Compilare: main.cpp: In function 'coeficienti resolve(std::string)': main.cpp:23:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | while (i < s.size()) { | ~~^~~~~~~~~~ main.cpp:26:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | while (i < s.size() && s[i] != '+' && s[i] != '-') { | ~~^~~~~~~~~~ main.cpp:43:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 43 | if (i < s.size()) { | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:62:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for( i = 0; i < s.size() && s[i] != '='; ++i ) | ~~^~~~~~~~~~ main.cpp:66:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 66 | for( ++i; i < s.size(); ++i ) | ~~^~~~~~~~~~