How many electrons are required to carry a charge of x coulombs

[emlynw]

I'm trying to learn c++ and was using physics school work to try and make a program.
One electron carries a charge of 1.6*10^-19 coulombs(C) and the program should show how many electrons are required to carry a charge of the number of coulombs entered by the user.
1 coulomb/1.6*10^-19 = 6.25*10^18 but the answer I get from the program is 6.25e+018. How do I get it to show the answer as 6.25*10^18? Thanks.

 #include <iostream>
#include <math.h>
using namespace std;

int main()
{
   double e = 1.6*pow(10, -19);
  cout << "enter the charge in coulombs: " << endl;
  int C;
  cin >> C;
  cout << C/e << " electrons are required to carry a charge of " << C << endl;
  return 0;
}

[chinchu]

Try to use std::setprecision()

[ne555]

> but the answer I get from the program is 6.25e+018
and that's a problem because...
http://en.wikipedia.org/wiki/Scientific_notation#E_notation