Compilare: main.cpp: In function 'int to_number(std::string)': main.cpp:10:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 10 | for(i=0;i<aux.size();i++){ | ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:18:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for(i=0;i<line.size();i++){ | ~^~~~~~~~~~~~