Compilare: main.cpp: In function 'bool check(int, const std::vector<std::__cxx11::basic_string<char> >&)': main.cpp:15:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for (int k = 0; k < s.size(); ++k) { | ~~^~~~~~~~~~ main.cpp:16:33: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 16 | if (s[k].size() < len) { | ~~~~~~~~~~~~^~~~~ main.cpp:22:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for (int i = 0; i < s[k].size(); ++i) { | ~~^~~~~~~~~~~~~ main.cpp:20:21: warning: unused variable 'mask' [-Wunused-variable] 20 | ull mask = (1ULL << len) - 1, h = 0; | ^~~~