/* isPrime-eof.cpp
 * tests for primes using an eof-controlled while loop
 * does not employ a user-defined function
 * solution for Exercise 1, w1/isPrime-problem.html
 */

#include <iostream>
using namespace std;

int main(){
   int n,          //input integer
       pd;         //potential divisor

   //prompt and read n
   cout << "enter n > 1 (c-d to exit): ";
   cin >> n;

   //driver loop
   while(cin){

      pd = 2;
      //generate and test divisors
      while(n % pd != 0)
         pd++;

      //display result
      cout <<  n  <<  ((n == pd) ? "is prime " : "is composite" ) << endl;

      //prompt and read n
      cout << endl <<  "enter n (c-d to exit): ";
      cin >> n;
   }

   //exit
   cout << endl << "Exiting..." << endl;
   return 0;
}