Compilare: user.cpp: In function ‘void df(int)’: user.cpp:14:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++){ ^ user.cpp: In function ‘void level(int, int)’: user.cpp:55:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ^ user.cpp: In function ‘void df1(int, int)’: user.cpp:61:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[nod].size();i++) ^