Compilare: user.cpp: In function ‘int calc(int, int, int)’: user.cpp:18:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<=V[d].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:42:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<V[i].size();j++) ^