Compilare: main.cpp: In function 'int main()': main.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | for (int i = 1; i < a.size(); ++i) { | ~~^~~~~~~~~~ main.cpp:28:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for (int i = 0; i < b.size(); ++i) { | ~~^~~~~~~~~~ main.cpp:35:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | if (l == a.size()) { | ~~^~~~~~~~~~~