Compilare: user.cpp: In function ‘int main()’: user.cpp:36:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[x].size();i++) ^ user.cpp:49:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[x].size();i++) ^