Compilare: user.cpp: In function ‘int main()’: user.cpp:17:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<=s.length();i++) ^ user.cpp:27:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<=s.length();i++) ^ user.cpp:29:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k==s.length()) {g<<s.length()<<"\n"; break;} ^