Compilare: user.cpp: In function ‘void dfr(int)’: user.cpp:37:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<A[h].size();++i) ^ user.cpp: In function ‘void df(int, int)’: user.cpp:69:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[h].size() && !ok;++i) ^