1.
      int main ()
   2.
      {
   3.
      .
   4.
      .
   5.
      .
   6.
      .
   7.
 
   8.
 
   9.
      ifstream file1;
  10.
      ifstream file2;
  11.
      ofstream simiralities;
  12.
      simiralities.open("P(0)_P(1).txt", ios::app);
  13.
      file1.open("test1.txt", ios::in);
  14.
       // A good way to check if a file has been opened-
 
      if (! file1)
 
      {
       cout << "error opening file" << endl;
       return -1;
      /*Your program isn't opening your files correctly, and will exit here. Have a gander & see what you can come up with*/
      }
  15.
      while (!file1.eof())
  16.
      {
  17.
      .
  18.
      .
  19.
      .
  20.
 
  21.
 
  22.
      file2.open("test2.txt", ios::in);
  23.
 
  24.
 
  25.
      while (!file2.eof())
  26.
      {
  27.
 
  28.
      .
  29.
      .
  30.
      .
  31.
      .
  32.
 
  33.
      }
  34.
 
  35.
      file2.close();
  36.
 
  37.
 
  38.
      }
  39.
 
  40.
      simiralities<<number;
  41.
      file1.close();
  42.
      simiralities.close();
  43.
 
  44.
      return 0;
  45.
      }