🔥Principle of Programming Using C | BCA 2nd Semester PYQ Paper Solution | DAY-04

Indexado: 2026-05-21

[00:00:05]Come on brothers, hello and welcome all of you children to your channel Unique Online Guru. I am Nitin Srivastava, it is time for the C language class, so let's start the class without any delay. Children, in the last two classes that I took for C language papers, I started the questions of section A and section B and also got them solved. I have explained it to you and I hope that you must have liked its questions, the pattern of solving them and the most important thing is that I want to know whether you liked the class or not, you can give your feedback. My whole effort is to help you as much as possible. I can get as many questions solved as possible. Hello Sir. Okay R Computer Science you are Rajan Chaudhary sir. Welcome Rajan Chaudhary ji. You are very welcome to our YouTube channel. I hope you are doing very well. So it's time to start class. Let's talk less and start studying. So late start. Let us show you what are the questions of today's paper. So kids today I am going to start your third section of section C.

[00:01:30]And in this section Attempt Any Two Questions from Number of Questions there will be two questions i.e. big questions. The value of each question is 15 marks. That is, large which is called long answer question.

[00:01:48]Look at the long answer types, know one thing here that this is not a non-technical study where there are short questions here. It's a long question. Long answer type questions are powerful because of their content.

[00:02:04]It does not matter which section he comes from. If the question is good then it will be explained automatically. If the question is not strong then you will not be able to push it much. So with the hope that you are ready now? Let me take the first question in today's class.

[00:02:22]What is a first question? Look at the question.

[00:02:24]A define an array of third what? You create the array.

[00:02:32]Tell me what is it? Explain 1D and 2D arrays and saying write a program to multiply two matrix. I had told you the example of matrix addition in the previous class.

[00:02:44]Remember if you have joined us in this class. Today, instead of adding the matrix, you are being asked to multiply the matrix. So first let us cover the theoretical area.

[00:02:58]Then we will discuss further. Come on brothers, let's all start today's class.

[00:03:11]What is the first question? What is an array?

[00:03:18]What is this array? So let's go and see.

[00:03:24]An array is the collection of similar data types. The simplest, shortest definition, if any, of an array is possible. The smallest definition, if any, of an array is in front of you. What is array? This is a collection. Whose collection is this? This is a collection of similar data types or similar data items. Similar means if it is an array then if the value in it is integer then all will be integer. If there is float then all will float. If there is a character, then all characters will be there. It cannot be that there is a mixture. Four should be floats, two should be characters, and one should be an integer. It is not possible. An array will always be a collection of children of similar data items. So now the question arises, how many types of arrays are there?

[00:04:43]You will talk about types.

[00:04:50]If we discuss about array types, then see, there are mainly two types of arrays, children.

[00:04:59]One is your single dimension and the other is yours, you have asked, here I am discussing only that.

[00:05:20]Double Dimension We are here discussing about two types of arrays. One which you can call single dimension, children. And the second one which you can also call double dimension array. First of all let's talk. Who are you talking about? Single Dimension Array Key We're talking here about single dimension. Come on, what would you call a single dimension array? Will anyone among you tell me?

[00:06:10]So such an array is the array that only has a single axis.

[00:06:34]An array having only one axis is called a single dimension array. Whether it could be the x axis or the y. Look, if you created it like this, let's say the array is named A 10 20 30 40 50, okay, now axis zero, what would you call it, sir, you would call it a single dimension array. There is only one axis here and its number is zero. That could be x.

[00:07:18]That could be y. Ok?

[00:07:22]You would call such an array a single dimension array. In simple terms, an array that requires a single index value to access the element to be stored or displayed is called a single dimension array. And if you talk kids about multidimensional array, not multi, here we talk about array. It is said like this in the paper.

[00:07:57]So sir, what would you call a 2D array? Please look carefully children.

[00:08:10]See here.

[00:08:26]These are two axes here. One axis zero axis one.

[00:08:40]We children also call this array by another name.

[00:08:43]It is called Matrix.

[00:08:48]What is this called? This is also called matrix. What is this called, my children? This is also called matrix.

[00:08:56]And remember, here you have to access the element, otherwise double index value will be required. How many index values ​​do you need, son? Two index values ​​are required.

[00:09:08]Single dimension single index value. Double dimension double index value. That means here there is an x ​​axis, there is a y axis. Both axes are used and in single dimension there is only one axis, whether it is horizontal i.e. x or vertical i.e. y. So this is a technical mechanism.

[00:09:30]If someone asks you how to declare it? How to declare a single dimension.

[00:09:46]I will tell you both.

[00:09:50]How do you declare a single dimension, kids?

[00:10:11]Rajan Chaudhary ji, I can explain this code that you have written, but right now is not the moment for its explanation, you can ask for it separately, I will let you explain, son, let me tell you the question in the paper because the children have exams, okay, and his exam is near, I will explain it, there is nothing in it, a function has been declared and external storage class has been used in it. But this is not a movement. Please don't do this now.

[00:10:40]Time will increase.

[00:10:42]Please let me solve the questions I have now. I will explain. You know I will get it done.

[00:10:45]What I am trying to explain.

[00:10:48]Look very carefully children. How to declare a single dimension array.

[00:10:55]I will explain how to create a single dimension array.

[00:10:59]Ok? How do you declare a single dimension array? So children, what will you write first?

[00:11:12]You will tell its syntax and the type of data.

[00:11:18]Then what will you give? The name of the array.

[00:11:26]And what will you give in brackets? Its size.

[00:11:35]Children, please watch this carefully.

[00:11:41]Try to understand this carefully.

[00:11:45]First you will specify the data type. Then we will name the array and finally what will we name it? I will give you the size. So if you look at this, I declared int a of 5 equals 2 3 4 5 6, so what did I do here? A single dimension array is created.

[00:12:19]Darpan Kushwaha ji, hello son.

[00:12:21]You are most welcome. A single dimension array is created named A. It is a size five.

[00:12:28]Its data type is integer. Meaning, this array will hold five integer values in memory. And see, I have initialized it, that is, declared the array and also initialized it. Both these statements have been made together. And if someone says how to declare 2D array kids how will you be able to declare 2D array?

[00:13:01]So if you want to declare a 2D array, the first thing you need to do is type and name the array.

[00:13:20]Then what will you tell me?

[00:13:23]Tell Ro.

[00:13:25]Then what will you tell me?

[00:13:27]Tell the call.

[00:13:31]And give a semi colon.

[00:13:34]Look carefully. What is your method?

[00:13:37]This is the easiest way to declare a 2D array as children.

[00:13:44]How will it happen in this? If you have given int A, look carefully.

[00:13:53]3 / 2 Do you know what this means? There will be three rows and two columns, so there will be six elements in it. 1 2 4 5 6 See how this six element array will be arranged in the memory 1 2 3 4 5 6 0 1 2 0 1 What is the name of array AR if you try to understand it. So look at this, 0 1 2 are days and this 0 1 which is written here are calls.

[00:14:48]Ok? So this is your way of managing.

[00:14:50]Whom? There is a way to manage and handle two-dimensional arrays, children.

[00:14:57]What is your one? It's everyday. What is your one? There are columns. You can create a matrix using rows and columns.

[00:15:04]So the declaration is very simple. It is very easy. It is very simple.

[00:15:10]And children, if the question paper is saying how to or how to, it is not saying multiply to matrix.

[00:15:33]So children, how is a matrix multiplied? Let me try to explain that to you. Please try to understand it very carefully. The multiplication in a matrix always happens like this.

[00:15:48]Let's say this is your matrix.

[00:15:54]This is your second matrix.

[00:15:59]And after multiplying their result, you can take it like this also.

[00:16:13]Its name is A. Let's name it this matrix C. CB will see what do you mean we want to do? C = A multiplied by what? From B. If you need to multiply such a matrix. How does it happen children? Remember, its row element will be multiplied by its column element.

[00:16:44]That means if it is written here 2 3 4 5 6 then 2 will be multiplied by four first and will give 2 * 4 = 8. Look carefully, what will be the multiplication of three?

[00:17:01]What will happen to this? column. Please try to understand. And what happens here is that the elements of both have to be kept equal. Only then will I be able to become a Gulah properly.

[00:17:16]So look, let me restructure it a little bit.

[00:17:19]You have to explain.

[00:17:24]This is C equals A * Just give me 2 minutes. I will clear it.

[00:17:44]What is this of yours? B is. Now you see, suppose it is 2 3 4. Here is 1 2 5. So tell me the multiplication of row by the element of column.

[00:17:57]How it will happen? Please try to understand. Two multiplied by one will give two here.

[00:18:04]Make one more row.

[00:18:08]Three multiplied by two is six. Multiplying four by 5 will give 20. See, row A will be multiplied by column B and where will the result go? will go to row C. And you can do this comfortably even if you have children. This will happen through nested loops. I am writing that loop.

[00:18:27]I N T i j You have to declare such variables.

[00:18:36]for i = 0 i < = 2 is three, right i++ for j = 0 j < < = 2 j + and what will you write in it? IJ of C means the element of the first array of A in the row of C is from the column of the second array, so if you want the column then you will have to do JI. Just need to change this much.

[00:19:26]Look at this, son.

[00:19:28]You just have to do this. Just do this much.

[00:19:32]Your matrix multiplication will be done easily, kids. Your matrix multiplication will be done easily.

[00:19:40]What did you do here? ij in ij of C means the element of row in C plus the element of row in A and the element of column in B.

[00:19:53]Which is explained through this picture.

[00:19:55]For that, here IJ of C, so this is the row of C, if you give equal IJ IJ of A then it will take from the row. If you multiply B by JI JI then your horror vertical will start running like this. I have told you this trick.

[00:20:22]I am sure you will do it.

[00:20:24]Now let's move on to the next question.

[00:20:26]Spent a lot of time on this.

[00:20:35]What is this, look at this binary search tree, look at this, your question is not of C. This is a question of your data structure.

[00:20:45]This trick is to ask you for preorder, inorder and postorder traversal.

[00:20:54]What is a binary search tree? Where each root element can have at most two children. Now it can be less than two, it cannot be more than two.

[00:21:07]That is, the degree of any node cannot be more than two.

[00:21:10]So there is no point in taking up this question here. Let us take up the question of C. I think it is better.

[00:21:18]Look at this question, it is a very good and simple question. Do this. This second question is to write a C program to interchange the value of two variables without using any third variable. This is called swiping for children. This is a very good question. This is a very good question and it can be solved easily in less time.

[00:21:39]Let me show you.

[00:21:42]How to interchange the value of two variables without using any third variable. Come on, this question is considered a very good question.

[00:21:50]Let me show you.

[00:21:54]Look, I am writing a program comment.

[00:22:01]To swipe the value of two variables.

[00:22:16]How do you swipe the values ​​of two variables? So look kids, write the main function and create an integer variable, let's say the value of a is 10. The value of b is 20. The value of A is 10. The value of B is 20. We have to do the opposite. The value of B in A is to interchange the value of A in B.

[00:22:55]How to do it? So look, I am writing it directly in very less coding.

[00:23:02]Process to swipe.

[00:23:10]By what process are we going to swipe the elements?

[00:23:15]Try to understand this.

[00:23:19]a = a + b b = a - b a = a - b Look, this is done in three lines of swiping and all you have to do is print f equals a, what kind of variable is it? Print the integer a.

[00:23:53]print f b = b to get it printed. There are only three main lines. Just understand that. The rest is played out. You should print this out. It's very easy kids. If you try to understand this. The value of A is 10, the value of B is 20. Tell me what will be in the first line?

[00:24:21]What will be the value of a? 10 + 20 so A becomes 30 on this line. Look everyone try to understand carefully.

[00:24:30]a = a + b so 10 + 20 becomes 30. What will b be equal to? If the value of a becomes 30 and the value of b is 20 then 20 will be subtracted from 30. Then what will be the value of b? It will become 10. The value has reversed. The value of B is 10. Now see how much is A still equal to? 30. 30 - If the value of B is 10 then what is the value of A when 10 is subtracted from 30? It's 20. That means when you children print A here, the result will be 20.

[00:25:05]And if you print B then the result will be 10.

[00:25:08]And how is this happening? With whose help did this happen? This happened with the help of these three lines. This is what we call technique to solve, technique to solve, technique to swipe values, how easily, how many ways, how powerfully you are able to swipe the values ​​of your variables.

[00:25:29]Look kids, popularity happens with the help of the third variable.

[00:25:33]But if this has come in your exam then believe me this question can be repeated.

[00:25:39]This question can be repeated, how will you swipe without a third variable and while I am at it, I will also teach you how to do it if you want to do it using a third variable. If you want to take a third variable, then declare a variable named c, the value of a in c is c = a = b = c, just write these three lines, what is this method? Using third variable.

[00:26:24]This method was yours with the third variable.

[00:26:27]And what was the previous method? What was without using? The third variable was with. So you can see that you can do it very comfortably and in a very cool way through both the methods.

[00:26:45]Can solve things. So children, I have great hope that the question that I have brought for you will be answered. This hard work that I am doing with you. What will I get in return for this? All you will get is that if your papers go well then I will be happy. This is my only wish, this is my hope that you take this class and if some of your papers can be better then we will be very happy, especially me personally because a lot of hard work is put in with you on how we can access the value of a pointer variable.

[00:27:29]How can we access the value from a pointer variable?

[00:27:34]See the structure question given below.

[00:27:36]I got it done in yesterday's class.

[00:27:44]How do we access values ​​using pointer variables? Let me tell you this in brief and this will also end your paper.

[00:27:53]See what I have to tell you.

[00:27:58]Accessing value of variable using pointer.

[00:28:20]How can we access the value of a variable using a pointer? So come quickly and see it.

[00:28:28]Write the main function. I am not writing the entire program.

[00:28:30]Just giving you an overview.

[00:28:32]This will definitely be completed. I N T a = 10 comma asterisk ptr I discussed an integer variable and a pointer variable in the same line.

[00:28:46]Declared.

[00:28:49]I put A's address in the PTR. Now look at printf, look carefully, write a equals value of a equals percentage d and you have printed a and after this what will you write in its next line?

[00:29:17]print f value of a equals percentage d asterisk ptr done this will be your answer see you have created an integer variable my children what name integer variable created named a ok. So this is your A. You have set the value of A as 10. A has an address. 66310 Suppose you can accept this. empty you created a pointer variable ptr and what did you do in this line? The address of A is stored in the PTR. That means 66310 is stored in your PTR variable.

[00:30:12]Now if you simply print the value of A then you know that it will be 10. But how will the value of A be printed here using the pointer?

[00:30:21]When you write PTR, simple PTR, you will get this 66310 and the asterisk at this location means that you will get the value of this location. So what is the value of this location? The value of 66310 is your 10.

[00:30:41]So this is your way to access the pointer, kids. So I hope you're enjoying this class.

[00:30:57]I have tried to give a correct answer to every question in less length and with less technicality.

[00:31:00]So kids, this paper is over here. I will meet you again very soon with some new subject and some new paper.

[00:31:08]Now I want your permission for today and if you like my class then please keep subscribing to our channel so that in future I can keep bringing such excellent classes on different subjects. Be it Python class or C, web designing or IoT, O level exams are approaching. So maybe a new course, a crash course in which you can try to complete the course in the best possible way in less time.

[00:31:39]So with the confidence that you will join us. We will meet again. Thanks for joining us. Good night kids. Stay safe, stay healthy because the weather is very bad. Avoid the heat. Do not go out in the sun unless it is absolutely necessary.

[00:31:55]With this hope, we will meet in the next class.

[00:31:57]Hello son. Thank you. Jai Hind. Good night.