Compilare: main.cpp: In function 'int main()': main.cpp:14:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 14 | for(int i = 2; i <= s.size(); i++) | ~~^~~~~~~~~~~ main.cpp:21:51: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 21 | if(i - pi[i] >= pi[i] && s.size() - pi[i] >= i) | ~~~~~~~~~~~~~~~~~^~~~