#include <iostream>
using std::cout;
using std::endl;

#include <string>
using std::string;

int main()
{
   string string1( "abc edfgh ijk lmno pqr stu vw xyz" );
   
   cout << "Original string:\n" << string1 << endl << endl;

   int position = string1.find( " " ); // find first space

   // 
   while ( position != string::npos ) 
   {
      string1.replace( position, 1, "." );
      position = string1.find( " ", position + 1 );
   } 
   cout << string1 << "\n\nAfter second replacement:\n";
                
   return 0;
}  

/* 
Original string:
abc edfgh ijk lmno pqr stu vw xyz

abc.edfgh.ijk.lmno.pqr.stu.vw.xyz

After second replacement:

 */