Compilare: main.cpp: In function 'int main()': main.cpp:42:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | for (int i=1;i<a.size();i++){ | ~^~~~~~~~~ main.cpp:51:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 51 | for (int i=0;i<b.size();i++) { | ~^~~~~~~~~ main.cpp:56:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 56 | if (k == a.size() - 1) { | ~~^~~~~~~~~~~~~~~