Compilare: main.cpp: In function 'int main()': main.cpp:27:19: 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] 27 | for(int i=1; i<=s.size(); i++) | ~^~~~~~~~~~ main.cpp:46:14: 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] 46 | if(i > s.size()) | ~~^~~~~~~~~~