why compilation is ok but exceed runtime?? thanks

Question

#include <iostream>

using namespace std;

int main()
{
    int f;
    cout << "Temperatura w skali Fahrenheita: ";
    cin >> f;
    cout << f << " stopni F to " << (f-32)*5/9;
    cout << " stopni C" << endl;
    return 0;
}

Answer 1

This runs fine for me.

Sometimes there could be interruptions to the Online GDB service, and then you'd have no output. You can try to run again and that usually solves the issue. Sometimes reloading the page helps (but save your work before!!!).

Answer 2

The problem with your code is in this line:

(f-32)*5/9

Since f is declared as int, the expression (f-32)*5/9 performs integer division. In C++, when you divide two integers, the result is also an integer (it truncates the decimal part). So 5/9 = 0 (not 0.555...).

This means your Celsius value will always be 0, regardless of the Fahrenheit input!

Fix: Use floating-point division by making at least one operand a double/float:

(f-32)*5.0/9.0

Or better yet, change your variable to double and use proper formatting:

#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
    double f;
    cout << "Temperatura w skali Fahrenheita: ";
    cin >> f;
    cout << fixed << setprecision(2);
    cout << f << " stopni F to " << (f-32)*5.0/9.0 << " stopni C" << endl;
    return 0;
}

This way the division will work correctly and give accurate Celsius values!