C++ using Namespace continues Program

Program 6

#include 

#include

#include 

using namespace std;

int main() 

{

   cout << fixed << setprecision(1);

   int i1 = 4, i2 = 8;

   cout << i1 / i2 << endl;           

   cout << (double)i1 / i2 << endl;   

   cout << i1 / (double)i2 << endl;   

   cout << (double)(i1 / i2) << endl; 

   double d1 = 5.5, d2 = 6.6;

   cout << (int)d1 / i2 << endl;      

   cout << (int)(d1 / i2) << endl; 

   d1 = i1;             

   cout << d1 << endl;  

   i2 = d2;             

   cout << i2 << endl;  

}

Program 7

#include 

#include

#include    

using namespace std;

int main() 

{

   double celsius, fahrenheit;

   cout << fixed << setprecision(2);

             cout << "Enter the temperature in celsius: ";

   cin >> celsius;

   fahrenheit = celsius*9/5 + 32;

   cout << celsius << "C is " << fahrenheit << "F" << endl;

   cout << "Enter the temperature in fahrenheit: ";

   cin >> fahrenheit;

   celsius =  (fahrenheit - 32)*5/9;

   cout << fahrenheit << "F is " << celsius << "C" << endl;

   return 0;

}

Program 8

#include 

#include

#include 

using namespace std;

int main() 

  {

   int upperbound;

   cout << "Enter the upperbound: ";

   cin >> upperbound;

   for (int number = 2; number <= upperbound; ++number) 

   {

            int maxFactor = (int)sqrt(number);

      for (int factor = 2; factor <= maxFactor; ++factor) 

        {

         if (number % factor == 0) 

         {   

            cout << number << " ";

            break;   

         }

      }

   }

   cout << endl;

   return 0;

}

Program 9

#include 

#include

#include 

using namespace std;

int main() 

{

   int upperbound;

   cout << "Enter the upperbound: ";

   cin >> upperbound;

   for (int number = 2; number <= upperbound; ++number) 

   {

      int maxfactor = (int)sqrt(number);

      bool isprime = true;  

      for (int factor = 2; factor <= maxfactor; ++factor) 

      {

         if (number % factor == 0) 

         {   

            isprime = false;   

            break;   

         }

      }

      if (isprime) cout << number << " ";

   }

   cout << endl;

   return 0;

}

Program 10

#include 

#include

#include 

using namespace std;

int main() 

{

   int upperbound;

   cout << "Enter the upperbound: ";

   cin >> upperbound;

   for (int number = 2; number <= upperbound; ++number) 

   {

      int maxfactor = (int)sqrt(number);

      bool isprime = true;

      int factor = 2;

      while (isprime && factor <= maxfactor) 

       {

         if (number % factor == 0) 

        {   

             isprime = false;

         }

         ++factor;

      }

      if (isprime) cout << number << " ";

   }

   cout << endl;

   return 0;

}