Compilare: main.cpp: In member function 'void Fenwick2D::fakeUpdate(int, int)': main.cpp:16:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 16 | for (x++; x < ys.size(); x += dx(x)) { | ~~^~~~~~~~~~~ main.cpp: In member function 'void Fenwick2D::update(int, int, int)': main.cpp:30:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | for (x++; x < ys.size(); x += dx(x)) { | ~~^~~~~~~~~~~ main.cpp:31:51: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | for (int i = ind(x, y); i < t[x].size(); i += dx(i)) { | ~~^~~~~~~~~~~~~