//---------------------------------------------------
// Purpose: Program to calculate prime factors
// Author:  John Gauch
//---------------------------------------------------
#include <cmath>
#include <iostream>
using namespace std;

// Function to check one factor
void Check(int &Number, const int Value)
{
   while (Number % Value == 0)
   {
      cout << Value << " is a factor\n";
      Number = Number / Value;
   }
}

// Function to calculate prime factors
void Factors(int Number)
{
   // Loop over all possible factors
   for (int Value = 2; Value <= sqrt(Number); Value++)
      Check(Number, Value);
   if (Number > 1)
      cout << Number << " is a factor\n";
}

// Main body of program
int main()
{
   // Get user input
   int Num;
   cout << "Enter number in [1..1000] range: ";
   cin >> Num;
   if ((Num < 1) || (Num > 1000))
      cout << "Number must be in [1..1000]" << endl;
   else
      // Calculate prime factors
      Factors(Num);
   return 0;
}