Need help with "nan" in my program

[greenberet]

Hey guys, i`ve just started studying programming and i`ve run into a problem i don`t know how to fix, its very very basic, but i`m a newbie, anyway i how you can help me out, because i saw someone with a similar program, but couldn`t quite understand how to fix it in my program.

#include <iostream>
using namespace std;

int main()
{
int a, b=0, n=0, c, ok;
double summa;

do
{
summa = 0;
cout << "Ievadi naturalu skaitli" << endl;
cin >> a;
if (a >= 0)

{
n=0;

if (a==0)
cout <<a<<endl;
while (a!=0)
{
b = a % 10;
a=a/10;
summa=summa+b;
n++;
}
cout << summa/n << endl;


}

else
{
cout <<"Ievaditais skaitlis ir negativs";
}
cout << " Vai turpinaat (1) vai beigt (0)?" << endl;
cin >> ok;
} while (ok == 1);
return 0;
}

when i enter 0 in the consule, he gives out the asked for 0 but the program also adds "nan" at the end, how do i get rid of it?

thanks for the support.

[Zugzwang]

In your program, you initialise n to 0 and only modify it if a is not equal to 0 (in the "while (a!=0)" loop).

Then you execute the following line:


cout << summa/n << endl;


Since n is still 0 when a was 0, you divide by 0 here, which results in "not a number"=NaN as the result.