Recursion

Audio Transcript Auto-generated

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  Hello, everyone.

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  Today's lesson is about a new term that is used

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  in programming, which is called Rick.

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  Urgent. What is the Riker Shin on?

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  How it is used in programming.

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  This is what we will understand today.

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  So by the end of this lesson, you should be

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  able to understand the term.

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  Rick. Urgent Riker Shin is a general term that is

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  used in all types off programming.

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  This is one off the main concepts that you should

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  understand. Like when we started with programming.

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  I told you that there are some basic terms that

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  you have to know.

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  Like valuables, data, types, functions, procedures Ah, ee Library.

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  Now you know, Ryker Jin is one off the basic

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  things that you should understand in programming.

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  Let's see what the Rick urgent is before I tell

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  you. What do we mean by rick?

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  Urgent. Let us take a look as examples off real

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  problems that you may solve you may need to solve

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  by typing accord of it on.

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  Let's see how you are going to think about it.

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  I'm gonna give you three different problems on.

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  Let's think together how you can.

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  I think you're gonna think about the code for this

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  problem. Good sake.

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  And got the 1st 1 If you have this picture

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  and you have to draw to type accord that will

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  draw this tree How you should start thinking about this

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  If you remember when we started with a small deal

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  on, we said the 1st 2 step in computational thinking

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  or one off the steps and computation of thinking is

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  to divide your problem into smaller ones.

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  If I look at the street, I will see it.

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  This is very complex and I can't from where shall

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  I start drawing from the bottom from the top?

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  From which part exactly.

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  But if I start thinking about this problem, that is

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  a huge problem and I want to divide it into

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  smaller ones.

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  I may find it easier.

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  I may think about drawing each different port alone.

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  If you can see most off the leaves or the

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  salt parts that you have in the street.

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  Most of it are the same.

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  It has almost the same structure, so I may divide

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  it into smaller problems.

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  I may start drawing, are thinking about accord that will

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  sort of a part of it, and then this code

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  may be repeated later on to draw the rest off

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  the tree.

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  I may modify a part of it, but most of

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  the code will be repeated here.

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  Why? Because most of the leaves that look the same.

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  Okay, let's take a look.

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  Another one.

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  Let's see this math problem.

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  If I have this number number N, I want to

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  divide it by two on after I divided by two.

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  The answer that I will get should be divided by

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  four, and I'm repeating the step two times.

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  So let's say, if I have been 10 will be

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  divided into 10 by five, and I should repeat it

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  again into town by fight, divided by its sorry 10

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  divided by two on then which is five Iranian.

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  And then this process should be divided again, and another

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  time I have to divide it by four in two

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  different steps.

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  If you look at this program, you will see that

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  this is divided into two different steps on each step

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  is divided into another, too.

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  But if you compare the right side and the left

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  side, you will see that it's the same.

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  I'm repeating the same steps in my program two times.

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  So why do you think I need to type the

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  code two times?

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  I don't have to.

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  I will type one function that will perform a part

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  of the calculation, and I may call this function again.

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  So as we took and functions, I may define a

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  function that will perform this calculation for me.

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  And I may call it again and again and again,

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  depending on what, the times that you need to repeat

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  the function within your program until it performs the whole

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  action or the until it solves the whole problem that

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  you have.

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  This is cold.

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  Rick Ergin.

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  I'm repeating.

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  I'm re calling the same function more than one time.

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  Another example.

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  Look at this curved line.

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  Do you think if I want to draw this curved

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  line, I have to repeat or to do the steps

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  from the beginning till the end?

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  If I try to make my problem's simpler, I may

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  divided into two parts, and I will see that it's

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  very clear that what I'm doing on the left side

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  is the same as the one that I'm doing on

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  the right side.

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  So it is enough for me to call a function

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  or toe.

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  Define a function that will draw the left half off

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  The curse of line on I will call it again.

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  Two. Draw the right half side off The curse of

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  line This is cold, Riker Shin.

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  So what is the Riker Shin on DDE?

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  How it is used an incursion Is the process off

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  subroutine dividing a problem into simpler parts and call it

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  calling itself to solve those simpler parts.

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  When we were talking about the tree, we said I

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  can divide two smaller ones and I can type only

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  one chord that will, or one function that will draw

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  a part of it to complete the rest of the

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  tree. I will keep calling the function.

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  This function will keep calling itself in a loop until

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  I'm done with drawing the whole tree.

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  This is the main idea behind using that occur jh

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  in. So it's a function that keeps calling get safe

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  instead off um, typing the coat more than once.

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  I just think about my problem, which is a very

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  complex one.

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  I just divided into smaller problems that I define on

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  Lee a sobriety and whether a function procedure, whatever you

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  need in your code on dysfunction will keep calling itself

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  many times until I'm done with drawing or performing whatever

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  I need from my coat.

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  This is, in general what every courage and is.

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  And as you know, this is very important in your

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  code. This will save your time.

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  You don't have to think about the problem A in

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  a complex way and keep repeating your code.

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  You just divided into smaller ones.

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  This is what we call the computation of thinking, and

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  you type a piece off court that will keep repeating

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  itself and calling itself until the whole problem is solved.

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  After we discussed what is the record gin and you

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  understand that the term let's see what your task is.

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  I want you to think about different types of problems

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  that could be sold by a recursive coat.

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  Can you find different problems on?

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  Please think about different problem types.

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  I don't want it to be related or similar to

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  the ones that I showed it to you.

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  Please think about new ideas, new problems that could be

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  sold by a recursive code.

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  I'm waiting for your answers, and I'm sure that you

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  can if I gonna find a lot of problems that

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  could be sold by incursion Waiting for your answers.

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  If you have any questions, just ask me.

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  Have a good day.