Compilare: main.cpp: In function 'int main()': main.cpp:35:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for (int i = 0; i < a.size(); ++i) { | ~~^~~~~~~~~~ main.cpp:51:5: warning: 'ok' may be used uninitialized in this function [-Wmaybe-uninitialized] 51 | if (ok) | ^~