Compilare: main.cpp: In function 'int main()': main.cpp:50:28: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 50 | for(long long i = 0; i < a.size(); i ++) | ~~^~~~~~~~~~ main.cpp:62:35: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for(long long i = a.size(); i < b.size(); i ++) | ~~^~~~~~~~~~