Bits stdc++.h in C++

<bits/stdc++.h> in C++

In essence, it is a header file that contains all the standard libraries. It makes sense to use this file in programming competitions to speed up work, especially if your rank is time sensitive.

People concentrate more on discovering the method to solve a problem in programming competitions than on software engineering. It makes sense from a software engineering standpoint to reduce the include. If you utilize it, it adds several files that your software might not need, which unnecessarily lengthens the compilation process and increases program size.

Negative aspects of bits/stdc++

• A non-standard header file of the GNU C++ library is bits/stdc++. h. Therefore, if you attempt to compile your code using a compiler other than GCC, it may fail; for example, This header is not present in MSVC.
• It would take longer to compile and include a lot of extraneous information if it were used.
• Since this header file does not adhere to the C++ standard, it is not portable and should be avoided.
• Furthermore, even if the standard provided a catch-all header, you should still use specific headers rather than it because the compiler must read in and parse each included header (including recursively had titles) each time that translation unit is generated.

Benefits of bits and C++

• Using this file during competitions is brilliant if you want to reduce time spent on duties, especially if your rank is time sensitive.
• Additionally, this lessens the laborious task of creating all the required header files.

For each function you use, you don't need to learn the full GNU C++ STL.

Example:

For instance, we don't need to include the math header file in the code to utilize the sqrt() method from the bits/stdc++.h header file.

#include <bits/stdc++.h>
using namespace std;
int main() {
	cout << sqrt(25);
	return 0;
}

Output:

5

However, to run the sqrt() function, if we use the iostream header file, we must also write the cmath header file. Otherwise, the compiler will indicate that "sqrt" was not declared in this scope.

#include <iostream>
#include <cmath>
usingnamespace std; 
int main() {
    cout <<sqrt(25);
    return 0;
}

Output:

5

Therefore, the user has two options for saving compilation time: either utilize it and avoid writing every include or don't use it and write the required header files.