Compilare: user.cpp: In function ‘void df1(int)’: user.cpp:14:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++){ ^ user.cpp: In function ‘void df2(int, int)’: user.cpp:27:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++){ ^ user.cpp:33:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<a[nod].size();j++) ^