fast input output cpp

Sure! Here is an example of how to perform fast input and output in C++:

#include <iostream>
using namespace std;

int main() {
    ios_base::sync_with_stdio(false); // Disable synchronization between C and C++ standard streams
    cin.tie(NULL); // Untie cin from cout

    int num;
    cin >> num; // Read input from standard input

    cout << "The number is: " << num << endl; // Write output to standard output

    return 0;
}

Explanation:

#include <iostream>: This line includes the input-output stream library in C++, which provides the necessary functions and objects for performing input and output operations.
using namespace std;: This line allows you to use the standard library functions and objects without specifying the std:: prefix. It saves you from having to write std:: before every standard library function or object.
ios_base::sync_with_stdio(false);: This line disables the synchronization between the C and C++ standard streams. By default, the C and C++ standard streams are synchronized, which can cause a decrease in performance. Disabling this synchronization can improve the speed of input and output operations.
cin.tie(NULL);: This line unties the cin stream from the cout stream. By default, the cin stream is tied to the cout stream, which means that the cout stream is flushed (output is displayed on the console) before any input operation from the cin stream. Untying them can improve the speed of input and output operations.
int num;: This line declares an integer variable named num to store the input value.
cin >> num;: This line reads the input value from the standard input and stores it in the num variable. The >> operator is used for input operations.
cout << "The number is: " << num << endl;: This line writes the output to the standard output. It displays the text "The number is: " followed by the value of the num variable. The << operator is used for output operations. The endl manipulator is used to insert a newline character and flush the output stream.
return 0;: This line indicates the end of the main function and returns the value 0 to the operating system, indicating successful execution of the program.