Compilare: user.cpp: In function ‘void sift(int)’: user.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(f1<h.size() && dist[h[f1]]<dist[h[son]]) son=f1; ^ user.cpp:37:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(f2<h.size() && dist[h[f2]]<dist[h[son]]) son=f2; ^ user.cpp: In function ‘int main()’: user.cpp:74:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G[nod].size();i++) ^