//---------------------------------------------------
// Purpose: Program to check for prime
//          numbers using a factoring approach
// Author:  John Gauch
//---------------------------------------------------
#include <cmath>
#include <iostream>
using namespace std;

void is_prime(int Number, bool &Prime)
{
   // Check if Number is prime
   Prime = true;
   if (Number == 1)
      Prime = false;
   for (int Factor = 2; Factor <= sqrt(Number); Factor++)
      if (Number % Factor == 0)
         Prime = false;
}

int main() 
{
   // Local variable declarations
   int Number = 0;
   
   // Read input number
   cout << "Enter a number between [1..1000]: ";
   cin >> Number;
   
   // Check input is valid
   if ((Number < 1) || (Number > 1000))
      cout << "Error: Number is out of range\n";
   else
   {
      // Print output
      bool Good = true;
      is_prime(Number, Good);
      if (Good)
         cout << "Number " << Number << " IS prime\n";
      else
	 cout << "Number " << Number << " is NOT prime\n";
   }
   return 0;
}