need help with cin and blank inputs

[bundy]

ok what seems to be tripping me up on a few of these contest is how to deal with a blank input such as a space or carraiage return. I am trying to use cin and can't seem to trap it.

I have tried

while(cin >> input)

but i loop forever.

[tenshi]

look at this example :

char s[maxlen];
cin.getline(s,maxlen);
istrstream strin(s);
while(sin>>x) cout<<x<<endl;

[arnsfelt]

or more robust:

[cpp]
string s;
getline(cin,s);
istringstream sin(s);
while(sin>>x) cout<<x<<endl;
[/cpp]