Compilare: main.cpp: In function 'int main()': main.cpp:31:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | for (int i=0; i<a.size(); i++){ | ~^~~~~~~~~ main.cpp:35:20: 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<b.size(); i++){ | ~^~~~~~~~~ main.cpp:36:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | if (i<a.size()){ | ~^~~~~~~~~