Compilare: user.cpp: In member function ‘void nrm::operator*=(nrm)’: user.cpp:29:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size (); i++) ^ user.cpp:30:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0, t = 0, val; j < b.v.size () || t; j++, t /= 10) { ^ user.cpp:31:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] val = (t += v[i] * (j < b.v.size ()?b.v[j]:0) ) % 10; ^ user.cpp:32:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i + j >= c.size ()) ^