// This program is a modification of our earlier program runtime.cpp.
// This sends a warning message to the user if data are entered that
// will lead to a runtime error.  It illustrates the use of the if
// statement.  Make sure you use == instead of = to test equality in
// an if statement.

#include<iostream.h>
#include<cmath>

void main() {

  int a,b;
  double x,y,z;

  cout << "Enter 2 integers: ";
  cin >> a >> b;
  x = 1./(a-b); 

  if (a==b)
    cout << "Next time, enter two DISTINCT integers." << endl;

  cout << "1/(" << a << " - " << b << ") = " << x << endl;

  cout << "Enter a real number: ";
  cin >> y;

  if (y<0)
    cout << "Next time, enter a NONNEGATIVE real number." << endl;

  z = sqrt(y);

  cout << "The square root of " << y << " is " << z << endl;
}