whatever and this is what we learn during this course, how to create computer algorithms. When I speak of computational algorithms, I'm talking about everything.

Initially you may think of those old management systems, those programs who managed store, pharmacy, supermarket, inventory management control. These are all algorithms, yes. They are still developed They are very important pro IT market, pro market technology as a whole, but there are other types of algorithms that you have on your day-to-day, for example, when you access the Home Bank.

Access your bank account, view balances, make transfers today, They are all controlled by algorithms. And this happens even when you access ATM, or even when you enter a queue and will the actual box, so he can make a transfer or a deposit. Every procedure that the employee will do, It is through computer systems, then algorithmically.

Also another way, when you access social networks, access your Facebook, Twitter, Instagram, Bind Rest, whatever it is, all these are computer algorithms that are running on high-performance servers. When you watch video. You're at that moment watching this video, watch videos, Algorithms are compression algorithms, display algorithms, they are all very important nowadays And even when you play, you can play on your computer, or even play on portable, use in portable programs, all you are doing is using computational algorithms.

And then you can ask me: "More, Guanabara, how these computational algorithms are created? How do I start? What is the first step I have to give to create these computational algorithms?

" And I will answer you: All computational algorithm begins with the creation of Logic Programming. Programming Logic, is in your head. You still never programmed Certainly you will learn to program developing logical reasoning, by programming logic.

In the first classes is what we will work more How to build a good logic. After building your logic You will start to write this logic in a programming language any. In my case here, I gave the example of java.

But it can be PHP, can be Visual Basic, C # can be any programming language. This programming language It will be used to create a complete system! What is the application, or software that your users will use.

So the whole system is born so. He was born on the head of a system analyst and a programmer. A development team.

This logic programming Of the head of them, and is structured in a programming language. That will be used to create a complete system. To structure the logic programming we have some old tools already on the market, and that are used today.

Let us understand each. To represent the programming logic we can use various tools The best known among them are: Flowchart representing the logic through an information flow following from one point to another, if you look in the right corner of the screen, including the logo we created in Algorithms for Video course, is part of a flowchart There is another diagram which is very famous, that is Shneiderman diagram Nassi also known as Chapin diagram where you will represent the logic of your program through blocks However, these two methods that are appearing on your screen are very old And it is almost no longer used, or in the classroom. What we use today is the Pseudo or Portugol Pseudo is the logic of your program written in their native language Which in our case, as the Portuguese, was baptized as Portugol So, so, even if there are several development techniques such as Flowchart and Chapin We will focus on our course development through Portugol.

And please do not confuse Portugol is not a programming language Portugol is a way to represent their programming logic Before moving to a programming language So basically you will learn in this course: The write Portugol and with this in Portugol you will be able to convert that your logic For any programming language you learn. In our case here we will have course PHP, Java course more forward in the course of the project video, but the most important for you to learn PHP There are many people asking the channel: "I want a course in Java . .

. I want a course in PHP . .

. " It does not help me create a Java course and PHP if you do not know algorithm. Then, the construction of programming logic The construction of a good pseudocode Building codes Portugol It is very important for an IT professional So this is a first step that you have to have Before you start developing anything in your life And if you're an old programmer who learned to program a long time ago as I learned You probably learned in Portugol and Flowchart And he did it on paper The teacher showed the Portugol under And you never saw it working.

You had to believe what the teacher was saying. You had to believe it would work. Today, we have several tools that assist in learning logic programming and algorithms.

I will present to you now What is the tool that we will use. The application that we will use It is the Visualg Visualg is a compression between two terms: Algorithm Viewer The Visualg is a sensational tool well structured and very important for technology learning it was created by a teacher named Claudio Morgado and several other teachers in Brazil supported the project I am one of the teachers who support the project from the beginning I like it, I wanted to personally congratulate here Professor Claudio Morgado He owns a company called "Computer Support" And he created this tool in order to help their students learn algorithm So he used that to his students, I use with my students And now, I I am your teacher I'm using you, for you to learn algorithm. The Visualg is completely free He was registered as public domain and you can download at: www.

cursoemvideo. com accessing the area of ​​Algorithms course You will be able to download your package In this package you will have: Some exercises. You will have to download Visualg You will get the handouts that we will use during the percursso this course.

So, the algorithm learning needs much of your effort. You need a lot of practice. So the first thing you have to do is download the package, www.

cursoemvideo. com there accesses the algorithms courses, the courses area and you will have access to the package you simply enter your email there, for you to be registered in our system and the next time you access the site, this download will be fully released to you. So what I will do now is open the VisuAlg on my computer and show you how the tool.

So this is the face of VisuAlg. When you enter it, it can come up with a code or may appear to empty Appearing empty, you simply enter an exclamation mark (! ) and press "ctrl + space" This is the basic structure of an algorithm according to the sight VisuAlg Here it will create an unnamed Algorithm I'll call him first be sure to keep the quotation marks ( "") and we have two well-defined areas here Area variables (var) and body algorithm.

starting at "start" and ends with "fimalgoritimo" This screen where I typed my code It is what agent calls code screen Below we have the representation of the computer's memory its variables and scope. Do not worry about these terms because in a moment I will now explain to you what a variable, which is computer memory. In the right corner we have the terminal screen which will show all data outputs.

On top we have a menu option with several options in menu and then down a toolbar with the radio buttons most commonly used on the top menu. So you see that the VisuAlg interface is very simple it consists of a few simple areas code area the memory area below the terminal and the top bar apena is what the VisuALg is, but it is an important tool for you to learn how to create algorithms in Portugol And we'll start creating our first program and if you were my student HTML5 course You know of the "Hello World" curse, but if you come here only in the course of algorithm I'll tell you. A legend when you'll learn something in technology particularly in the programming language the first thing you have to do It is to create a program to write "Hello World" on the screen.

According to this curse, if you do not you will never learn a certain technology So if the algorithm is so important for you to know to program in PHP, Java or whatever it is, if you do the "Hello World Now you may not learn any of this I do not know if that's true, but you will risk? So our mission now is to write on the screen "Hello World" and for that you'll need to know the output command VisuAlg First output command you will learn is the "Type" The command "Write" is explanatory high, he writes something So if I want to write anything on the screen I just put Type ( "Anything") The use of quotation marks ( "") within the algorithms is very important all that is in quotation marks ( "") is considered a message, it is considered a string. So in our case as we want to write "Hello World" we have to use the "Type" with brackets and quotation marks Hello World ( "Hello World") Let's see if this works.

So we're back here and between the beginning and the end of the algorithm put the command "Write" Brackets and quotation marks ("Hello World") In my case here I'm not using accents in "hello" because of compatibility issues between terminal, keyboard and all. But you can use accent here It just may not show up well on your screen So this is our first command "Write (" Hello, World! ")" Theoretically, he should write on the screen "Hello, World!

" To run your program, there are three ways Just you click up here in the "algorithm", "Run" Faster, you can press the "F9" key on your keyboard And the third way is to click on this button here, which is the "Run" button In my case here, I will choose the third option and click the button A black screen will appear And he wrote on the "Hello, World! " And he informed me "End of execution. " And finally "Close this window to return to Visualg.

" You can close this window by clicking the "X" or by pressing the "ESC" key on your keyboard After the implementation of the program, you see here on the terminal screen you had the beginning of execution He wrote "Hello, World" on the screen, and the end of the run And voila, you are now already free of the curse One of the things my students sometimes say to me is: "More Guanabara it is very ugly! " It really is ugly, more you look, you are the first steps to be able to learn to make beautiful things And make no mistake, make beautiful things inside the T. I.

area it is nothing easy not! You have to have a knowledge and Design, You have to have a knowledge of tools to create beautiful images To be able to create beautiful things You do not want your first steps are wonderful When you're a kid, your first steps are all wobbly, you fall down, you cry, You get hurt, you're not a child who gets up and runs away So when you will learn to make algorithm, you will not learn how to make beautiful algorithms We will start by creating really ugly things, but practical And we'll gradually evolving in this thing to create an application So do not focus now the time to create beautiful applications to create beautiful experiences, to create wonderful experiences. You are learning!

And I'll celebrate that his apprenticeship with another message, which is the "I got rid of the curse. " Let's return to VisuAlg: So if I want to write another message, just I, below, use again "Write" "( 'I got rid of the curse'). " Let's run again: And you will see that the two messages appeared next to each other to: "Hello, World!

" And "I got rid of the curse! " one beside the other. And then you can ask me, "Oh, but wait a minute I put two 'Type',!

. It is to write one in line, right? " No.

Not really. The Write command causes messages to be written next to each other. There is a second command that, in addition to writing message jumps down line.

Let's see what it: Then we previously learned that there is a write command and we can put anything in parentheses and quotation marks. The other output control that I will show you is the Escreval many calls "Escreval" but I, here I will try to always call "Type L". "Escreval" is as follows: this "L" line means So it is, "Write and jump the line" His syntax is exactly the same: you put in parentheses and quotation marks, anything So in my case here, if I replace the Type for a Escreval, he will write and line jump.

Let's see if this works. So let's replace O here: Instead of writing "Hello, World! ", I'll put him write and jump down line.

Then he will write, skip to the bottom line and write "Hello, World! " Soon afterwards he will write "I got rid of the curse! " Running your code, you will see: "Hello, World!

" He jumped to the bottom line and wrote "I got rid of the curse! " See how simple is it? So we have two commands to write things on the screen: the Type and Escreval.

If you are careful, or if you're like me, you have OCD, you will see that it has an area of ​​your algorithm that does not write anything, which is an area called Var and for that, you have to learn what variables. Looking here in my code I have, from the beginning and fimalgoritmo, I have the commands, and these commands can be written in this area. But the Var area're empty.

Let's see now what are variables. Every teacher explains technology variable in the same way, and I will not be different because different this is a great explanation. Variables are spaces.

As this image is showing there is a closet full of holes. This "cabinet" is the basic representation of the computer's memory. Computer memory is like this: it's like a place full of empty spaces.

These spaces can be filled with values. So let's imagine the following situation: we have this closet full of empty space, and in some places this closet I put labels, small labels. We put a, for example: in this first area, we will put a label stating the following: "here we'll just put a ball" which is a kind of toy.

You can also, in another area, create another label as, for example, that down there we will put: "Here one can put shoe" which is a type of footwear. So if I have a ball and want to keep that closet, I'll put it in a specific place, which is to ball, which is a type of toy. Similarly, if I have a pair of shoes, I'll put in the shoe area, which is a footwear.

If you notice, I put the ball in the top left corner, if I, by chance, another ball and want to put in the same space, just looking, you realize that will not fit another ball there, and variables is exactly that: when I put a value on a single variable, I can not put other value then, in my case here, if I want to put a colored ball in place of this classic soccer ball, I'll have to take the soccer ball that is already there, and put the other ball. With variable is the same: if you already have a variable with a value, to put another value, you have to take the first. And so we're creating our closet, placing specific labels as, for example, a scuff label which is a type of shoes and a doll tag, which is a kind of toy.

If you notice well, these our labels follow the same pattern. She has, first, the object name that will be saved, then the type to which this object belongs. So we basically have two types that image you are seeing: the toy and the type footwear.

I have a shoe that is shoes, and a slipper, which is footwear. I have a doll, it's toy, and a ball, which is toy. In that area of ​​variables that we saw earlier, we always have to put the handle, colon and type.

Then you look in the right corner and you have: ball, which is the handle and toy that is the type. Let's understand what for serving the handle. As the name implies, identifiers identify certain variables.

There are six rules for naming identifiers within the VisuAlg, and you have to know them all. Time to give a name to something, eg ball. Ball is an identifier, including a valid identifier within the six rules.

We know each of them: The first rule is: the identifier must start with a letter. Always starting with a letter The second rule is: the next characters can be letters or numbers. then the identifier name, first comes the letter, then soon may come more letters or even numbers.

The third rule is: an identifier, you can not use any symbol, except the underline symbol or underlined. So you can not use dollar sign '$' at sign '@' hash '#' percentage '%' asterisk '*' parentheses '()', comma ",", nothing can be used within the symbol name of a handle only the symbol of undeline '_', which is used to replace the blank And speaking of blank, the fourth rule is just that: Identifiers can not contain blanks. The fifth rule is that an identifier can not have letters with accents.

So, for example, acute accent ( ') caret (^), tilde (~), C cedilla (ç) no identifier can be accented characters. And the last rule is: you can not be a reserved word. And then you can ask me, "But, Guanabara, which would be a reserved word?

" I'll open again the VisuAlg and I will show you what is a reserved word. In VisuAlg, reserved words typically appear underlined or in a shade of blue. So in my case here O, "algorithm" is a reserved word, "Var" is a reserved word, "Start" is a reserved word, "Escreval" is a reserved word and "fimalgoritmo" is also a reserved word.

You can not use any of these words, or several other words that we'll see such identifier names. So knowing these six rules, I'll show some examples of identifiers, and we will reach an agreement here if they are valid or not. The first identifier that we will see is the "Note 1" "Note 1" follows six rules: it begins with a letter, the others can be letters and numbers, does not use any symbol, does not contain blanks, It has no accented and is not a reserved word.

So "Note 1" is a valid identifier. The "average" handle, at first, seems a valid identifier: it starts with letters, has letters and numbers, has no spaces, has no symbol, but it hurts the fifth rule, which is: "Can not contain letters with accents" In the case, "average" is the E sharp. So this name is not used for a variable identifier.

The next example is "Gross Salary". And in this case, you will see, right away, that two rules are injured: First, the word "salary" has accent, hurts the fifth rule, and between "Salary" and "Gross" you have a space, it hurts the fourth rule. In our case here, "Gross Salary" is an invalid handle.

And we would solve it by removing the accent of the letter The "Salary" And instead of space, or eliminate it or use the underscore symbol. The fourth example identifier is "9dade" He drew the catch? "9dade", besides a bad name, is an invalid handle, this because it hurts the first identifiers naming rule, which is: "You must start with a letter.

" Thus, "9dade" is an invalid handle. The fifth example is "algorithm": "Algorithm" begins with a letter, has several other letters later, does not contain space, does not contain symbols, it contains no accents, but it can be an identifier That's because, "algorithm", as we have seen, is a reserved word. The latest example is "Inicio_Algoritmo" and then there's another catch: The word "Start" is a reserved word, the word "algorithm" is a reserved word, but the addition of "Home" with "algorithm" is not configured as a reserved word.

Thus, starting with a letter, contains accents, contains symbols, It has an underline there, but it is blank, and is it all within the rules. So this sixth and last example would be a valid identifier name for a variable. Then write down those six rules because they will be very important further ahead.

Then we'll see the primitive types. So, as we have seen anteriorly We have in the variable declaration put the name indentificar we have seen the 6 rules for this, it is the primitive type. primitives constructed in VisuAlg, which is Portugol, there are 4 types.

Full, Real, Caracter and Logico. Let intender each. The Integer, will allow your variable store only integers.

If you remember well from your math lessons, you should know that some whole number of examples are: 1, 3, -5, 198, 0 integers are those numbers that are not fractional. Which has no fractional part, be it positive, negative or zero. The numbers that have fractional part, are numbers reais.

Such as 'medium', '5', '9. 8', '-77. 3' and our famous PI, which is the '3.

1415' something. Important to say here that in the case of 'Portugol' The '0. 5' (zero point five), he is not acting with commas, it is represented with point.

And it follows in all programming languages ​​that we will develop. It is important to say here that for example:  '5. 0' (five point zero) is a real number More is also an integer is the number '5' (five).

In mathematics you know, that interios numbers are contained in the group of real numbers. So if you need a whole number declare the variable as a whole If need the fractional part, declare as real. The treceiro type is the character type.

Character is all that is placed between quotation marks For example, the message "Hello World" we saw anteriorly, is a sequence of characters. Three other examples are "Gustavo" "algorithm" and "123" And you can ask me, hey Guanabara 123 is one hundred twenty-three it is an integer. No!

If it is in quotation marks 1 2 3 is a sequence of characters "1 2 3" It is important to say here that the string can contain yes accents. Within quotes you can use symbols, accents. And that does not follow the six identifiers naming rules.

Finally, we have the logical type, which saves only two values, TRUE and FALSE. So these are the primitive types that you keep within the VisuAlg. The two numeric types are INTEGER and REAL, the CHARACTER type that is strings and numbers And the LOGICAL type, which saves only true and false Let's go back now to VisuAlg and we will see how we can build the same example In another way, using variables Thus, in a previous screen, we saw the area of ​​variable declaration And it is made by a TAG, followed by COLON, followed by TYPE Now you know the rules for naming identifiers And you know the FOUR types that you can use So let's create an example here!

We can put in the field a variable called VAR MSG That's the type character MSG is the name of a fully valid identifier It begins with a letter, it is followed by other has no spaces, no accents, is not a reserved word There's nothing that makes it unusable Let's put this line there in our VisuAlg - Open VisuAlg - So we'll put here in VAR The variable MSG That's message, COLON, CHARACTER Note here "O" (mousse pointing) that as soon as I put CHARACTER he has stressed to me At the time you make that statement, you create the line One thing happens in your computer's memory. Let's see what it is As we saw earlier, our computer's memory It is like this cupboard full of empty caninhos When I put there my "VAR, MSG: character" What will happen is that the system will place in your computer's memory A sort of label, and will say that this space MSG is called to save messages that are of type character The line of reasoning is the same as when I used ball toy type Now I have a message that is a string in quotes So, we can, for example, pick up a piece of paper Write a message, "HELLO, WORLD! " And as "Hello, World!

" Is a message that is in quotes, we can put this type of message Directly in our variable And for that you will have to learn the concept of assignment In our case here, we have the variable MSG, type character declared To make an assignment we will type exactly this line, MSG gets "Hello, World! " The assignment symbol is exactly this symbol LOWER (<) followed by the MINUS (-) The representation of the assignment symbol is as if he had an arrow So If you look on the right side it says "Hello, World! " and the left arrow is written MSG.

I will read the following: The variable MSG will get the message "Hello, World! ". It's like I had this side to that side variable MSG and the message "Hello, World!

" I will give this message the variable is as if I took this message and played within the MSG variable, this is done the assignment. And as we can not enter an arrow on the screen, we will use the characters: SMALLER sign (<), MINUS (-) with no space between them. Let's see how this works So we'll just after the start put the MSG variable getting "Hello, World!

" Now, since I have the phrase "Hello, World! " within the MSG variable, I do not need more of that WRITE "Hello, World! " I can put: WRITE MSG I'll take this second WRITE here And that's how people usually think that the thing will work only that in fact we will have a little problem and I will now explain what is going to happen!

We will first run the program the way it's there, running this program: what will be exebido is MSG And then you will be in doubt, Poxa more I told him to write MSG! And that was exactly your mistake because "MSG" in quotes is a string so if you give the WRITE command or ESCREVAL "MSG", he will write on the "MSG" To resolve this problem, we'll have to take the quote here and put WRITE (MSG) we run the command and now we have the message Hello, World! on the screen I hope you have understood here the difference between MSG and MSG variable string Here in my case I created in memory of my computer a variable MSG And then you'll look down here Do you have a variable MSG type character, and the value in it is "Hello, World!

" The value that is inside of it is done after the award so I'm going to get "Hello, World! " I will play in the MSG variable and soon I will write on the screen the contents of the variable. And there are still a few extra tricks to using the WRITE command or ESCREVAL command that are the output commands VISUALG In the first instance there was what we saw earlier WRITE "MSG" in quotes, will write on the screen exactly MSG The second example WRITE MSG without quotation marks, will write the contents of the variable MSG this variable has to be declared and initialized The third example he will write two things: Note then he will put WRITE the "message" comma (,) MSG Basically what I'm doing and have them show two things within the WRITE and I can do it without any problem First I sent word to show the message Then separated by comma (,) We will show the contents of variable MSG let's see how it works Let's put here in my ESCREVAL "message" comma (,) MSG let's run You will see that the result is "Message Hello, World!

" He appeared stuck? I just put here a space after the EME (M) so I'll write "message" a blank MSG running again "Message Hello, World! " You saw how it is simple, and these are the first steps of every class algorithm that you will have in your life you have to understand What is the basic structure of language Understanding what are variables, identifiers and primitive types and also know how to write something on the screen In the next lesson we will learn how to interact with the user For example: Go!

It appeared a question on the screen: What's your name ? there the user will type: My name is Jose And you will answer: Hello Jose, good morning to you? Good afternoon all right with you ?

Something like that So This will be done in the next class, where we start creating interaction with our user I hope you're enjoying this algorithm course This class was a little more extensive Because I needed to go all these concepts to you More I wanted to again thank very presence I wanted to thank you very For you have come here to the Course algorithm ongoing Video Nice to meet you my name is Gustavo Guanabara I am your teacher And we will now have several algorithm classes Until you create a routine to build programming logic in your head And programming logic is equal to ride a bike! It's like driving a car! When you learn to drive car or ride a bike You wonder what you have to do Heck, the car I have to .

. . Tighten clutch, move the gear, turn the steering wheel After a while it just becomes automatic When you are learning to build algorithms You'll end up writing quite algorithm On paper or VISUALG which is the tool that I showed you After a while the algorithms they will already showing up in your head automatically And you're doing it directly in programming languages More I say again: You are still in early stages, do not try to run!

Try to walk slowly exercise, practice, because that's how you'll learn algorithm. I wanted to once again make some requests for you First: Clicking on this button you will enroll in the Course Video Here whenever you have a new course a new class Clicking here! And if entering the channel and putting there that you want to receive notifications by email You will, whenever you have a new class You will be warns before everyone else.

By clicking here you will have access to all classes of algorithm course That have been created to date Then you are in this second class If you already have the third class clicking here you will see that the third class is available, third, fourth As necessary for us to build this course An easy way for you to understand And I will also give some addresses so you always get the content we produce always free So our course design in video, it is available on the Internet Free on site www. cursoemvideo. com accessing there You will have access to all the courses that have already been created, including the course of HTML5 we just provide Totally there are 36 full lessons and free for you Then there cursoemvideo.

com access, you will have access to this sensational HTML course Our video channel on YOUTUBE is YOUTUBE. COM/CURSOSEMVIDEO It has a "S" there it is a little detached Our website is CURSOEMVIDEO Our channel is CURSOSEMVIDEO And the same with FACEBOOK You will access there FACEBOOK. COM/CURSOSEMVIDEO And you'll also have access to our posts FACEBOOK is cool that we sometimes put Studio photos, personal photo editing internals production of video courses We available there on FACEBOOK always for everyone That's it, it comes to an end more a lesson from your current algorithm video I hope next week You are there available for you to access your class The classes always leave on Mondays Close lunch 10:30 ~ 11:00 am Before you go to lunch, you take a studied Lunch, fills the belly after watching will new class In order to internalize in order to fixed content This is how you will learn algorithm, so that you will become a programmer You will find me there by Brazil and say: Holy crap I learned to program with you!

I am very happy, I'm very proud of it A big hug to the next, good studies and more. WRITE he is sending write, and you type a side . .

. . Blimey Burped, .

. . .

. . .

the WRITE command does.