Compilare: main.cpp: In function 'int main()': main.cpp:14:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 14 | for(int j=1;j<=b.size();j++) | ~^~~~~~~~~~ main.cpp:17:18: 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++) | ~^~~~~~~~~~