Compilare: user.cpp: In function ‘bool fara_e(std::string)’: user.cpp:28:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); i++) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:36:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[nod].size(); i++) ^ user.cpp: In function ‘int get_energy(std::string)’: user.cpp:49:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); i++) ^