Converting Fahrenheit to Celsius rounding error

[ripken2]

I'm trying to write a temperature converter for my class but whenever I put it through testBed I have a rounding error and have no idea how to fix it. testBed puts the code through 5 tests, which it passes all but one. When you put in 0 fahrenheit it comes out to -17.777 Celsius, so it is expecting it to round to -18 but my code rounds it to -17. I've looked, but can't seem to find out how to get it to round correctly... Does anyone have any hints or help for me?

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{

   //Declare variables
   int f;
   int c;

   //Ask for inputs
   cout << "Please enter Fahrenheit degrees: ";
   cin >> f;
   cout << setprecision(3);

   //Display input in celsius
   c = 5.0 / 9 * (f-32);
   cout << "Celsius: " << c << endl;

   return 0;
} 

[bird1234]

use round function

#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;

int main()
{

	//Declare variables
	float f;
	float c;

	//Ask for inputs
	cout << "Please enter Fahrenheit degrees: ";
	cin >> f;
	cout << setprecision(3);

	//Display input in celsius
	c = 5.0 / 9 * (f - 32);
	cout << "Celsius: " << round(c) << endl;

	system("pause");
}

[ripken2]

Thank you! I didn't know there was a round function...

[Handy Andy]

Hello ripken2,

I once solved this problem by setting "setprecision(0)" before the output of the actual number.

Hope that helps,

Andy

[jlb]

You will also have fewer "rounding errors" if you use a double instead of a float for your numbers.