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

//---------------------------------------------------
// Calculate prime numbers and store in array
//---------------------------------------------------
void calculate_primes(int Value[], int NumPrimes)
{
   // Initialize prime value array
   int Count = 0;
   Value[Count++] = 2;

   // Loop over odd numbers
   int Number = 3;
   while (Count < NumPrimes)
   {
      // Check if Number is prime
      bool Prime = true;
      int Index = 0;
      while (Prime && (Index < Count) && (Value[Index] <= sqrt(Number)))
         if (Number % Value[Index++] == 0) 
            Prime = false;
      
      // Save prime in Value array
      if (Prime)
         Value[Count++] = Number;
      
      // Increment Number by two
      Number += 2;
   }
}

//---------------------------------------------------
// Main program calculates and prints prime numbers
//---------------------------------------------------
int main()
{
   // Get user input
   int NumPrimes = 0;
   cout << "Enter number of primes: ";
   cin >> NumPrimes;
   if (NumPrimes < 1) NumPrimes = 1;
   int Value[NumPrimes];

   // Calculate primes
   calculate_primes(Value, NumPrimes);

   // Print primes
   for (int Index = 0; Index < NumPrimes; Index++)
   {
      cout << Value[Index] << " ";
      if (Index % 10 == 9) cout << endl;
   }
   cout << endl;
   return 0;
}