Compilare: main.cpp: In function 'std::string add(std::string, std::string)': main.cpp:13:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'const long unsigned int' [-Wsign-compare] 13 | for (int i = 0; i < max(a.size(), b.size()); i++){ | ~~^~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:14:11: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 14 | if (i < a.size()) carry+=a[i] - '0'; | ~~^~~~~~~~~~ main.cpp:15:11: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | if (i < b.size()) carry+=b[i] - '0'; | ~~^~~~~~~~~~