How to signify no more input for string ss in the loop while (cin >> ss)

Question

I used \"cin\" to read words from input stream, which like

int main( ){
     string word;
     while (cin >> word){
         //do sth on the input word         


        

Answer 1

Hit Ctrl-Z (Ctrl-D on *nix systems) and hit enter. That sends an EOF and invalidates the stream.