Compilare: user.cpp: In member function ‘interval interval::intersectWith(interval) const’: user.cpp:52:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (auto i = 0; i < v.size(); ++i) ^ user.cpp: In member function ‘int interval::sum() const’: user.cpp:69:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (ret = 1, i = 0; i < v.size(); ++i) ^