5.21

/*  5.21 Modified Triangle-Printing Program
    Deitel & Deitel C++ How to Program, 10th ed. (Indian subcontinent adaptation)
    Visual Studio Community 2019
*/

#include <iostream>
using namespace std;

int main() {

   int y, row;
   int const MAX = 10;

   for ( row = 1; row <= MAX; row++ ) {

      // print asterisks for 1st triangle
      for ( y = 1; y <= row; y++ )
         cout << "*";

      // print spaces for 1st triangle
      for ( y = row + 1; y <= MAX; y++ )
         cout << " ";

      cout << " ";

      // print asterisks for 2nd triangle
      for ( y = 0; y <= ( MAX - row ); y++ )
         cout << "*";

      // print spaces for 2nd triangle
      for ( y = 1; y < row; y++ )
         cout << " ";

      cout << " ";

      // print spaces for 3rd triangle
      for ( y = 1; y < row; y++ )
         cout << " ";

      // print asterisks for 3rd triangle
      for ( y = 0; y <= ( MAX - row ); y++ )
         cout << "*";

      cout << " ";

      // print spaces for 4th triangle
      for (y = row + 1; y <= MAX; y++)
         cout << " ";

      // print asterisks for 4th triangle
      for ( y = 1; y <= row; y++ )
         cout << "*";

      cout << "\n"; // carriage return then back to loop
   }

   return 0;
}