// Ex4_09.cpp
// Calculating primes
#include <iostream>
#include <iomanip>
using std::cout;
using std::endl;
using std::setw;

int main()
{
  const int MAX { 100 };                         // Number of primes required
  long primes[MAX] { 2, 3, 5 };                  // First three primes defined
  long trial { 5 };                              // Candidate prime
  int count { 3 };                               // Count of primes found
  bool found { false };                          // Indicates when a prime is found

   do
   {
      trial += 2;                                // Next value for checking
      found = false;                             // Set found indicator

      for (int i {}; i < count; i++)             // Try division by existing primes
      {
         found = (trial % *(primes + i)) == 0;   // True for exact division
           if(found)                             // If division is exact
              break;                             // it's not a prime
      }

      if (!found)                                // We got one...
         *(primes + count++) = trial;            // ...so save it in primes array
   } while (count < MAX);

   // Output primes 5 to a line
   for (int i {}; i < MAX; i++)
   {
      if(i % 5 == 0)                             // New line on 1st, and every 5th line
         cout << endl;
      cout << setw(10) << *(primes + i);
   }
   cout << endl;

   return 0;
}