Compilare: user.cpp: In function ‘int nrE(std::__cxx11::string)’: user.cpp:51:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); i++){ ^ user.cpp: In function ‘int energie(std::__cxx11::string)’: user.cpp:63:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<s.size(); j++){ ^ user.cpp: In function ‘int BFS(int)’: user.cpp:80:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<graph[x].size(); j++){ ^