Compilare: user.cpp: In member function ‘void SlidingMin::Push(int, int)’: user.cpp:13:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(left < size() && x <= back().first) pop_back(); ^ user.cpp: In member function ‘void SlidingMin::Pop(int)’: user.cpp:17:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(left < size() && at(left).second < p) ^ user.cpp: In member function ‘int SlidingMin::Query()’: user.cpp:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(left == size()) return kInf; ^