Fun C++ Problem

[RoboTact]

VC++6 compiler was a lot faster (to fail on wrong code) - but still took 30 minutes on 1GHz machine. Result is that there are indeed only 3 solutions.

- at 24:
int i, n = 20;
for (i=0;-i<n; i--)
{
cout << "x" << endl;
}


+ at 26:
int i, n = 20;
for (i=0; i+n; i--)
{
cout << "x" << endl;
}


n at 30:
int i, n = 20;
for (i=0; i<n; n--)
{
cout << "x" << endl;
}