Compilare: main.cpp: In function 'void z_(const std::string&)': main.cpp:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 29 | for(int i = 1; i < s.size(); i ++) | ~~^~~~~~~~~~ main.cpp: In function 'void precalc()': main.cpp:52:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | for(int i = 0; i < s.size(); i ++) | ~~^~~~~~~~~~ main.cpp:59:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 59 | for(int i = 0; i + (1 << shift) <= s.size(); i ++) | ~~~~~~~~~~~~~~~~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:78:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 78 | for(int i = 0; i < s.size(); i ++) | ~~^~~~~~~~~~ main.cpp:80:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | if(i + z[i] == s.size() && z[i]) | ~~~~~~~~~^~~~~~~~~~~