Compilare: user.cpp: In function ‘void df(int)’: user.cpp:11:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<c[nod].size();i++) ^ user.cpp:16:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<c[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:41:9: warning: the address of ‘b’ will always evaluate as ‘true’ [-Waddress] if(!b) ^