Compilare: main.cpp: In function 'int main()': main.cpp:21:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | while (i < s.size()) | ~~^~~~~~~~~~ main.cpp:31:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | while (i < s.size() and isdigit(s[i])) | ~~^~~~~~~~~~ main.cpp:69:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 69 | for (i = 0; i < a1.size(); i++) | ~~^~~~~~~~~~~