Compilare: main.cpp: In function 'long long int CheckInt(std::string)': main.cpp:17:16: 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] 17 | for (i=0; i<s.size(); i++) | ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:24:8: warning: unused variable 'i' [-Wunused-variable] 24 | ll i,x,y; | ^