Compilare: main.cpp: In instantiation of 'void Fenwick2D<func>::fakeUpdate(int, int) [with const int& (* func)(const int&, const int&) = std::max<int>]': main.cpp:65:17: required from here main.cpp:18:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for (x++; x < ys.size(); x += dx(x)) { | ~~^~~~~~~~~~~ main.cpp: In instantiation of 'void Fenwick2D<func>::update(int, int, int) [with const int& (* func)(const int&, const int&) = std::max<int>]': main.cpp:70:12: required from here main.cpp:32:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | for (x++; x < ys.size(); x += dx(x)) { | ~~^~~~~~~~~~~ main.cpp:33:51: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | for (int i = ind(x, y); i < t[x].size(); i += dx(i)) { | ~~^~~~~~~~~~~~~