Compilare: user.cpp: In function ‘void df(int)’: user.cpp:29:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[x].size(); ++i) ^ user.cpp: In function ‘void create(int)’: user.cpp:37:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[x].size(); ++i) ^