DSA NOTES - 2
This is the 2nd lecture of our DSA series. We will see how a program runs and what does each
line mean in this lecture. This is how the compilation process work So it is compiler which
makes it possible for us to run a source code. Coding Ninjas has supported us in providing this
amazing DSA course to you. Courses are available in both Hindi and English. you need an IDE to
write, run and execute a code. There are many IDEs out there - CodeBlocks, VsCode and many
more - which you do n't even need to install Replit is one of them. You can directly create a C++
there and run it using Replit. In C++, many namespaces are there which have cout functions in
them so if we want to use cout , we have to add this file to our code. We use these signs to
output the result into standard namespace. If you will use > > by mistake by mistake, then it will
give you compilation error So we use this operator to display output.
We are going to talk about data types and variables. Whenever you have to story any
information or data in the memory. You have to mention what type of data it is and how much
memory it will take. For eg- int a = 5, a is a variable in memory which is of int type and it has
value 5 in it. We have certain rules which we have to follow when we are giving names. There is
a function named sizeof , which will tell you about the space being used by any variable. In
memory, first 29 bits will have 0, and last 3 bits will be 101, so in memory the first 29 bit will
have 0 and the last 3bits will have 101. We have a way to story multiple characters but we will
see that in upcoming lectures. In c++, all the characters are mapped to some ASCII value in
memory. We will just store binary form of ASCII value of any character. If we have 4 different
bytes with some binary value, how will compiler know whether it is a single Int value of 4
separate char values ? Compiler will come to know from data types which we used when we
declared any variable. This process of converting one data type into another is known as type
casting.
There are few steps which I have to follow while storing a negative number. Let 's say the
number is -5 1st - Ignore the negative sign 2nd - Convert into binary representation = 101 3rd -
Take 2 's complement and store it Now we can store negative numbers simply too, by just using
their first bit as their sign. With this our maximum value will be limited to 2^31 -1 instead of 2^32
-1. 2/5 will give 0 and not 0. 4 , why ? because you are storing your answer in a int variable. To
get answer in float, store it in a float variable. If you want to check whether A is equal to B or not
I can do that using this ( a==b ) relational operators = , > , < , ! = is an assignment operator,
Made by:-Ashish Khatwani
This is the 2nd lecture of our DSA series. We will see how a program runs and what does each
line mean in this lecture. This is how the compilation process work So it is compiler which
makes it possible for us to run a source code. Coding Ninjas has supported us in providing this
amazing DSA course to you. Courses are available in both Hindi and English. you need an IDE to
write, run and execute a code. There are many IDEs out there - CodeBlocks, VsCode and many
more - which you do n't even need to install Replit is one of them. You can directly create a C++
there and run it using Replit. In C++, many namespaces are there which have cout functions in
them so if we want to use cout , we have to add this file to our code. We use these signs to
output the result into standard namespace. If you will use > > by mistake by mistake, then it will
give you compilation error So we use this operator to display output.
We are going to talk about data types and variables. Whenever you have to story any
information or data in the memory. You have to mention what type of data it is and how much
memory it will take. For eg- int a = 5, a is a variable in memory which is of int type and it has
value 5 in it. We have certain rules which we have to follow when we are giving names. There is
a function named sizeof , which will tell you about the space being used by any variable. In
memory, first 29 bits will have 0, and last 3 bits will be 101, so in memory the first 29 bit will
have 0 and the last 3bits will have 101. We have a way to story multiple characters but we will
see that in upcoming lectures. In c++, all the characters are mapped to some ASCII value in
memory. We will just store binary form of ASCII value of any character. If we have 4 different
bytes with some binary value, how will compiler know whether it is a single Int value of 4
separate char values ? Compiler will come to know from data types which we used when we
declared any variable. This process of converting one data type into another is known as type
casting.
There are few steps which I have to follow while storing a negative number. Let 's say the
number is -5 1st - Ignore the negative sign 2nd - Convert into binary representation = 101 3rd -
Take 2 's complement and store it Now we can store negative numbers simply too, by just using
their first bit as their sign. With this our maximum value will be limited to 2^31 -1 instead of 2^32
-1. 2/5 will give 0 and not 0. 4 , why ? because you are storing your answer in a int variable. To
get answer in float, store it in a float variable. If you want to check whether A is equal to B or not
I can do that using this ( a==b ) relational operators = , > , < , ! = is an assignment operator,
Made by:-Ashish Khatwani
