Compilare: main.cpp: In function 'int main()': main.cpp:16:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 16 | for(int i=0;i<s.size();i++) | ~^~~~~~~~~ main.cpp:18:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for(int j=i+1;j<s.size();j++) | ~^~~~~~~~~