Compilare: main.cpp: In function 'void eval(std::string)': main.cpp:12:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | for (int i = 0; i < c.size() && ok; i++) | ~~^~~~~~~~~~ main.cpp: In function 'void solve()': 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 < aux.size() - 1; ++i) | ~~^~~~~~~~~~~~~~~~