Compilare: user.cpp: In function ‘bool verif(std::string)’: user.cpp:12:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i<s.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:28:24: warning: unused variable ‘lg’ [-Wunused-variable] int n = strlen(v), lg = 0; ^