Compilare: main.cpp: In function 'int main()': main.cpp:73:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 73 | for(int j=0;j<s.size();j++) | ~^~~~~~~~~ main.cpp:89:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 89 | for(int j=s.size()-u+1;j<s.size();j++) | ~^~~~~~~~~