Compilare: main.cpp: In member function 'void rollingHash::init(std::string)': main.cpp:17:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | for ( i = 1; i <= s.size(); i++ ) { | ~~^~~~~~~~~~~