C++ Program on Example of Pass-by-Reference

      #include <iostream.h>
   #include <stdlib.h>
   int exp (int,int);
   void readnums (int&, int&);
   void main ()
   {
     int b, e;
     readnums(b,e);
     cout << b << " to the " << e << " = " << exp(b,e) << endl;
   }
   void readnums (int& b, int& e)
   {
     int correctInput;
     cout << "Enter the base and the exponent: ";
     cin >> b >> e;
     if (!cin)
     {
       cout << "Disaster! Terminating program." << endl;
       exit(-1);
     }
     correctInput = (b >= 0) && (e >= 0);
     while (!correctInput)
     {
       cout << "Something wrong! Try again ..." << endl;
       cout << "Re-enter base and exponent: ";
       cin >> b >> e;
       if (!cin)
       {
         cout << "Disaster! Terminating program." << endl;
         exit(-1);
       }
       correctInput = (b >= 0) && (e >= 0);
     }
   }
   int exp (int b, int e)
   {
     int result;
     result = 1;
     while (e != 0)
     {
       result = result * b;
       e = e - 1;
     }
     return(result);
   }