A solution to Problem X (1 point)

Here is a solution to Problem X. This program demonstrates several things.

Good things

The use of assert(). This is the greatest command you can ever use. Use it lots. It will become your friend.

Simple I/O in C++

Not so good things

Breaking out of loops in the middle. In an ideal world you'd like to do something like:

	        while(condition){
	           process...
	        }

What would happen in the file existed, but was empty? What are we assuming about x1 and x2? (change int x1,x2 to int x1=1,x2; and find out).

asserting file I/O. If you were writing something that was to be more robust, you would:

	        if(!infile){
	           // output a warning
	        }

// Problem X solution by Stuart Inglis
    
#include < iostream.h >
#include < fstream.h >
#include < assert.h >

void main(void)
{
  int x1,x2;

  ifstream infile("PROBLEMX.DAT", ios::in);
  assert(infile);

  while(1){
    infile >> x1 >> x2;
    if(x1 == 0 && x2 == 0) break;
    cout << x1+x2 << endl; 
  }
}